path-tool: Add a dash command

This is the obvious wrapper around gsk_path_dash.

.gitlab-ci.yml

@@ -30,8 +30,16 @@ variables:
 
 workflow:
   rules:
-    - if: $CI_COMMIT_TAG
+    # run merge request pipelines
+    - if: $CI_PIPELINE_SOURCE == "merge_request_event"
+    # do not run branch pipelines if corresponding merge requests exist...
+    # (this avoids duplicate pipelines)
+    - if: $CI_COMMIT_BRANCH && $CI_OPEN_MERGE_REQUESTS
+      when: never
+    # ...but otherwise run branch pipelines
     - if: $CI_COMMIT_BRANCH
+    # run tag pipelines
+    - if: $CI_COMMIT_TAG
 
 default:
   retry:
@@ -197,21 +205,30 @@ msys2-mingw64:
     paths:
       - "${CI_PROJECT_DIR}/_build/gtkdll.tar.gz"
 
-macos:
-  # Sadly, this fails regularly, and its failure is never enlightening
-  allow_failure: true
+macos-x86_64:
   rules:
+    # Do not run in forks as the runner is not available there.
     - if: $CI_PROJECT_NAMESPACE == "GNOME"
   stage: build
   tags:
-    - macos
+    - macosintel
   needs: []
+  variables:
+    MESON_FORCE_BACKTRACKE: 1
+    TMPDIR: /Users/Shared/work/tmp
+    SDKROOT: /opt/sdks/MacOSX10.13.4.sdk
+    CCACHE_DIR: /Users/Shared/work/ccache
+    PIP_CACHE_DIR: /Users/Shared/build/cache
+    PIPENV_CACHE_DIR: $PIP_CACHE_DIR
+    PYTHONPYCACHEPREFIX: $PIP_CACHE_DIR
   before_script:
     - bash .gitlab-ci/show-info-osx.sh
-    - pip3 install --user meson~=1.0
-    - pip3 install --user ninja
-    - export PATH=/Users/gitlabrunner/Library/Python/3.7/bin:$PATH
-    - export MESON_FORCE_BACKTRACE=1
+    - python3 -m venv .venv
+    - ln -s /opt/cmake/CMake.app/Contents/bin/cmake .venv/bin
+    - ln -s /opt/ccache/ccache .venv/bin
+    - source .venv/bin/activate
+    - pip3 install meson==1.2.0
+    - pip3 install ninja==1.11.1
   script:
     - meson setup ${COMMON_MESON_FLAGS}
             -Dx11-backend=false

.gitlab-ci/test-msvc.bat

@@ -6,7 +6,7 @@ call "C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\Auxiliar
 
 :: FIXME: make warnings fatal
 pip3 install --upgrade --user meson~=0.64 || goto :error
-meson -Ddebug=false -Dmedia-gstreamer=disabled _build || goto :error
+meson setup -Dbackend_max_links=1 -Ddebug=false -Dmedia-gstreamer=disabled _build || goto :error
 ninja -C _build || goto :error
 
 goto :EOF

NEWS

@@ -1,6 +1,81 @@
-Overview of Changes in 4.13.0, xx-xx-xxxx
+Overview of Changes in 4.13.1, xx-xx-xxxx
 =========================================
 
+Overview of Changes in 4.13.0, 25-08-2023
+=========================================
+
+* GskPath, GskPathBuilder, GskPathMeasure:
+  Data types and APIs for path rendering. These APIs are still
+  considered experimental, and may change until 4.14. Please try
+  them out and give us feedback. Documentation can be found
+  here: https://docs.gtk.org/gsk4/paths.html
+
+* GtkGridView:
+ - Fix a crash when scrolling
+
+* GtkColumnView:
+ - Fix a refcounting issue in the new scroll_to api
+
+* GtkTreeView
+ - Fix style classes for sort arrows
+
+* GtkEntry:
+ - Improve tracking of user changes (for undo)
+
+* GtkNotebook:
+ - Fix a critical when switching pages
+
+* GtkColor/FontDialogButton:
+ - Make these widgets activatable
+
+* GtkMenuButton:
+ - Fix problems with focus handling
+ - Fix problems with DND
+ - Make flags a settable property
+
+* GtkShortcutsWindow:
+ - Add API to build shortcuts windows programmatically
+
+* Printing
+ - Fix the cpdb backend build
+
+* MacOS:
+ - Make file filters work again
+
+* GSK:
+ - Fix issues with color matrix nodes
+
+* Wayland:
+ - Fix a crash with compositors other than gnome-shell
+
+* Deprecations:
+ - Remaining GtkTreeModel-related types
+
+* Demos:
+ - Add a few path demos to gtk4-demo
+
+* Tools:
+ - gtk4-path-tool provides a commandline interface for paths
+
+* Translation updates:
+ Basque
+ Catalan
+ Finnish
+ Galician
+ Georgian
+ German
+ Greek
+ Indonesian
+ Kazakh
+ Persian
+ Polish
+ Romanian
+ Spanish
+ Swedish
+ Turkish
+ Ukrainian
+
+
 Overview of Changes in 4.12.0, 05-08-2023
 =========================================
 

demos/gtk-demo/demo.gresource.xml

@@ -127,6 +127,7 @@
     <file>fishbowl.ui</file>
     <file>gtkfishbowl.c</file>
     <file>gtkfishbowl.h</file>
+    <file>tiger.node</file>
   </gresource>
   <gresource prefix="/frames">
     <file>frames.ui</file>
@@ -335,6 +336,11 @@
     <file>paintable_symbolic.c</file>
     <file>panes.c</file>
     <file>password_entry.c</file>
+    <file>path_fill.c</file>
+    <file>path_maze.c</file>
+    <file>path_spinner.c</file>
+    <file>path_walk.c</file>
+    <file>path_text.c</file>
     <file>peg_solitaire.c</file>
     <file>pickers.c</file>
     <file>printing.c</file>
@@ -420,6 +426,13 @@
   <gresource prefix="/fontrendering">
     <file>fontrendering.ui</file>
   </gresource>
+  <gresource prefix="/path_walk">
+    <file>path_walk.ui</file>
+    <file compressed="true">path_world.txt</file>
+  </gresource>
+  <gresource prefix="/path_text">
+    <file>path_text.ui</file>
+  </gresource>
   <gresource prefix="/org/gtk/Demo4">
     <file>icons/16x16/actions/application-exit.png</file>
     <file>icons/16x16/actions/document-new.png</file>

demos/gtk-demo/fishbowl.c

@@ -11,6 +11,9 @@
 #include "gtkgears.h"
 #include "gskshaderpaintable.h"
 
+#include "nodewidget.h"
+#include "graphwidget.h"
+
 const char *const css =
 ".blurred-button {"
 "  box-shadow: 0px 0px 5px 10px rgba(0, 0, 0, 0.5);"
@@ -208,6 +211,18 @@ create_menu_button (void)
   return w;
 }
 
+static GtkWidget *
+create_tiger (void)
+{
+  return node_widget_new ("/fishbowl/tiger.node");
+}
+
+static GtkWidget *
+create_graph (void)
+{
+  return graph_widget_new ();
+}
+
 static const struct {
   const char *name;
   GtkWidget * (*create_func) (void);
@@ -225,6 +240,8 @@ static const struct {
   { "Switch",     create_switch         },
   { "Menubutton", create_menu_button    },
   { "Shader",     create_cogs           },
+  { "Tiger",      create_tiger          },
+  { "Graph",      create_graph          },
 };
 
 static int selected_widget_type = -1;

demos/gtk-demo/graphwidget.c

@@ -0,0 +1,153 @@
+#include "graphwidget.h"
+
+struct _GraphWidget
+{
+  GtkWidget parent_instance;
+
+  GskPath *path;
+  GskStroke *stroke;
+  GdkRGBA color;
+
+  guint tick_cb;
+  guint64 start_time;
+
+  double period;
+  double amplitude;
+};
+
+struct _GraphWidgetClass
+{
+  GtkWidgetClass parent_class;
+};
+
+G_DEFINE_TYPE (GraphWidget, graph_widget, GTK_TYPE_WIDGET)
+
+static void
+update_path (GraphWidget *self,
+             float        amplitude)
+{
+  graphene_point_t p[20];
+  GskPathBuilder *builder;
+
+  g_clear_pointer (&self->path, gsk_path_unref);
+
+  for (int i = 0; i < 20; i++)
+    {
+      p[i].x = 10 * i;
+      p[i].y = 50;
+
+      if (i % 4 == 1 || i % 4 == 2)
+        {
+          if (i % 8 < 4)
+            p[i].y += amplitude;
+          else
+            p[i].y -= amplitude;
+        }
+    }
+
+  builder = gsk_path_builder_new ();
+  gsk_path_builder_move_to (builder, p[0].x, p[0].y);
+
+  for (int i = 0; i < 20; i += 4)
+    gsk_path_builder_cubic_to (builder,
+                               p[i+1].x, p[i+1].y,
+                               p[i+2].x, p[i+2].y,
+                               p[i+3].x, p[i+3].y);
+
+  self->path = gsk_path_builder_free_to_path (builder);
+}
+
+static gboolean
+tick_cb (GtkWidget     *widget,
+         GdkFrameClock *frame_clock,
+         gpointer       user_data)
+{
+  GraphWidget *self = GRAPH_WIDGET (widget);
+  guint64 now;
+  double angle;
+
+  now = gdk_frame_clock_get_frame_time (frame_clock);
+
+  if (self->start_time == 0)
+    self->start_time = now;
+
+  angle = 360 * (now - self->start_time) / (double)(self->period * G_TIME_SPAN_MINUTE);
+  update_path (self, sin (angle) * self->amplitude);
+
+  gtk_widget_queue_draw (widget);
+
+  return G_SOURCE_CONTINUE;
+}
+
+static void
+graph_widget_init (GraphWidget *self)
+{
+  self->color.red = g_random_double_range (0, 1);
+  self->color.green = g_random_double_range (0, 1);
+  self->color.blue = g_random_double_range (0, 1);
+  self->color.alpha = 1;
+
+  self->period = g_random_double_range (0.5, 1);
+  self->amplitude = g_random_double_range (10, 25);
+
+  self->stroke = gsk_stroke_new (2);
+
+  update_path (self, 0);
+
+  self->start_time = 0;
+  self->tick_cb = gtk_widget_add_tick_callback (GTK_WIDGET (self), tick_cb, NULL, NULL);
+}
+
+static void
+graph_widget_dispose (GObject *object)
+{
+  GraphWidget *self = GRAPH_WIDGET (object);
+
+  g_clear_pointer (&self->path, gsk_path_unref);
+  gsk_stroke_free (self->stroke);
+
+  G_OBJECT_CLASS (graph_widget_parent_class)->dispose (object);
+}
+
+static void
+graph_widget_snapshot (GtkWidget   *widget,
+                      GtkSnapshot *snapshot)
+{
+  GraphWidget *self = GRAPH_WIDGET (widget);
+
+  gtk_snapshot_append_stroke (snapshot, self->path, self->stroke, &self->color);
+}
+
+static void
+graph_widget_measure (GtkWidget      *widget,
+                      GtkOrientation  orientation,
+                      int             for_size,
+                      int            *minimum,
+                      int            *natural,
+                      int            *minimum_baseline,
+                      int            *natural_baseline)
+{
+  if (orientation == GTK_ORIENTATION_HORIZONTAL)
+    *minimum = *natural = 200;
+  else
+    *minimum = *natural = 100;
+}
+
+
+static void
+graph_widget_class_init (GraphWidgetClass *class)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
+
+  object_class->dispose = graph_widget_dispose;
+
+  widget_class->snapshot = graph_widget_snapshot;
+  widget_class->measure = graph_widget_measure;
+}
+
+GtkWidget *
+graph_widget_new (void)
+{
+  return g_object_new (GRAPH_TYPE_WIDGET, NULL);
+}

demos/gtk-demo/graphwidget.h

@@ -0,0 +1,8 @@
+#pragma once
+
+#include <gtk/gtk.h>
+
+#define GRAPH_TYPE_WIDGET (graph_widget_get_type ())
+G_DECLARE_FINAL_TYPE (GraphWidget, graph_widget, GRAPH, WIDGET, GtkWidget)
+
+GtkWidget * graph_widget_new       (void);

demos/gtk-demo/gtkgears.c

@@ -840,24 +840,24 @@ gtk_gears_unrealize (GtkWidget *widget)
   GtkGearsPrivate *priv = gtk_gears_get_instance_private ((GtkGears *) widget);
 
   gtk_gl_area_make_current (glarea);
-  if (gtk_gl_area_get_error (glarea) != NULL)
-    return;
+  if (gtk_gl_area_get_error (glarea) == NULL)
+    {
+      /* Release the resources associated with OpenGL */
+      if (priv->gear_vbo[0] != 0)
+        glDeleteBuffers (1, &(priv->gear_vbo[0]));
 
-  /* Release the resources associated with OpenGL */
-  if (priv->gear_vbo[0] != 0)
-    glDeleteBuffers (1, &(priv->gear_vbo[0]));
+      if (priv->gear_vbo[1] != 0)
+        glDeleteBuffers (1, &(priv->gear_vbo[1]));
 
-  if (priv->gear_vbo[1] != 0)
-    glDeleteBuffers (1, &(priv->gear_vbo[1]));
+      if (priv->gear_vbo[2] != 0)
+        glDeleteBuffers (1, &(priv->gear_vbo[2]));
 
-  if (priv->gear_vbo[2] != 0)
-    glDeleteBuffers (1, &(priv->gear_vbo[2]));
+      if (priv->vao != 0)
+        glDeleteVertexArrays (1, &priv->vao);
 
-  if (priv->vao != 0)
-    glDeleteVertexArrays (1, &priv->vao);
-
-  if (priv->program != 0)
-    glDeleteProgram (priv->program);
+      if (priv->program != 0)
+        glDeleteProgram (priv->program);
+    }
 
   priv->ModelViewProjectionMatrix_location = 0;
   priv->NormalMatrix_location = 0;

demos/gtk-demo/meson.build

@@ -72,6 +72,11 @@ demos = files([
   'paintable_symbolic.c',
   'panes.c',
   'password_entry.c',
+  'path_fill.c',
+  'path_maze.c',
+  'path_spinner.c',
+  'path_walk.c',
+  'path_text.c',
   'peg_solitaire.c',
   'pickers.c',
   'printing.c',
@@ -136,6 +141,8 @@ extra_demo_sources = files([
   'unicode-names.c',
   'suggestionentry.c',
   'language-names.c',
+  'nodewidget.c',
+  'graphwidget.c',
 ])
 
 if os_unix

demos/gtk-demo/nodewidget.c

@@ -0,0 +1,76 @@
+#include "nodewidget.h"
+
+struct _NodeWidget
+{
+  GtkWidget parent_instance;
+
+  GskRenderNode *node;
+};
+
+struct _NodeWidgetClass
+{
+  GtkWidgetClass parent_class;
+};
+
+G_DEFINE_TYPE (NodeWidget, node_widget, GTK_TYPE_WIDGET)
+
+static void
+node_widget_init (NodeWidget *self)
+{
+}
+
+static void
+node_widget_dispose (GObject *object)
+{
+  NodeWidget *self = NODE_WIDGET (object);
+
+  gsk_render_node_unref (self->node);
+
+  G_OBJECT_CLASS (node_widget_parent_class)->dispose (object);
+}
+
+static void
+node_widget_snapshot (GtkWidget   *widget,
+                      GtkSnapshot *snapshot)
+{
+  NodeWidget *self = NODE_WIDGET (widget);
+
+  gtk_snapshot_append_node (snapshot, self->node);
+}
+
+static void
+node_widget_class_init (NodeWidgetClass *class)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
+
+  object_class->dispose = node_widget_dispose;
+
+  widget_class->snapshot = node_widget_snapshot;
+}
+
+GtkWidget *
+node_widget_new (const char *resource)
+{
+  NodeWidget *self;
+  GBytes *bytes;
+  GskRenderNode *node;
+  graphene_rect_t bounds;
+  float scale;
+  GskTransform *transform;
+
+  self = g_object_new (NODE_TYPE_WIDGET, NULL);
+
+  bytes = g_resources_lookup_data (resource, 0, NULL);
+  node = gsk_render_node_deserialize (bytes, NULL, NULL);
+  g_bytes_unref (bytes);
+
+  gsk_render_node_get_bounds (node, &bounds);
+  scale = MIN (100.0/bounds.size.width, 100.0/bounds.size.height);
+  transform = gsk_transform_scale (NULL, scale, scale);
+  self->node = gsk_transform_node_new (node, transform);
+  gsk_transform_unref (transform);
+  gsk_render_node_unref (node);
+
+  return GTK_WIDGET (self);
+}

demos/gtk-demo/nodewidget.h

@@ -0,0 +1,8 @@
+#pragma once
+
+#include <gtk/gtk.h>
+
+#define NODE_TYPE_WIDGET (node_widget_get_type ())
+G_DECLARE_FINAL_TYPE (NodeWidget, node_widget, NODE, WIDGET, GtkWidget)
+
+GtkWidget * node_widget_new       (const char *file);

demos/gtk-demo/path_fill.c

@@ -0,0 +1,198 @@
+/* Path/Fill and Stroke
+ *
+ * This demo shows how to use GskPath to draw shapes that are (a bit)
+ * more complex than a rounded rectangle.
+ */
+
+#include <glib/gi18n.h>
+#include <gtk/gtk.h>
+
+#include "paintable.h"
+
+#define GTK_TYPE_LOGO_PAINTABLE (gtk_logo_paintable_get_type ())
+G_DECLARE_FINAL_TYPE (GtkLogoPaintable, gtk_logo_paintable, GTK, LOGO_PAINTABLE, GObject)
+
+struct _GtkLogoPaintable
+{
+  GObject parent_instance;
+
+  int width;
+  int height;
+  GskPath *path[3];
+  GdkRGBA color[3];
+
+  GskPath *stroke_path;
+  GskStroke *stroke1;
+  GskStroke *stroke2;
+  GdkRGBA stroke_color;
+};
+
+struct _GtkLogoPaintableClass
+{
+  GObjectClass parent_class;
+};
+
+static int
+gtk_logo_paintable_get_intrinsic_width (GdkPaintable *paintable)
+{
+  GtkLogoPaintable *self = GTK_LOGO_PAINTABLE (paintable);
+
+  return self->width;
+}
+
+static int
+gtk_logo_paintable_get_intrinsic_height (GdkPaintable *paintable)
+{
+  GtkLogoPaintable *self = GTK_LOGO_PAINTABLE (paintable);
+
+  return self->height;
+}
+
+static void
+gtk_logo_paintable_snapshot (GdkPaintable *paintable,
+                             GdkSnapshot  *snapshot,
+                             double        width,
+                             double        height)
+{
+  GtkLogoPaintable *self = GTK_LOGO_PAINTABLE (paintable);
+
+  for (unsigned int i = 0; i < 3; i++)
+    {
+      gtk_snapshot_push_fill (snapshot, self->path[i], GSK_FILL_RULE_WINDING);
+      gtk_snapshot_append_color (snapshot,
+                                 &self->color[i],
+                                 &GRAPHENE_RECT_INIT (0, 0, width, height));
+      gtk_snapshot_pop (snapshot);
+    }
+  for (unsigned int i = 0; i < 3; i++)
+    {
+      gtk_snapshot_push_stroke (snapshot, self->stroke_path, self->stroke1);
+      gtk_snapshot_append_color (snapshot,
+                                 &self->stroke_color,
+                                 &GRAPHENE_RECT_INIT (0, 0, width, height));
+      gtk_snapshot_pop (snapshot);
+    }
+
+  gtk_snapshot_push_stroke (snapshot, self->stroke_path, self->stroke2);
+  gtk_snapshot_append_color (snapshot,
+                             &self->stroke_color,
+                             &GRAPHENE_RECT_INIT (0, 0, width, height));
+  gtk_snapshot_pop (snapshot);
+}
+
+static GdkPaintableFlags
+gtk_logo_paintable_get_flags (GdkPaintable *paintable)
+{
+  return GDK_PAINTABLE_STATIC_CONTENTS | GDK_PAINTABLE_STATIC_SIZE;
+}
+
+static void
+gtk_logo_paintable_paintable_init (GdkPaintableInterface *iface)
+{
+  iface->get_intrinsic_width = gtk_logo_paintable_get_intrinsic_width;
+  iface->get_intrinsic_height = gtk_logo_paintable_get_intrinsic_height;
+  iface->snapshot = gtk_logo_paintable_snapshot;
+  iface->get_flags = gtk_logo_paintable_get_flags;
+}
+
+/* When defining the GType, we need to implement the GdkPaintable interface */
+G_DEFINE_TYPE_WITH_CODE (GtkLogoPaintable, gtk_logo_paintable, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (GDK_TYPE_PAINTABLE,
+                                                gtk_logo_paintable_paintable_init))
+
+static void
+gtk_logo_paintable_dispose (GObject *object)
+{
+  GtkLogoPaintable *self = GTK_LOGO_PAINTABLE (object);
+
+  for (unsigned int i = 0; i < 3; i++)
+    gsk_path_unref (self->path[i]);
+
+  gsk_path_unref (self->stroke_path);
+
+  gsk_stroke_free (self->stroke1);
+  gsk_stroke_free (self->stroke2);
+
+  G_OBJECT_CLASS (gtk_logo_paintable_parent_class)->dispose (object);
+}
+
+static void
+gtk_logo_paintable_class_init (GtkLogoPaintableClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = gtk_logo_paintable_dispose;
+}
+
+static void
+gtk_logo_paintable_init (GtkLogoPaintable *self)
+{
+}
+
+static GdkPaintable *
+gtk_logo_paintable_new (void)
+{
+  GtkLogoPaintable *self;
+  graphene_rect_t bounds, bounds2;
+
+  self = g_object_new (GTK_TYPE_LOGO_PAINTABLE, NULL);
+
+  /* Paths and colors extracted from gtk-logo.svg */
+  self->path[0] = gsk_path_parse ("m3.12,66.17 -2.06,-51.46 32.93,24.7 v55.58 l-30.87,-28.82 z");
+  self->path[1] = gsk_path_parse ("m34,95 49.4,-20.58 4.12,-51.46 -53.52,16.47 v55.58 z");
+  self->path[2] = gsk_path_parse ("m1.06,14.71 32.93,24.7 53.52,-16.47 -36.75,-21.88 -49.7,13.65 z");
+
+  gdk_rgba_parse (&self->color[0], "#e40000");
+  gdk_rgba_parse (&self->color[1], "#7fe719");
+  gdk_rgba_parse (&self->color[2], "#729fcf");
+
+  self->stroke_path = gsk_path_parse ("m50.6,51.3 -47.3,14 z l33,23 z v-50");
+  self->stroke1 = gsk_stroke_new (2.12);
+  self->stroke2 = gsk_stroke_new (1.25);
+  gdk_rgba_parse (&self->stroke_color, "#ffffff");
+
+  gsk_path_get_stroke_bounds (self->path[0], self->stroke1, &bounds);
+  gsk_path_get_stroke_bounds (self->path[1], self->stroke1, &bounds2);
+  graphene_rect_union (&bounds, &bounds2, &bounds);
+  gsk_path_get_stroke_bounds (self->path[2], self->stroke1, &bounds2);
+  graphene_rect_union (&bounds, &bounds2, &bounds);
+  gsk_path_get_stroke_bounds (self->stroke_path, self->stroke2, &bounds2);
+  graphene_rect_union (&bounds, &bounds2, &bounds);
+
+  self->width = bounds.origin.x + bounds.size.width;
+  self->height = bounds.origin.y + bounds.size.height;
+
+  return GDK_PAINTABLE (self);
+}
+
+GtkWidget *
+do_path_fill (GtkWidget *do_widget)
+{
+  static GtkWidget *window = NULL;
+
+  if (!window)
+    {
+      GtkWidget *picture;
+      GdkPaintable *paintable;
+
+      window = gtk_window_new ();
+      gtk_window_set_resizable (GTK_WINDOW (window), TRUE);
+      gtk_window_set_title (GTK_WINDOW (window), "Fill and Stroke");
+      g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
+
+      paintable = gtk_logo_paintable_new ();
+      picture = gtk_picture_new_for_paintable (paintable);
+      gtk_picture_set_content_fit (GTK_PICTURE (picture), GTK_CONTENT_FIT_CONTAIN);
+      gtk_picture_set_can_shrink (GTK_PICTURE (picture), FALSE);
+      g_object_unref (paintable);
+
+      gtk_window_set_child (GTK_WINDOW (window), picture);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_window_present (GTK_WINDOW (window));
+  else
+    gtk_window_destroy (GTK_WINDOW (window));
+
+  return window;
+}

demos/gtk-demo/path_maze.c

@@ -0,0 +1,348 @@
+/* Path/Maze
+ *
+ * This demo shows how to use a GskPath to create a maze and use
+ * gsk_path_get_closest_point() to check the mouse stays
+ * on the path.
+ *
+ * It also shows off the performance of GskPath (or not) as this
+ * is a rather complex path.
+ */
+
+#include <glib/gi18n.h>
+#include <gtk/gtk.h>
+
+#include "paintable.h"
+
+#define MAZE_GRID_SIZE 20
+#define MAZE_STROKE_SIZE_ACTIVE (MAZE_GRID_SIZE - 4)
+#define MAZE_STROKE_SIZE_INACTIVE (MAZE_GRID_SIZE - 12)
+#define MAZE_WIDTH 31
+#define MAZE_HEIGHT 21
+
+#define GTK_TYPE_MAZE (gtk_maze_get_type ())
+G_DECLARE_FINAL_TYPE (GtkMaze, gtk_maze, GTK, MAZE, GtkWidget)
+
+struct _GtkMaze
+{
+  GtkWidget parent_instance;
+
+  int width;
+  int height;
+  GskPath *path;
+  GskPathMeasure *measure;
+  GdkPaintable *background;
+
+  gboolean active;
+};
+
+struct _GtkMazeClass
+{
+  GtkWidgetClass parent_class;
+};
+
+G_DEFINE_TYPE (GtkMaze, gtk_maze, GTK_TYPE_WIDGET)
+
+static void
+gtk_maze_measure (GtkWidget      *widget,
+                  GtkOrientation  orientation,
+                  int             for_size,
+                  int            *minimum,
+                  int            *natural,
+                  int            *minimum_baseline,
+                  int            *natural_baseline)
+{
+  GtkMaze *self = GTK_MAZE (widget);
+
+  if (orientation == GTK_ORIENTATION_HORIZONTAL)
+    *minimum = *natural = self->width;
+  else
+    *minimum = *natural = self->height;
+}
+
+static void
+gtk_maze_snapshot (GtkWidget   *widget,
+                   GdkSnapshot *snapshot)
+{
+  GtkMaze *self = GTK_MAZE (widget);
+  double width = gtk_widget_get_width (widget);
+  double height = gtk_widget_get_height (widget);
+  GskStroke *stroke;
+
+  stroke = gsk_stroke_new (MAZE_STROKE_SIZE_INACTIVE);
+  if (self->active)
+    gsk_stroke_set_line_width (stroke, MAZE_STROKE_SIZE_ACTIVE);
+  gsk_stroke_set_line_join (stroke, GSK_LINE_JOIN_ROUND);
+  gsk_stroke_set_line_cap (stroke, GSK_LINE_CAP_ROUND);
+  gtk_snapshot_push_stroke (snapshot, self->path, stroke);
+  gsk_stroke_free (stroke);
+
+  if (self->background)
+    {
+      gdk_paintable_snapshot (self->background, snapshot, width, height);
+    }
+  else
+    {
+      gtk_snapshot_append_linear_gradient (snapshot,
+                                           &GRAPHENE_RECT_INIT (0, 0, width, height),
+                                           &GRAPHENE_POINT_INIT (0, 0),
+                                           &GRAPHENE_POINT_INIT (width, height),
+                                           (GskColorStop[8]) {
+                                             { 0.0, { 1.0, 0.0, 0.0, 1.0 } },
+                                             { 0.2, { 1.0, 0.0, 0.0, 1.0 } },
+                                             { 0.3, { 1.0, 1.0, 0.0, 1.0 } },
+                                             { 0.4, { 0.0, 1.0, 0.0, 1.0 } },
+                                             { 0.6, { 0.0, 1.0, 1.0, 1.0 } },
+                                             { 0.7, { 0.0, 0.0, 1.0, 1.0 } },
+                                             { 0.8, { 1.0, 0.0, 1.0, 1.0 } },
+                                             { 1.0, { 1.0, 0.0, 1.0, 1.0 } }
+                                           },
+                                           8);
+    }
+
+  gtk_snapshot_pop (snapshot);
+
+}
+
+static void
+gtk_maze_dispose (GObject *object)
+{
+  GtkMaze *self = GTK_MAZE (object);
+
+  g_clear_pointer (&self->path, gsk_path_unref);
+  g_clear_pointer (&self->measure, gsk_path_measure_unref);
+  if (self->background)
+    {
+      g_signal_handlers_disconnect_matched (self->background, G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, self);
+      g_clear_object (&self->background);
+    }
+
+  G_OBJECT_CLASS (gtk_maze_parent_class)->dispose (object);
+}
+
+static void
+gtk_maze_class_init (GtkMazeClass *klass)
+{
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = gtk_maze_dispose;
+
+  widget_class->measure = gtk_maze_measure;
+  widget_class->snapshot = gtk_maze_snapshot;
+}
+
+static void
+pointer_motion (GtkEventControllerMotion *controller,
+                double                    x,
+                double                    y,
+                GtkMaze                  *self)
+{
+  GskPathPoint point;
+  float distance;
+
+  if (!self->active)
+    return;
+
+  if (gsk_path_get_closest_point (self->path,
+                                  &GRAPHENE_POINT_INIT (x, y),
+                                  INFINITY,
+                                  &point,
+                                  &distance))
+    {
+      if (distance < MAZE_STROKE_SIZE_ACTIVE / 2.f)
+        return;
+    }
+
+  self->active = FALSE;
+  gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+pointer_leave (GtkEventControllerMotion *controller,
+               GtkMaze                  *self)
+{
+  if (!self->active)
+    {
+      self->active = TRUE;
+      gtk_widget_queue_draw (GTK_WIDGET (self));
+    }
+}
+
+static void
+gtk_maze_init (GtkMaze *self)
+{
+  GtkEventController *controller;
+
+  controller = GTK_EVENT_CONTROLLER (gtk_event_controller_motion_new ());
+  g_signal_connect (controller, "motion", G_CALLBACK (pointer_motion), self);
+  g_signal_connect (controller, "leave", G_CALLBACK (pointer_leave), self);
+  gtk_widget_add_controller (GTK_WIDGET (self), controller);
+
+  self->active = TRUE;
+}
+
+static void
+gtk_maze_set_path (GtkMaze *self,
+                   GskPath *path)
+{
+  g_clear_pointer (&self->path, gsk_path_unref);
+  g_clear_pointer (&self->measure, gsk_path_measure_unref);
+  self->path = gsk_path_ref (path);
+  self->measure = gsk_path_measure_new (path);
+
+  gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+GtkWidget *
+gtk_maze_new (GskPath      *path,
+              GdkPaintable *background,
+              int           width,
+              int           height)
+{
+  GtkMaze *self;
+
+  self = g_object_new (GTK_TYPE_MAZE, NULL);
+
+  gtk_maze_set_path (self, path);
+  gsk_path_unref (path);
+  self->background = background;
+  if (self->background)
+    {
+      g_signal_connect_swapped (self->background, "invalidate-contents", G_CALLBACK (gtk_widget_queue_draw), self);
+      g_signal_connect_swapped (self->background, "invalidate-size", G_CALLBACK (gtk_widget_queue_resize), self);
+    }
+  self->width = width;
+  self->height = height;
+
+  return GTK_WIDGET (self);
+}
+
+static void
+add_point_to_maze (GtkBitset      *maze,
+                   GskPathBuilder *builder,
+                   guint           x,
+                   guint           y)
+{
+  gboolean set[4] = { FALSE, FALSE, FALSE, FALSE };
+  guint dir;
+
+  gtk_bitset_add (maze, y * MAZE_WIDTH + x);
+
+  while (TRUE)
+    {
+      set[0] = set[0] || x == 0 || gtk_bitset_contains (maze, y * MAZE_WIDTH + x - 1);
+      set[1] = set[1] || y == 0 || gtk_bitset_contains (maze, (y - 1) * MAZE_WIDTH + x);
+      set[2] = set[2] || x + 1 == MAZE_WIDTH || gtk_bitset_contains (maze, y * MAZE_WIDTH + x + 1);
+      set[3] = set[3] || y + 1 == MAZE_HEIGHT || gtk_bitset_contains (maze, (y + 1) * MAZE_WIDTH + x);
+
+      if (set[0] && set[1] && set[2] && set[3])
+        return;
+      
+      do
+        {
+          dir = g_random_int_range (0, 4);
+        }
+      while (set[dir]);
+
+      switch (dir)
+        {
+          case 0:
+            gsk_path_builder_move_to (builder, (x + 0.5) * MAZE_GRID_SIZE, (y + 0.5) * MAZE_GRID_SIZE);
+            gsk_path_builder_line_to (builder, (x - 0.5) * MAZE_GRID_SIZE, (y + 0.5) * MAZE_GRID_SIZE);
+            add_point_to_maze (maze, builder, x - 1, y);
+            break;
+
+          case 1:
+            gsk_path_builder_move_to (builder, (x + 0.5) * MAZE_GRID_SIZE, (y + 0.5) * MAZE_GRID_SIZE);
+            gsk_path_builder_line_to (builder, (x + 0.5) * MAZE_GRID_SIZE, (y - 0.5) * MAZE_GRID_SIZE);
+            add_point_to_maze (maze, builder, x, y - 1);
+            break;
+
+          case 2:
+            gsk_path_builder_move_to (builder, (x + 0.5) * MAZE_GRID_SIZE, (y + 0.5) * MAZE_GRID_SIZE);
+            gsk_path_builder_line_to (builder, (x + 1.5) * MAZE_GRID_SIZE, (y + 0.5) * MAZE_GRID_SIZE);
+            add_point_to_maze (maze, builder, x + 1, y);
+            break;
+
+          case 3:
+            gsk_path_builder_move_to (builder, (x + 0.5) * MAZE_GRID_SIZE, (y + 0.5) * MAZE_GRID_SIZE);
+            gsk_path_builder_line_to (builder, (x + 0.5) * MAZE_GRID_SIZE, (y + 1.5) * MAZE_GRID_SIZE);
+            add_point_to_maze (maze, builder, x, y + 1);
+            break;
+
+          default:
+            g_assert_not_reached ();
+            break;
+        }
+    }
+}
+
+static GskPath *
+create_path_for_maze (GtkWidget *widget)
+{
+  GskPathBuilder *builder;
+  GtkBitset *maze;
+
+  builder = gsk_path_builder_new ();
+  maze = gtk_bitset_new_empty ();
+  /* make sure the outer lines are unreachable:
+   * Set the full range, then remove the center again. */
+  gtk_bitset_add_range (maze, 0, MAZE_WIDTH * MAZE_HEIGHT);
+  gtk_bitset_remove_rectangle (maze, MAZE_WIDTH + 1, MAZE_WIDTH - 2, MAZE_HEIGHT - 2, MAZE_WIDTH);
+
+  /* Fill the maze */
+  add_point_to_maze (maze, builder, MAZE_WIDTH / 2, MAZE_HEIGHT / 2);
+
+  /* Add start and stop lines */
+  gsk_path_builder_move_to (builder, 1.5 * MAZE_GRID_SIZE, -0.5 * MAZE_GRID_SIZE);
+  gsk_path_builder_line_to (builder, 1.5 * MAZE_GRID_SIZE, 1.5 * MAZE_GRID_SIZE);
+  gsk_path_builder_move_to (builder, (MAZE_WIDTH - 1.5) * MAZE_GRID_SIZE, (MAZE_HEIGHT - 1.5) * MAZE_GRID_SIZE);
+  gsk_path_builder_line_to (builder, (MAZE_WIDTH - 1.5) * MAZE_GRID_SIZE, (MAZE_HEIGHT + 0.5) * MAZE_GRID_SIZE);
+
+
+  gtk_bitset_unref (maze);
+
+  return gsk_path_builder_free_to_path (builder);
+}
+
+GtkWidget *
+do_path_maze (GtkWidget *do_widget)
+{
+  static GtkWidget *window = NULL;
+
+  if (!window)
+    {
+      GtkWidget *maze;
+      GtkMediaStream *stream;
+      GskPath *path;
+
+      window = gtk_window_new ();
+      gtk_window_set_resizable (GTK_WINDOW (window), TRUE);
+      gtk_window_set_title (GTK_WINDOW (window), "Follow the maze with the mouse");
+      g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
+
+#if 0
+      stream = gtk_media_file_new_for_resource ("/images/gtk-logo.webm");
+#else
+      stream = gtk_nuclear_media_stream_new ();
+#endif
+      gtk_media_stream_play (stream);
+      gtk_media_stream_set_loop (stream, TRUE);
+
+      path = create_path_for_maze (window);
+
+      maze = gtk_maze_new (path,
+                           GDK_PAINTABLE (stream),
+                           MAZE_WIDTH * MAZE_GRID_SIZE,
+                           MAZE_HEIGHT * MAZE_GRID_SIZE);
+
+      gtk_window_set_child (GTK_WINDOW (window), maze);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_window_present (GTK_WINDOW (window));
+  else
+    gtk_window_destroy (GTK_WINDOW (window));
+
+  return window;
+}

demos/gtk-demo/path_spinner.c

@@ -0,0 +1,320 @@
+/* Path/Spinner
+ *
+ * This demo shows how to use GskPath to draw a simple animation
+ * that could be used as a spinner.
+ */
+
+#include <glib/gi18n.h>
+#include <gtk/gtk.h>
+
+#include "paintable.h"
+
+#define GTK_TYPE_SPINNER_PAINTABLE (gtk_spinner_paintable_get_type ())
+G_DECLARE_FINAL_TYPE (GtkSpinnerPaintable, gtk_spinner_paintable, GTK, SPINNER_PAINTABLE, GObject)
+
+struct _GtkSpinnerPaintable
+{
+  GObject parent_instance;
+
+  gint64 start_time;
+
+  int width;
+  double angle;
+  double completion;
+
+  GskPath *circle;
+  GskPath *path;
+  GskStroke *stroke;
+  GdkRGBA color;
+  GdkRGBA circle_color;
+#ifdef SHOW_CONTROLS
+  GskPath *controls;
+  GdkRGBA control_color;
+#endif
+};
+
+struct _GtkSpinnerPaintableClass
+{
+  GObjectClass parent_class;
+};
+
+static int
+gtk_spinner_paintable_get_intrinsic_width (GdkPaintable *paintable)
+{
+  GtkSpinnerPaintable *self = GTK_SPINNER_PAINTABLE (paintable);
+
+  return self->width;
+}
+
+static int
+gtk_spinner_paintable_get_intrinsic_height (GdkPaintable *paintable)
+{
+  GtkSpinnerPaintable *self = GTK_SPINNER_PAINTABLE (paintable);
+
+  return self->width;
+}
+
+static void
+gtk_spinner_paintable_snapshot (GdkPaintable *paintable,
+                                GdkSnapshot  *snapshot,
+                                double        width,
+                                double        height)
+{
+  GtkSpinnerPaintable *self = GTK_SPINNER_PAINTABLE (paintable);
+
+  gtk_snapshot_append_stroke (snapshot, self->circle, self->stroke, &self->circle_color);
+  gtk_snapshot_append_stroke (snapshot, self->path, self->stroke, &self->color);
+#ifdef SHOW_CONTROLS
+  GskStroke *stroke = gsk_stroke_new (1);
+  gtk_snapshot_append_stroke (snapshot, self->controls, stroke, &self->control_color);
+  gsk_stroke_free (stroke);
+#endif
+}
+
+static GdkPaintableFlags
+gtk_spinner_paintable_get_flags (GdkPaintable *paintable)
+{
+  return GDK_PAINTABLE_STATIC_SIZE;
+}
+
+static void
+gtk_spinner_paintable_paintable_init (GdkPaintableInterface *iface)
+{
+  iface->get_intrinsic_width = gtk_spinner_paintable_get_intrinsic_width;
+  iface->get_intrinsic_height = gtk_spinner_paintable_get_intrinsic_height;
+  iface->snapshot = gtk_spinner_paintable_snapshot;
+  iface->get_flags = gtk_spinner_paintable_get_flags;
+}
+
+/* When defining the GType, we need to implement the GdkPaintable interface */
+G_DEFINE_TYPE_WITH_CODE (GtkSpinnerPaintable, gtk_spinner_paintable, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (GDK_TYPE_PAINTABLE,
+                                                gtk_spinner_paintable_paintable_init))
+
+static void
+gtk_spinner_paintable_dispose (GObject *object)
+{
+  GtkSpinnerPaintable *self = GTK_SPINNER_PAINTABLE (object);
+
+  gsk_path_unref (self->circle);
+  gsk_path_unref (self->path);
+#ifdef SHOW_CONTROLS
+  gsk_path_unref (self->controls);
+#endif
+
+  gsk_stroke_free (self->stroke);
+
+  G_OBJECT_CLASS (gtk_spinner_paintable_parent_class)->dispose (object);
+}
+
+static void
+gtk_spinner_paintable_class_init (GtkSpinnerPaintableClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = gtk_spinner_paintable_dispose;
+}
+
+static void
+gtk_spinner_paintable_init (GtkSpinnerPaintable *self)
+{
+}
+
+static GdkPaintable *
+gtk_spinner_paintable_new (void)
+{
+  GtkSpinnerPaintable *self;
+  GskPathBuilder *builder;
+
+  self = g_object_new (GTK_TYPE_SPINNER_PAINTABLE, NULL);
+
+  builder = gsk_path_builder_new ();
+  gsk_path_builder_add_circle (builder, &GRAPHENE_POINT_INIT (50, 50), 40);
+  self->circle = gsk_path_builder_free_to_path (builder);
+
+  self->width = 100;
+  self->angle = 0;
+  self->completion = 1;
+  gdk_rgba_parse (&self->color, "green");
+  gdk_rgba_parse (&self->circle_color, "lightgray");
+#ifdef SHOW_CONTROLS
+  gdk_rgba_parse (&self->control_color, "black");
+#endif
+  self->stroke = gsk_stroke_new (5);
+
+  return GDK_PAINTABLE (self);
+}
+
+#ifdef SHOW_CONTROLS
+static gboolean
+add_controls (GskPathOperation        op,
+              const graphene_point_t *pts,
+              gsize                   n_pts,
+              gpointer                data)
+{
+  GskPathBuilder *builder = data;
+
+  switch (op)
+    {
+    case GSK_PATH_MOVE:
+      gsk_path_builder_move_to (builder, pts[0].x, pts[0].y);
+      break;
+
+    case GSK_PATH_CLOSE:
+    case GSK_PATH_LINE:
+      gsk_path_builder_line_to (builder, pts[1].x, pts[1].y);
+      break;
+
+    case GSK_PATH_QUAD:
+    case GSK_PATH_ARC:
+      gsk_path_builder_line_to (builder, pts[1].x, pts[1].y);
+      gsk_path_builder_line_to (builder, pts[2].x, pts[2].y);
+      break;
+
+    case GSK_PATH_CUBIC:
+      gsk_path_builder_line_to (builder, pts[1].x, pts[1].y);
+      gsk_path_builder_line_to (builder, pts[2].x, pts[2].y);
+      gsk_path_builder_line_to (builder, pts[3].x, pts[3].y);
+      break;
+
+    default:
+      g_assert_not_reached ();
+    }
+
+  return TRUE;
+}
+#endif
+
+static void
+update_path (GtkSpinnerPaintable *self)
+{
+  GskPathBuilder *builder;
+  GskPathPoint start, end;
+  graphene_point_t p0, p1;
+  float start_angle, end_angle;
+
+  start_angle = self->angle;
+  end_angle = fmod (self->angle + 360 * self->completion / 100, 360);
+
+  p0 = GRAPHENE_POINT_INIT (50 + 40 * cos (M_PI * start_angle / 180),
+                            50 + 40 * sin (M_PI * start_angle / 180));
+  p1 = GRAPHENE_POINT_INIT (50 + 40 * cos (M_PI * end_angle / 180),
+                            50 + 40 * sin (M_PI * end_angle / 180));
+
+  g_clear_pointer (&self->path, gsk_path_unref);
+
+  gsk_path_get_closest_point (self->circle, &p0, INFINITY, &start, NULL);
+  gsk_path_get_closest_point (self->circle, &p1, INFINITY, &end, NULL);
+
+  builder = gsk_path_builder_new ();
+  gsk_path_builder_add_segment (builder, self->circle, &start, &end);
+  self->path = gsk_path_builder_free_to_path (builder);
+
+#ifdef SHOW_CONTROLS
+  g_clear_pointer (&self->controls, gsk_path_unref);
+  builder = gsk_path_builder_new ();
+  gsk_path_foreach (self->path, -1, add_controls, builder);
+  self->controls = gsk_path_builder_free_to_path (builder);
+#endif
+
+  gdk_paintable_invalidate_contents (GDK_PAINTABLE (self));
+}
+
+static void
+gtk_spinner_paintable_set_completion (GtkSpinnerPaintable *self,
+                                   float             completion)
+{
+  self->completion = CLAMP (completion, 0, 100);
+  update_path (self);
+}
+
+static float
+gtk_spinner_paintable_get_completion (GtkSpinnerPaintable *self)
+{
+  return self->completion;
+}
+
+static void
+gtk_spinner_paintable_set_frame_time (GtkSpinnerPaintable *self,
+                                      gint64            time)
+{
+  double delta;
+
+  if (self->start_time == 0)
+    self->start_time = time;
+
+  delta = (time - self->start_time) / (double) G_TIME_SPAN_SECOND;
+  self->angle = fmod (60 * delta, 360);
+  update_path (self);
+}
+
+static gboolean
+tick_cb (GtkWidget *widget,
+         GdkFrameClock *clock,
+         gpointer data)
+{
+  GtkSpinnerPaintable *self = data;
+
+  gtk_spinner_paintable_set_frame_time (self, gdk_frame_clock_get_frame_time (clock));
+  return G_SOURCE_CONTINUE;
+}
+
+static gboolean
+progress_timeout (gpointer data)
+{
+  GtkSpinnerPaintable *self = data;
+  static float progress_delta = 0.5;
+  float progress;
+
+  progress = gtk_spinner_paintable_get_completion (self);
+  if (progress >= 100 || progress <= 0)
+    progress_delta = -progress_delta;
+
+  gtk_spinner_paintable_set_completion (self, progress + progress_delta);
+
+  return G_SOURCE_CONTINUE;
+}
+
+static void
+unset_timeout (gpointer data)
+{
+  g_source_remove (GPOINTER_TO_UINT (data));
+}
+
+GtkWidget *
+do_path_spinner (GtkWidget *do_widget)
+{
+  static GtkWidget *window = NULL;
+
+  if (!window)
+    {
+      GtkWidget *picture;
+      GdkPaintable *paintable;
+      guint timeout_id;
+
+      window = gtk_window_new ();
+      gtk_window_set_resizable (GTK_WINDOW (window), TRUE);
+      gtk_window_set_title (GTK_WINDOW (window), "Spinner");
+      g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
+
+      paintable = gtk_spinner_paintable_new ();
+      picture = gtk_picture_new_for_paintable (paintable);
+      gtk_picture_set_content_fit (GTK_PICTURE (picture), GTK_CONTENT_FIT_CONTAIN);
+      gtk_picture_set_can_shrink (GTK_PICTURE (picture), FALSE);
+      g_object_unref (paintable);
+
+      gtk_widget_add_tick_callback (picture, tick_cb, paintable, NULL);
+      timeout_id = g_timeout_add (100, progress_timeout, paintable);
+
+      g_object_set_data_full (G_OBJECT (picture), "timeout", GUINT_TO_POINTER (timeout_id), unset_timeout);
+
+      gtk_window_set_child (GTK_WINDOW (window), picture);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_window_present (GTK_WINDOW (window));
+  else
+    gtk_window_destroy (GTK_WINDOW (window));
+
+  return window;
+}

demos/gtk-demo/path_text.c

@@ -0,0 +1,584 @@
+/* Path/Text
+ *
+ * This demo shows how to use GskPath to transform a path along another path.
+ *
+ * It also demonstrates that paths can be filled with more interesting
+ * content than just plain colors.
+ */
+
+#include <glib/gi18n.h>
+#include <gtk/gtk.h>
+
+#define GTK_TYPE_PATH_WIDGET (gtk_path_widget_get_type ())
+G_DECLARE_FINAL_TYPE (GtkPathWidget, gtk_path_widget, GTK, PATH_WIDGET, GtkWidget)
+
+#define POINT_SIZE 8
+
+enum {
+  PROP_0,
+  PROP_TEXT,
+  PROP_EDITABLE,
+  N_PROPS
+};
+
+struct _GtkPathWidget
+{
+  GtkWidget parent_instance;
+
+  char *text;
+  gboolean editable;
+
+  graphene_point_t points[4];
+
+  guint active_point;
+
+  GskPath *line_path;
+  GskPath *text_path;
+
+  GdkPaintable *background;
+};
+
+struct _GtkPathWidgetClass
+{
+  GtkWidgetClass parent_class;
+};
+
+static GParamSpec *properties[N_PROPS] = { NULL, };
+
+G_DEFINE_TYPE (GtkPathWidget, gtk_path_widget, GTK_TYPE_WIDGET)
+
+static GskPath *
+create_path_from_text (GtkWidget  *widget,
+                       const char *text,
+                       graphene_point_t *out_offset)
+{
+  PangoLayout *layout;
+  PangoFontDescription *desc;
+  GskPathBuilder *builder;
+  GskPath *result;
+
+  layout = gtk_widget_create_pango_layout (widget, text);
+  desc = pango_font_description_from_string ("sans bold 36");
+  pango_layout_set_font_description (layout, desc);
+  pango_font_description_free (desc);
+
+  builder = gsk_path_builder_new ();
+  gsk_path_builder_add_layout (builder, layout);
+  result = gsk_path_builder_free_to_path (builder);
+
+  if (out_offset)
+    graphene_point_init (out_offset, 0, - pango_layout_get_baseline (layout) / (double) PANGO_SCALE);
+  g_object_unref (layout);
+
+  return result;
+}
+
+typedef struct
+{
+  GskPathMeasure *measure;
+  GskPathBuilder *builder;
+  graphene_point_t offset;
+  double scale;
+} GtkPathTransform;
+
+static void
+gtk_path_transform_point (GskPathMeasure         *measure,
+                          const graphene_point_t *pt,
+                          const graphene_point_t *offset,
+                          float                   scale,
+                          graphene_point_t       *res)
+{
+  graphene_vec2_t tangent;
+  GskPathPoint point;
+
+  if (gsk_path_measure_get_point (measure, (pt->x + offset->x) * scale, &point))
+    {
+      GskPath *path = gsk_path_measure_get_path (measure);
+
+      gsk_path_point_get_position (&point, path, res);
+      gsk_path_point_get_tangent (&point, path, GSK_PATH_TO_END, &tangent);
+
+      res->x -= (pt->y + offset->y) * scale * graphene_vec2_get_y (&tangent);
+      res->y += (pt->y + offset->y) * scale * graphene_vec2_get_x (&tangent);
+    }
+}
+
+static gboolean
+gtk_path_transform_op (GskPathOperation        op,
+                       const graphene_point_t *pts,
+                       gsize                   n_pts,
+                       float                   weight,
+                       gpointer                data)
+{
+  GtkPathTransform *transform = data;
+
+  switch (op)
+  {
+    case GSK_PATH_MOVE:
+      {
+        graphene_point_t res;
+        gtk_path_transform_point (transform->measure, &pts[0], &transform->offset, transform->scale, &res);
+        gsk_path_builder_move_to (transform->builder, res.x, res.y);
+      }
+      break;
+
+    case GSK_PATH_LINE:
+      {
+        graphene_point_t res;
+        gtk_path_transform_point (transform->measure, &pts[1], &transform->offset, transform->scale, &res);
+        gsk_path_builder_line_to (transform->builder, res.x, res.y);
+      }
+      break;
+
+    case GSK_PATH_QUAD:
+      {
+        graphene_point_t res[2];
+        gtk_path_transform_point (transform->measure, &pts[1], &transform->offset, transform->scale, &res[0]);
+        gtk_path_transform_point (transform->measure, &pts[2], &transform->offset, transform->scale, &res[1]);
+        gsk_path_builder_quad_to (transform->builder, res[0].x, res[0].y, res[1].x, res[1].y);
+      }
+      break;
+
+    case GSK_PATH_CUBIC:
+      {
+        graphene_point_t res[3];
+        gtk_path_transform_point (transform->measure, &pts[1], &transform->offset, transform->scale, &res[0]);
+        gtk_path_transform_point (transform->measure, &pts[2], &transform->offset, transform->scale, &res[1]);
+        gtk_path_transform_point (transform->measure, &pts[3], &transform->offset, transform->scale, &res[2]);
+        gsk_path_builder_cubic_to (transform->builder, res[0].x, res[0].y, res[1].x, res[1].y, res[2].x, res[2].y);
+      }
+      break;
+
+    case GSK_PATH_CONIC:
+      {
+        graphene_point_t res[2];
+        gtk_path_transform_point (transform->measure, &pts[1], &transform->offset, transform->scale, &res[0]);
+        gtk_path_transform_point (transform->measure, &pts[3], &transform->offset, transform->scale, &res[1]);
+        gsk_path_builder_conic_to (transform->builder, res[0].x, res[0].y, res[1].x, res[1].y, weight);
+      }
+      break;
+
+    case GSK_PATH_CLOSE:
+      gsk_path_builder_close (transform->builder);
+      break;
+
+    default:
+      g_assert_not_reached();
+      return FALSE;
+  }
+
+  return TRUE;
+}
+
+static GskPath *
+gtk_path_transform (GskPath                *line_path,
+                    GskPath                *path,
+                    const graphene_point_t *offset)
+{
+  GskPathMeasure *measure = gsk_path_measure_new (line_path);
+  GtkPathTransform transform = { measure, gsk_path_builder_new (), *offset };
+  graphene_rect_t bounds;
+
+  gsk_path_get_bounds (path, &bounds);
+  if (bounds.origin.x + bounds.size.width > 0)
+    transform.scale = gsk_path_measure_get_length (measure) / (bounds.origin.x + bounds.size.width);
+  else
+    transform.scale = 1.0f;
+
+  gsk_path_foreach (path, -1, gtk_path_transform_op, &transform);
+
+  gsk_path_measure_unref (measure);
+
+  return gsk_path_builder_free_to_path (transform.builder);
+}
+
+static void
+gtk_path_widget_clear_text_path (GtkPathWidget *self)
+{
+  g_clear_pointer (&self->text_path, gsk_path_unref);
+}
+
+static void
+gtk_path_widget_clear_paths (GtkPathWidget *self)
+{
+  gtk_path_widget_clear_text_path (self);
+
+  g_clear_pointer (&self->line_path, gsk_path_unref);
+}
+
+static void
+gtk_path_widget_create_text_path (GtkPathWidget *self)
+{
+  GskPath *path;
+  graphene_point_t offset;
+
+  gtk_path_widget_clear_text_path (self);
+
+  path = create_path_from_text (GTK_WIDGET (self), self->text, &offset);
+  self->text_path = gtk_path_transform (self->line_path, path, &offset);
+
+  gsk_path_unref (path);
+}
+
+static void
+gtk_path_widget_create_paths (GtkPathWidget *self)
+{
+  double width = gtk_widget_get_width (GTK_WIDGET (self));
+  double height = gtk_widget_get_height (GTK_WIDGET (self));
+  GskPathBuilder *builder;
+
+  gtk_path_widget_clear_paths (self);
+
+  if (width <= 0 || height <= 0)
+    return;
+
+  builder = gsk_path_builder_new ();
+  gsk_path_builder_move_to (builder,
+                            self->points[0].x * width, self->points[0].y * height);
+  gsk_path_builder_cubic_to (builder,
+                             self->points[1].x * width, self->points[1].y * height,
+                             self->points[2].x * width, self->points[2].y * height,
+                             self->points[3].x * width, self->points[3].y * height);
+  self->line_path = gsk_path_builder_free_to_path (builder);
+
+  gtk_path_widget_create_text_path (self);
+}
+
+static void
+gtk_path_widget_allocate (GtkWidget *widget,
+                          int        width,
+                          int        height,
+                          int        baseline)
+{
+  GtkPathWidget *self = GTK_PATH_WIDGET (widget);
+
+  GTK_WIDGET_CLASS (gtk_path_widget_parent_class)->size_allocate (widget, width, height, baseline);
+
+  gtk_path_widget_create_paths (self);
+}
+
+static void
+gtk_path_widget_snapshot (GtkWidget   *widget,
+                          GtkSnapshot *snapshot)
+{
+  GtkPathWidget *self = GTK_PATH_WIDGET (widget);
+  double width = gtk_widget_get_width (widget);
+  double height = gtk_widget_get_height (widget);
+  GskPath *path;
+  GskStroke *stroke;
+  gsize i;
+
+  /* frosted glass the background */
+  gtk_snapshot_push_blur (snapshot, 100);
+  gdk_paintable_snapshot (self->background, snapshot, width, height);
+  gtk_snapshot_append_color (snapshot, &(GdkRGBA) { 1, 1, 1, 0.6 }, &GRAPHENE_RECT_INIT (0, 0, width, height));
+  gtk_snapshot_pop (snapshot);
+
+  /* draw the text */
+  if (self->text_path)
+    {
+      gtk_snapshot_push_fill (snapshot, self->text_path, GSK_FILL_RULE_WINDING);
+      gdk_paintable_snapshot (self->background, snapshot, width, height);
+
+      /* ... with an emboss effect */
+      stroke = gsk_stroke_new (2.0);
+      gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT(1, 1));
+      gtk_snapshot_push_stroke (snapshot, self->text_path, stroke);
+      gtk_snapshot_append_color (snapshot, &(GdkRGBA) { 0, 0, 0, 0.2 }, &GRAPHENE_RECT_INIT (0, 0, width, height));
+      gsk_stroke_free (stroke);
+      gtk_snapshot_pop (snapshot);
+
+      gtk_snapshot_pop (snapshot);
+    }
+
+  if (self->editable && self->line_path)
+    {
+      GskPathBuilder *builder;
+
+      /* draw the control line */
+      stroke = gsk_stroke_new (1.0);
+      gtk_snapshot_push_stroke (snapshot, self->line_path, stroke);
+      gsk_stroke_free (stroke);
+      gtk_snapshot_append_color (snapshot, &(GdkRGBA) { 0, 0, 0, 1 }, &GRAPHENE_RECT_INIT (0, 0, width, height));
+      gtk_snapshot_pop (snapshot);
+
+      /* draw the points */
+      builder = gsk_path_builder_new ();
+      for (i = 0; i < 4; i++)
+        {
+          gsk_path_builder_add_circle (builder, &GRAPHENE_POINT_INIT (self->points[i].x * width, self->points[i].y * height), POINT_SIZE);
+        }
+      path = gsk_path_builder_free_to_path (builder);
+
+      gtk_snapshot_push_fill (snapshot, path, GSK_FILL_RULE_WINDING);
+      gtk_snapshot_append_color (snapshot, &(GdkRGBA) { 1, 1, 1, 1 }, &GRAPHENE_RECT_INIT (0, 0, width, height));
+      gtk_snapshot_pop (snapshot);
+
+      stroke = gsk_stroke_new (1.0);
+      gtk_snapshot_push_stroke (snapshot, path, stroke);
+      gsk_stroke_free (stroke);
+      gtk_snapshot_append_color (snapshot, &(GdkRGBA) { 0, 0, 0, 1 }, &GRAPHENE_RECT_INIT (0, 0, width, height));
+      gtk_snapshot_pop (snapshot);
+
+      gsk_path_unref (path);
+    }
+}
+
+static void
+gtk_path_widget_set_text (GtkPathWidget *self,
+                          const char    *text)
+{
+  if (g_strcmp0 (self->text, text) == 0)
+    return;
+
+  g_free (self->text);
+  self->text = g_strdup (text);
+
+  gtk_path_widget_create_paths (self);
+
+  gtk_widget_queue_draw (GTK_WIDGET (self));
+
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_TEXT]);
+}
+
+static void
+gtk_path_widget_set_editable (GtkPathWidget *self,
+                              gboolean       editable)
+{
+  if (self->editable == editable)
+    return;
+
+  self->editable = editable;
+
+  gtk_widget_queue_draw (GTK_WIDGET (self));
+
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_EDITABLE]);
+}
+
+static void
+gtk_path_widget_set_property (GObject      *object,
+                              guint         prop_id,
+                              const GValue *value,
+                              GParamSpec   *pspec)
+
+{
+  GtkPathWidget *self = GTK_PATH_WIDGET (object);
+
+  switch (prop_id)
+    {
+    case PROP_TEXT:
+      gtk_path_widget_set_text (self, g_value_get_string (value));
+      break;
+
+    case PROP_EDITABLE:
+      gtk_path_widget_set_editable (self, g_value_get_boolean (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_path_widget_get_property (GObject    *object,
+                              guint       prop_id,
+                              GValue     *value,
+                              GParamSpec *pspec)
+{
+  GtkPathWidget *self = GTK_PATH_WIDGET (object);
+
+  switch (prop_id)
+    {
+    case PROP_TEXT:
+      g_value_set_string (value, self->text);
+      break;
+
+    case PROP_EDITABLE:
+      g_value_set_boolean (value, self->editable);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_path_widget_dispose (GObject *object)
+{
+  GtkPathWidget *self = GTK_PATH_WIDGET (object);
+
+  gtk_path_widget_clear_paths (self);
+
+  G_OBJECT_CLASS (gtk_path_widget_parent_class)->dispose (object);
+}
+
+static void
+gtk_path_widget_class_init (GtkPathWidgetClass *klass)
+{
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = gtk_path_widget_dispose;
+  object_class->set_property = gtk_path_widget_set_property;
+  object_class->get_property = gtk_path_widget_get_property;
+
+  widget_class->size_allocate = gtk_path_widget_allocate;
+  widget_class->snapshot = gtk_path_widget_snapshot;
+
+  properties[PROP_TEXT] =
+    g_param_spec_string ("text",
+                         "text",
+                         "Text transformed along a path",
+                         NULL,
+                         G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
+
+  properties[PROP_EDITABLE] =
+    g_param_spec_boolean ("editable",
+                          "editable",
+                          "If the path can be edited by the user",
+                          FALSE,
+                          G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
+
+  g_object_class_install_properties (object_class, N_PROPS, properties);
+}
+
+static void
+drag_begin (GtkGestureDrag *gesture,
+            double          x,
+            double          y,
+            GtkPathWidget  *self)
+{
+  graphene_point_t mouse = GRAPHENE_POINT_INIT (x, y);
+  double width = gtk_widget_get_width (GTK_WIDGET (self));
+  double height = gtk_widget_get_height (GTK_WIDGET (self));
+  gsize i;
+
+  for (i = 0; i < 4; i++)
+    {
+      if (graphene_point_distance (&GRAPHENE_POINT_INIT (self->points[i].x * width, self->points[i].y * height), &mouse, NULL, NULL) <= POINT_SIZE)
+        {
+          self->active_point = i;
+          break;
+        }
+    }
+  if (i == 4)
+    {
+      gtk_gesture_set_state (GTK_GESTURE (gesture), GTK_EVENT_SEQUENCE_DENIED);
+      return;
+    }
+
+  gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+drag_update (GtkGestureDrag *drag,
+             double          offset_x,
+             double          offset_y,
+             GtkPathWidget  *self)
+{
+  double width = gtk_widget_get_width (GTK_WIDGET (self));
+  double height = gtk_widget_get_height (GTK_WIDGET (self));
+  double start_x, start_y;
+
+  gtk_gesture_drag_get_start_point (drag, &start_x, &start_y);
+
+  self->points[self->active_point] = GRAPHENE_POINT_INIT ((start_x + offset_x) / width,
+                                                          (start_y + offset_y) / height);
+  self->points[self->active_point].x = CLAMP (self->points[self->active_point].x, 0, 1);
+  self->points[self->active_point].y = CLAMP (self->points[self->active_point].y, 0, 1);
+
+  gtk_path_widget_create_paths (self);
+
+  gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+pointer_motion (GtkEventControllerMotion *controller,
+                double                    x,
+                double                    y,
+                GtkPathWidget            *self)
+{
+  GskPathPoint point;
+
+  if (gsk_path_get_closest_point (self->line_path,
+                                  &GRAPHENE_POINT_INIT (x, y),
+                                  INFINITY,
+                                  &point,
+                                  NULL))
+    {
+      gtk_widget_queue_draw (GTK_WIDGET (self));
+    }
+}
+
+static void
+pointer_leave (GtkEventControllerMotion *controller,
+               GtkPathWidget            *self)
+{
+  gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+gtk_path_widget_init (GtkPathWidget *self)
+{
+  GtkEventController *controller;
+
+  controller = GTK_EVENT_CONTROLLER (gtk_gesture_drag_new ());
+  g_signal_connect (controller, "drag-begin", G_CALLBACK (drag_begin), self);
+  g_signal_connect (controller, "drag-update", G_CALLBACK (drag_update), self);
+  g_signal_connect (controller, "drag-end", G_CALLBACK (drag_update), self);
+  gtk_widget_add_controller (GTK_WIDGET (self), controller);
+
+  controller = GTK_EVENT_CONTROLLER (gtk_event_controller_motion_new ());
+  g_signal_connect (controller, "enter", G_CALLBACK (pointer_motion), self);
+  g_signal_connect (controller, "motion", G_CALLBACK (pointer_motion), self);
+  g_signal_connect (controller, "leave", G_CALLBACK (pointer_leave), self);
+  gtk_widget_add_controller (GTK_WIDGET (self), controller);
+
+  self->points[0] = GRAPHENE_POINT_INIT (0.1, 0.9);
+  self->points[1] = GRAPHENE_POINT_INIT (0.3, 0.1);
+  self->points[2] = GRAPHENE_POINT_INIT (0.7, 0.1);
+  self->points[3] = GRAPHENE_POINT_INIT (0.9, 0.9);
+
+  self->background = GDK_PAINTABLE (gdk_texture_new_from_resource ("/sliding_puzzle/portland-rose.jpg"));
+
+  gtk_path_widget_set_text (self, "It's almost working");
+}
+
+GtkWidget *
+gtk_path_widget_new (void)
+{
+  GtkPathWidget *self;
+
+  self = g_object_new (GTK_TYPE_PATH_WIDGET, NULL);
+
+  return GTK_WIDGET (self);
+}
+
+GtkWidget *
+do_path_text (GtkWidget *do_widget)
+{
+  static GtkWidget *window = NULL;
+
+  if (!window)
+    {
+      GtkBuilder *builder;
+
+      g_type_ensure (GTK_TYPE_PATH_WIDGET);
+
+      builder = gtk_builder_new_from_resource ("/path_text/path_text.ui");
+      window = GTK_WIDGET (gtk_builder_get_object (builder, "window"));
+      gtk_window_set_display (GTK_WINDOW (window),
+                              gtk_widget_get_display (do_widget));
+      g_object_add_weak_pointer (G_OBJECT (window), (gpointer *) &window);
+      g_object_unref (builder);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_window_present (GTK_WINDOW (window));
+  else
+    gtk_window_destroy (GTK_WINDOW (window));
+
+  return window;
+}

demos/gtk-demo/path_text.ui

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <object class="GtkWindow" id="window">
+    <property name="title" translatable="yes">Text along a Path</property>
+    <child type="titlebar">
+      <object class="GtkHeaderBar">
+        <child type="end">
+          <object class="GtkToggleButton" id="edit-toggle">
+            <property name="icon-name">document-edit-symbolic</property>
+          </object>
+        </child>
+      </object>
+    </child>
+    <child>
+      <object class="GtkBox">
+        <property name="orientation">vertical</property>
+        <child>
+          <object class="GtkRevealer">
+            <property name="reveal-child" bind-source="edit-toggle" bind-property="active" bind-flags="sync-create"></property>
+            <child>
+              <object class="GtkEntry" id="text">
+                <property name="text">Through the looking glass</property>
+              </object>
+            </child>
+          </object>
+        </child>
+        <child>
+          <object class="GtkPathWidget" id="view">
+            <property name="editable" bind-source="edit-toggle" bind-property="active" bind-flags="sync-create"></property>
+            <property name="text" bind-source="text" bind-property="text" bind-flags="sync-create"></property>
+            <property name="hexpand">true</property>
+            <property name="vexpand">true</property>
+          </object>
+        </child>
+      </object>
+    </child>
+  </object>
+</interface>

demos/gtk-demo/path_walk.c

@@ -0,0 +1,373 @@
+/* Path/Walk
+ *
+ * This demo draws a world map and shows how to animate objects along a GskPath.
+ *
+ * The world map that is used here is a path with 211 lines and 1569 cubic
+ * Bėzier segments in 121 contours.
+ */
+
+#include <glib/gi18n.h>
+#include <gtk/gtk.h>
+
+#define GTK_TYPE_PATH_WALK (gtk_path_walk_get_type ())
+G_DECLARE_FINAL_TYPE (GtkPathWalk, gtk_path_walk, GTK, PATH_WALK, GtkWidget)
+
+#define POINT_SIZE 8
+
+enum {
+  PROP_0,
+  PROP_N_POINTS,
+  PROP_PATH,
+  N_PROPS
+};
+
+struct _GtkPathWalk
+{
+  GtkWidget parent_instance;
+
+  GskPath *path;
+  GskPathMeasure *measure;
+  graphene_rect_t bounds;
+  GskPath *arrow_path;
+  guint n_points;
+};
+
+struct _GtkPathWalkClass
+{
+  GtkWidgetClass parent_class;
+};
+
+static GParamSpec *properties[N_PROPS] = { NULL, };
+
+G_DEFINE_TYPE (GtkPathWalk, gtk_path_walk, GTK_TYPE_WIDGET)
+
+static void
+rgba_init_from_hsla (GdkRGBA *rgba,
+                     float    hue,
+                     float    saturation,
+                     float    lightness,
+                     float    alpha)
+{
+  float m1, m2;
+
+  if (lightness <= 0.5)
+    m2 = lightness * (1 + saturation);
+  else
+    m2 = lightness + saturation - lightness * saturation;
+  m1 = 2 * lightness - m2;
+
+  rgba->alpha = alpha;
+
+  if (saturation == 0)
+    {
+      rgba->red = lightness;
+      rgba->green = lightness;
+      rgba->blue = lightness;
+    }
+  else
+    {
+      hue = hue + 120;
+      while (hue > 360)
+        hue -= 360;
+      while (hue < 0)
+        hue += 360;
+
+      if (hue < 60)
+        rgba->red = m1 + (m2 - m1) * hue / 60;
+      else if (hue < 180)
+        rgba->red = m2;
+      else if (hue < 240)
+        rgba->red = m1 + (m2 - m1) * (240 - hue) / 60;
+      else
+        rgba->red = m1;
+
+      hue -= 120;
+      if (hue < 0)
+        hue += 360;
+
+      if (hue < 60)
+        rgba->green = m1 + (m2 - m1) * hue / 60;
+      else if (hue < 180)
+        rgba->green = m2;
+      else if (hue < 240)
+        rgba->green = m1 + (m2 - m1) * (240 - hue) / 60;
+      else
+        rgba->green = m1;
+
+      hue -= 120;
+      if (hue < 0)
+        hue += 360;
+
+      if (hue < 60)
+        rgba->blue = m1 + (m2 - m1) * hue / 60;
+      else if (hue < 180)
+        rgba->blue = m2;
+      else if (hue < 240)
+        rgba->blue = m1 + (m2 - m1) * (240 - hue) / 60;
+      else
+        rgba->blue = m1;
+    }
+}
+
+static void
+gtk_path_walk_snapshot (GtkWidget   *widget,
+                        GtkSnapshot *snapshot)
+{
+  GtkPathWalk *self = GTK_PATH_WALK (widget);
+  double width = gtk_widget_get_width (widget);
+  double height = gtk_widget_get_height (widget);
+  float length, progress;
+  GskStroke *stroke;
+  guint i;
+
+  if (self->path == NULL)
+    return;
+
+  gtk_snapshot_save (snapshot);
+
+  stroke = gsk_stroke_new (2.0);
+  gtk_snapshot_push_stroke (snapshot, self->path, stroke);
+  gtk_snapshot_append_color (snapshot, &(GdkRGBA) { 0, 0, 0, 1 }, &GRAPHENE_RECT_INIT (0, 0, width, height));
+  gtk_snapshot_pop (snapshot);
+  gsk_stroke_free (stroke);
+
+  length = gsk_path_measure_get_length (self->measure);
+  progress = 25.f * gdk_frame_clock_get_frame_time (gtk_widget_get_frame_clock (widget)) / G_USEC_PER_SEC;
+
+  stroke = gsk_stroke_new (1.0);
+  for (i = 0; i < self->n_points; i++)
+    {
+      GskPathPoint point;
+      graphene_point_t position;
+      float angle;
+      GdkRGBA color;
+      float distance;
+
+      distance = i * length / self->n_points;
+      distance = fmod (distance + progress, length);
+
+      gsk_path_measure_get_point (self->measure, distance, &point);
+      gsk_path_point_get_position (&point, self->path, &position);
+      angle = gsk_path_point_get_rotation (&point, self->path, GSK_PATH_FROM_START);
+      rgba_init_from_hsla (&color, 360.f * i / self->n_points, 1, 0.5, 1);
+
+      gtk_snapshot_save (snapshot);
+      gtk_snapshot_translate (snapshot, &position);
+      gtk_snapshot_rotate (snapshot, angle);
+      gtk_snapshot_append_fill (snapshot, self->arrow_path, GSK_FILL_RULE_EVEN_ODD, &color);
+      gtk_snapshot_append_stroke (snapshot, self->arrow_path, stroke, &(GdkRGBA) { 0, 0, 0, 1 });
+      gtk_snapshot_restore (snapshot);
+    }
+
+  gsk_stroke_free (stroke);
+  gtk_snapshot_restore (snapshot);
+}
+
+static void
+gtk_path_walk_measure (GtkWidget      *widget,
+                       GtkOrientation  orientation,
+                       int             for_size,
+                       int            *minimum,
+                       int            *natural,
+                       int            *minimum_baseline,
+                       int            *natural_baseline)
+{
+  GtkPathWalk *self = GTK_PATH_WALK (widget);
+
+  if (orientation == GTK_ORIENTATION_HORIZONTAL)
+    *minimum = *natural = (int) ceilf (self->bounds.size.width);
+  else
+    *minimum = *natural = (int) ceilf (self->bounds.size.height);
+}
+
+static void
+gtk_path_walk_set_n_points (GtkPathWalk *self,
+                            gsize        n_points)
+{
+  if (self->n_points == n_points)
+    return;
+
+  self->n_points = n_points;
+
+  gtk_widget_queue_draw (GTK_WIDGET (self));
+
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_N_POINTS]);
+}
+
+static void
+gtk_path_walk_set_path (GtkPathWalk *self,
+                        GskPath     *path)
+{
+  if (self->path == path)
+    return;
+
+  g_clear_pointer (&self->path, gsk_path_unref);
+  graphene_rect_init (&self->bounds, 0, 0, 0, 0);
+  if (path)
+    {
+      GskStroke *stroke;
+
+      self->path = gsk_path_ref (path);
+      stroke = gsk_stroke_new (2.0);
+      gsk_path_get_stroke_bounds (path, stroke, &self->bounds);
+      gsk_stroke_free (stroke);
+      self->measure = gsk_path_measure_new (self->path);
+    }
+
+  gtk_widget_queue_resize (GTK_WIDGET (self));
+
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_PATH]);
+}
+
+static void
+gtk_path_walk_set_property (GObject      *object,
+                            guint         prop_id,
+                            const GValue *value,
+                            GParamSpec   *pspec)
+
+{
+  GtkPathWalk *self = GTK_PATH_WALK (object);
+
+  switch (prop_id)
+    {
+    case PROP_N_POINTS:
+      gtk_path_walk_set_n_points (self, g_value_get_uint (value));
+      break;
+
+    case PROP_PATH:
+      gtk_path_walk_set_path (self, g_value_get_boxed (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_path_walk_get_property (GObject    *object,
+                            guint       prop_id,
+                            GValue     *value,
+                            GParamSpec *pspec)
+{
+  GtkPathWalk *self = GTK_PATH_WALK (object);
+
+  switch (prop_id)
+    {
+    case PROP_N_POINTS:
+      g_value_set_uint (value, self->n_points);
+      break;
+
+    case PROP_PATH:
+      g_value_set_boxed (value, self->path);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_path_walk_dispose (GObject *object)
+{
+  GtkPathWalk *self = GTK_PATH_WALK (object);
+
+  g_clear_pointer (&self->path, gsk_path_unref);
+  g_clear_pointer (&self->measure, gsk_path_measure_unref);
+  g_clear_pointer (&self->arrow_path, gsk_path_unref);
+
+  G_OBJECT_CLASS (gtk_path_walk_parent_class)->dispose (object);
+}
+
+static void
+gtk_path_walk_class_init (GtkPathWalkClass *klass)
+{
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = gtk_path_walk_dispose;
+  object_class->set_property = gtk_path_walk_set_property;
+  object_class->get_property = gtk_path_walk_get_property;
+
+  widget_class->snapshot = gtk_path_walk_snapshot;
+  widget_class->measure = gtk_path_walk_measure;
+
+  properties[PROP_N_POINTS] =
+    g_param_spec_uint ("n-points",
+                       NULL, NULL,
+                       1, G_MAXUINT,
+                       500,
+                       G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
+
+  properties[PROP_PATH] =
+    g_param_spec_boxed ("path",
+                        NULL, NULL,
+                        GSK_TYPE_PATH,
+                        G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
+
+  g_object_class_install_properties (object_class, N_PROPS, properties);
+}
+
+static gboolean
+tick_tick_tick (GtkWidget     *self,
+                GdkFrameClock *frame_clock,
+                gpointer       unused)
+{
+  gtk_widget_queue_draw (GTK_WIDGET (self));
+
+  return G_SOURCE_CONTINUE;
+}
+
+static void
+gtk_path_walk_init (GtkPathWalk *self)
+{
+  /* Data taken from
+   * https://commons.wikimedia.org/wiki/Maps_of_the_world#/media/File:Simplified_blank_world_map_without_Antartica_(no_borders).svg
+   */
+  GBytes *data = g_resources_lookup_data ("/path_walk/path_world.txt", 0, NULL);
+  GskPath *path = gsk_path_parse (g_bytes_get_data (data, NULL));
+  g_bytes_unref (data);
+  gtk_path_walk_set_path (self, path);
+  gsk_path_unref (path);
+  self->arrow_path = gsk_path_parse ("M 5 0 L 0 -5. 0 -2, -5 -2, -5 2, 0 2, 0 5 Z");
+  self->n_points = 500;
+  gtk_widget_add_tick_callback (GTK_WIDGET (self), tick_tick_tick, NULL, NULL);
+}
+
+GtkWidget *
+gtk_path_walk_new (void)
+{
+  GtkPathWalk *self;
+
+  self = g_object_new (GTK_TYPE_PATH_WALK, NULL);
+
+  return GTK_WIDGET (self);
+}
+
+GtkWidget *
+do_path_walk (GtkWidget *do_widget)
+{
+  static GtkWidget *window = NULL;
+
+  if (!window)
+    {
+      GtkBuilder *builder;
+
+      g_type_ensure (GTK_TYPE_PATH_WALK);
+
+      builder = gtk_builder_new_from_resource ("/path_walk/path_walk.ui");
+      window = GTK_WIDGET (gtk_builder_get_object (builder, "window"));
+      gtk_window_set_display (GTK_WINDOW (window),
+                              gtk_widget_get_display (do_widget));
+      g_object_add_weak_pointer (G_OBJECT (window), (gpointer *) &window);
+      g_object_unref (builder);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_window_present (GTK_WINDOW (window));
+  else
+    gtk_window_destroy (GTK_WINDOW (window));
+
+  return window;
+}

demos/gtk-demo/path_walk.ui

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <object class="GtkWindow" id="window">
+    <property name="title" translatable="yes">World Map</property>
+    <property name="titlebar">
+      <object class="GtkHeaderBar">
+        <child type="end">
+          <object class="GtkSpinButton">
+            <property name="adjustment">
+              <object class="GtkAdjustment" id="adjustment">
+                <property name="lower">0</property>
+                <property name="upper">5000</property>
+                <property name="value">500</property>
+              </object>
+            </property>
+          </object>
+        </child>
+      </object>
+    </property>
+    <property name="child">
+      <object class="GtkBox">
+        <property name="orientation">vertical</property>
+        <child>
+          <object class="GtkPathWalk" id="view">
+            <property name="n-points" bind-source="adjustment" bind-property="value"/>
+            <property name="hexpand">true</property>
+            <property name="vexpand">true</property>
+          </object>
+        </child>
+      </object>
+    </property>
+  </object>
+</interface>

demos/node-editor/node-format.md

@@ -147,6 +147,19 @@ Creates a node like `gsk_cross_fade_node_new()` with the given properties.
 
 Creates a node like `gsk_debug_node_new()` with the given properties.
 
+### fill
+
+| property  | syntax          | default                | printed     |
+| --------- | --------------- | ---------------------- | ----------- |
+| child     | `<node>`        | *see below*            | always      |
+| path      | `<string>`      | ""                     | always      |
+| fill-rule | `<fill-rule>`   | winding                | always      |
+
+Creates a node like `gsk_fill_node_new()` with the given properties.
+
+The default child node is the default color node, but created with the
+bounds of the path.
+
 ### glshader
 
 | property   | syntax             | default                | printed     |
@@ -289,6 +302,24 @@ Creates a node like `gsk_rounded_clip_node_new()` with the given properties.
 
 Creates a node like `gsk_shadow_node_new()` with the given properties.
 
+### stroke
+
+| property    | syntax             | default           | printed     |
+| ----------- | ------------------ | ----------------- | ----------- |
+| child       | `<node>`           | *see below*       | always      |
+| path        | `<string>`         | ""                | always      |
+| line-width  | `<number>`         | 0                 | non-default |
+| line-cap    | `<line-cap>`       | butt              | always      |
+| line-join   | `<line-join>`      | miter             | always      |
+| miter-limit | `<number>`         | 4                 | non-default |
+| dash        | `<number>{+}|none` | none              | non-default |
+| dash-offset | `<number>`         | 0                 | non-default |
+
+Creates a node like `gsk_stroke_node_new()` with the given properties.
+
+The default child node is the default color node, but created with the
+stroke bounds of the path.
+
 ### text
 
 | property | syntax           | default                | printed     |

docs/reference/gsk/gsk4.toml.in

@@ -32,7 +32,34 @@ show_class_hierarchy = true
 base_url = "https://gitlab.gnome.org/GNOME/gtk/-/blob/main/"
 
 [extra]
+content_files = [
+  "paths.md",
+]
 content_images = [
   "gtk-logo.svg",
+  "images/arc-dark.png",
+  "images/arc-light.png",
+  "images/caps-dark.png",
+  "images/caps-light.png",
+  "images/conic-light.png",
+  "images/conic-dark.png",
+  "images/cubic-dark.png",
+  "images/cubic-light.png",
+  "images/curvature-dark.png",
+  "images/curvature-light.png",
+  "images/directions-dark.png",
+  "images/directions-light.png",
+  "images/fill-even-odd.png",
+  "images/fill-winding.png",
+  "images/join-dark.png",
+  "images/join-light.png",
+  "images/line-dark.png",
+  "images/line-light.png",
+  "images/path-dark.png",
+  "images/path-light.png",
+  "images/quad-dark.png",
+  "images/quad-light.png",
+  "images/stroke-miter.png",
+  "images/stroke-round.png",
 ]
 urlmap_file = "urlmap.js"

docs/reference/gsk/images/arc.svg

@@ -0,0 +1,92 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   width="210mm"
+   height="297mm"
+   viewBox="0 0 210 297"
+   version="1.1"
+   id="svg1"
+   inkscape:version="1.3 (0e150ed6c4, 2023-07-21)"
+   sodipodi:docname="arcto.svg"
+   inkscape:export-filename="cubic-light.png"
+   inkscape:export-xdpi="96"
+   inkscape:export-ydpi="96"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg">
+  <sodipodi:namedview
+     id="namedview1"
+     pagecolor="#ffffff"
+     bordercolor="#000000"
+     borderopacity="0.25"
+     inkscape:showpageshadow="2"
+     inkscape:pageopacity="0.0"
+     inkscape:pagecheckerboard="0"
+     inkscape:deskcolor="#d1d1d1"
+     inkscape:document-units="mm"
+     inkscape:zoom="0.75989759"
+     inkscape:cx="399.39592"
+     inkscape:cy="466.51023"
+     inkscape:window-width="1920"
+     inkscape:window-height="1123"
+     inkscape:window-x="0"
+     inkscape:window-y="0"
+     inkscape:window-maximized="1"
+     inkscape:current-layer="layer1"
+     showgrid="false" />
+  <defs
+     id="defs1" />
+  <g
+     inkscape:label="Layer 1"
+     inkscape:groupmode="layer"
+     id="layer1">
+    <path
+       style="fill:none;stroke:#000000;stroke-width:1;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none"
+       d="M 58.033485,123.96862 C 75.231194,113.95411 92.489919,103.26728 107.81401,113.89786"
+       id="path3"
+       sodipodi:nodetypes="cc" />
+    <ellipse
+       style="fill:none;stroke:#000000;stroke-width:0.20061772;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none"
+       id="path2"
+       cx="-16.837238"
+       cy="154.55043"
+       rx="35.832706"
+       ry="17.920988"
+       transform="matrix(0.86643544,-0.49928912,0.59215321,0.8058254,0,0)" />
+    <path
+       style="fill:none;stroke:#000000;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none"
+       d="M 57.432798,124.38759 86.59638,102.1496 107.25717,113.71009"
+       id="path1"
+       sodipodi:nodetypes="ccc" />
+    <circle
+       style="fill:#ff0404;fill-opacity:1;stroke:#000064;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none"
+       id="path2-8-7-9"
+       cx="86.580566"
+       cy="102.81618"
+       r="1.5" />
+    <path
+       style="fill:#f90048;stroke:#a2a2a2;stroke-width:1;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none;stroke-opacity:1"
+       d="m 45.061871,134.70541 12.60825,-10.20893"
+       id="path4-4"
+       sodipodi:nodetypes="cc" />
+    <path
+       style="fill:#f90048;stroke:#a2a2a2;stroke-width:1;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:1, 3;stroke-dashoffset:0;stroke-opacity:1"
+       d="m 35.405008,142.35717 8.95641,-7.26298"
+       id="path4-8-8"
+       sodipodi:nodetypes="cc" />
+    <circle
+       style="fill:#818181;fill-opacity:1;stroke:#000064;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none"
+       id="path2-8-7-61-1"
+       cx="57.597607"
+       cy="124.23325"
+       r="1.5" />
+    <circle
+       style="fill:#ff0404;fill-opacity:1;stroke:#000064;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none"
+       id="path2-8-7-6-5"
+       cx="108.01463"
+       cy="114.17829"
+       r="1.5" />
+  </g>
+</svg>

docs/reference/gsk/images/caps.svg

@@ -0,0 +1,81 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   width="210mm"
+   height="297mm"
+   viewBox="0 0 210 297"
+   version="1.1"
+   id="svg1"
+   inkscape:version="1.3 (0e150ed6c4, 2023-07-21)"
+   sodipodi:docname="caps.svg"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg">
+  <sodipodi:namedview
+     id="namedview1"
+     pagecolor="#ffffff"
+     bordercolor="#000000"
+     borderopacity="0.25"
+     inkscape:showpageshadow="2"
+     inkscape:pageopacity="0.0"
+     inkscape:pagecheckerboard="0"
+     inkscape:deskcolor="#d1d1d1"
+     inkscape:document-units="mm"
+     inkscape:zoom="2.1493149"
+     inkscape:cx="438.74445"
+     inkscape:cy="288.69664"
+     inkscape:window-width="1920"
+     inkscape:window-height="1123"
+     inkscape:window-x="0"
+     inkscape:window-y="0"
+     inkscape:window-maximized="1"
+     inkscape:current-layer="layer1" />
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docs/reference/gsk/images/conic.svg

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docs/reference/gsk/images/curvature.svg

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docs/reference/gsk/images/directions.svg

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docs/reference/gsk/images/join.svg

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docs/reference/gsk/images/line.svg

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docs/reference/gsk/images/path.svg

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+     inkscape:window-maximized="1"
+     inkscape:current-layer="layer1" />
+  <defs
+     id="defs1" />
+  <g
+     inkscape:label="Layer 1"
+     inkscape:groupmode="layer"
+     id="layer1">
+    <path
+       style="fill:none;fill-opacity:1;stroke:#000000;stroke-width:1;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none;stroke-opacity:1"
+       d="M 128.28233,149.47912 154.23127,90.244656 86.340809,68.820468"
+       id="path3" />
+    <path
+       style="fill:none;stroke:#000000;stroke-width:1;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;fill-opacity:1;stroke-dasharray:none;stroke-opacity:1"
+       d="m 33.956804,113.31099 c -9.049189,-11.90893 5.40551,-40.570358 20.351208,-39.990271 26.687501,1.035822 4.06495,71.984581 30.695656,74.009711 19.642072,1.49368 41.962402,-34.42048 30.634382,-50.536241 C 99.663884,74.068616 50.763019,135.42833 33.956804,113.31099 Z"
+       id="path1"
+       sodipodi:nodetypes="sssss" />
+    <circle
+       style="fill:#ff0404;fill-opacity:1;stroke:#000000;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none;stroke-opacity:1"
+       id="path2"
+       cx="34.517788"
+       cy="113.66589"
+       r="1.5" />
+    <circle
+       style="fill:#ff0404;fill-opacity:1;stroke:#000064;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none"
+       id="path2-8"
+       cx="55.045853"
+       cy="73.566689"
+       r="1.5" />
+    <circle
+       style="fill:#ff0404;fill-opacity:1;stroke:#000064;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none"
+       id="path2-8-5"
+       cx="55.045834"
+       cy="73.831245"
+       r="1.5" />
+    <circle
+       style="fill:#ff0404;fill-opacity:1;stroke:#000000;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none;stroke-opacity:1"
+       id="path2-8-9"
+       cx="55.045834"
+       cy="73.831245"
+       r="1.5" />
+    <circle
+       style="fill:#ff0404;fill-opacity:1;stroke:#000000;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none;stroke-opacity:1"
+       id="path2-8-9-7"
+       cx="86.398613"
+       cy="68.897667"
+       r="1.5" />
+    <circle
+       style="fill:#ff0404;fill-opacity:1;stroke:#000000;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none;stroke-opacity:1"
+       id="path2-8-9-7-8"
+       cx="153.87553"
+       cy="90.112595"
+       r="1.5" />
+    <circle
+       style="fill:#ff0404;fill-opacity:1;stroke:#000064;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none"
+       id="path2-8-7"
+       cx="84.803238"
+       cy="147.51736"
+       r="1.5" />
+    <circle
+       style="fill:#ff0404;fill-opacity:1;stroke:#000000;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none;stroke-opacity:1"
+       id="path2-8-7-2"
+       cx="115.28235"
+       cy="96.705284"
+       r="1.5" />
+    <circle
+       style="fill:#ff0404;fill-opacity:1;stroke:#000000;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none;stroke-opacity:1"
+       id="path2-8-9-7-9"
+       cx="127.92362"
+       cy="150.03427"
+       r="1.5" />
+  </g>
+</svg>

docs/reference/gsk/images/quad.svg

@@ -0,0 +1,83 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   width="210mm"
+   height="297mm"
+   viewBox="0 0 210 297"
+   version="1.1"
+   id="svg1"
+   inkscape:version="1.3 (0e150ed6c4, 2023-07-21)"
+   sodipodi:docname="path.svg"
+   inkscape:export-filename="path-dark.png"
+   inkscape:export-xdpi="96"
+   inkscape:export-ydpi="96"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg">
+  <sodipodi:namedview
+     id="namedview1"
+     pagecolor="#ffffff"
+     bordercolor="#000000"
+     borderopacity="0.25"
+     inkscape:showpageshadow="2"
+     inkscape:pageopacity="0.0"
+     inkscape:pagecheckerboard="0"
+     inkscape:deskcolor="#d1d1d1"
+     inkscape:document-units="mm"
+     inkscape:zoom="0.75989759"
+     inkscape:cx="398.07996"
+     inkscape:cy="466.51023"
+     inkscape:window-width="1920"
+     inkscape:window-height="1123"
+     inkscape:window-x="0"
+     inkscape:window-y="0"
+     inkscape:window-maximized="1"
+     inkscape:current-layer="layer1"
+     showgrid="false" />
+  <defs
+     id="defs1" />
+  <g
+     inkscape:label="Layer 1"
+     inkscape:groupmode="layer"
+     id="layer1">
+    <path
+       style="fill:#f90048;stroke:#a2a2a2;stroke-width:1;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none;stroke-opacity:1"
+       d="m 52.936092,207.66575 12.60825,-10.20893"
+       id="path4"
+       sodipodi:nodetypes="cc" />
+    <path
+       style="fill:#f90048;stroke:#a2a2a2;stroke-width:1;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:1, 3;stroke-dashoffset:0;stroke-opacity:1"
+       d="m 43.279229,215.31751 8.95641,-7.26298"
+       id="path4-8"
+       sodipodi:nodetypes="cc" />
+    <path
+       style="fill:none;stroke:#000000;stroke-width:1;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none;stroke-opacity:1"
+       d="M 66.150275,196.9925 C 86.276878,182.17569 104.9512,180.54783 123.39945,192.39557"
+       id="path5"
+       sodipodi:nodetypes="cc" />
+    <circle
+       style="fill:#ff0404;fill-opacity:1;stroke:#000064;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none"
+       id="path2-8-7"
+       cx="95.69075"
+       cy="175.70657"
+       r="1.5" />
+    <circle
+       style="fill:#818181;fill-opacity:1;stroke:#000064;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none"
+       id="path2-8-7-61"
+       cx="65.471832"
+       cy="197.19359"
+       r="1.5" />
+    <circle
+       style="fill:#ff0404;fill-opacity:1;stroke:#000064;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none"
+       id="path2-8-7-6"
+       cx="123.73506"
+       cy="192.49165"
+       r="1.5" />
+    <path
+       style="fill:none;fill-opacity:1;stroke:#000000;stroke-width:0.2;stroke-linecap:square;stroke-linejoin:bevel;stroke-miterlimit:10;stroke-dasharray:none;stroke-opacity:1"
+       d="m 65.439496,197.17632 30.328009,-21.33704 28.506125,16.61621"
+       id="path6" />
+  </g>
+</svg>

docs/reference/gsk/meson.build

@@ -1,3 +1,7 @@
+gsk_expand_content_md_files = [
+  'paths.md',
+]
+
 if get_option('documentation')
   gsk4_toml = configure_file(
     input: 'gsk4.toml.in',
@@ -21,7 +25,7 @@ if get_option('documentation')
       '@INPUT1@',
     ],
     depends: [ gdk_gir[0] ],
-    depend_files: [ expand_content_md_files ],
+    depend_files: [ gsk_expand_content_md_files ],
     build_by_default: true,
     install: true,
     install_dir: docs_dir,

docs/reference/gsk/paths.md

@@ -0,0 +1,174 @@
+Title: Paths
+Slug: paths
+
+GSK provides a path API that can be used to render more complex
+shapes than lines or rounded rectangles. It is comparable to cairos
+[path API](https://www.cairographics.org/manual/cairo-Paths.html),
+with some notable differences.
+
+In general, a path consists of one or more connected **_contours_**,
+each of which may have multiple **_operations_**, and may or may not be closed.
+Operations can be straight lines or curves of various kinds. At the points
+where the operations connect, the path can have sharp turns.
+
+<figure>
+  <picture>
+    <source srcset="path-dark.png" media="(prefers-color-scheme: dark)">
+    <img alt="A path with multiple contours" src="path-light.png">
+  </picture>
+  <figcaption>A path with one closed, and one open contour</figcaption>
+</figure>
+
+The central object of the GSK path API is the immutable [struct@Gsk.Path]
+struct, which contains path data in compact form suitable for rendering.
+
+## Creating Paths
+
+Since `GskPath` is immutable, the auxiliary [struct@Gsk.PathBuilder] struct
+can be used to construct a path piece by piece. The pieces are specified with
+points, some of which will be on the path, while others are just **_control points_**
+that are used to influence the shape of the resulting path.
+
+<figure>
+  <picture>
+    <source srcset="cubic-dark.png" media="(prefers-color-scheme: dark)">
+    <img alt="An cubic Bézier" src="cubic-light.png">
+  </picture>
+  <figcaption>A cubic Bézier operation, with 2 control points</figcaption>
+</figure>
+
+The `GskPathBuilder` API has three distinct groups of functions:
+
+- Functions for building contours from individual operations, like [method@Gsk.PathBuilder.move_to],
+  [method@Gsk.PathBuilder.line_to], [method@Gsk.PathBuilder.cubic_to], [method@Gsk.PathBuilder.close]. `GskPathBuilder` maintains a **_current point_**, so these methods all
+  take one less points than necessary for the operation (e.g. `gsk_path_builder_line_to`
+  only takes a single point and draws a line from the current point to the new point).
+
+- Functions for adding complete contours, such as [method@Gsk.PathBuilder.add_rect],
+  [method@Gsk.PathBuilder.add_rounded_rect], [method@Gsk.PathBuilder.add_circle].
+
+- Adding parts of a preexisting path. Functions in this group include
+  [method@Gsk.PathBuilder.add_path] and [method@Gsk.PathBuilder.add_segment].
+
+When you are done with building a path, you can convert the accumulated path
+data into a `GskPath` struct with [method@Gsk.PathBuilder.free_to_path].
+
+A sometimes convenient alternative is to create a path from a serialized form,
+with [func@Gsk.Path.parse]. This function interprets strings in SVG path syntax,
+such as:
+
+    M 100 100 C 100 200 200 200 200 100 Z
+
+## Rendering with Paths
+
+There are two main ways to render with paths. The first is to **_fill_** the
+interior of a path with a color or more complex content, such as a gradient.
+GSK supports different ways of determining what part of the plane are interior
+to the path, which can be selected with a [enum@Gsk.FillRule] value.
+
+<figure>
+  <picture>
+    <img alt="A filled path" src="fill-winding.png">
+  </picture>
+  <figcaption>A path filled with GSK_FILL_RULE_WINDING</figcaption>
+</figure>
+
+<figure>
+  <picture>
+    <img alt="A filled path" src="fill-even-odd.png">
+  </picture>
+  <figcaption>The same path, filled with GSK_FILL_RULE_EVEN_ODD</figcaption>
+</figure>
+
+To fill a path, use [gtk_snapshot_append_fill()](../gtk4/method.Snapshot.append_fill.html)
+or the more general [gtk_snapshot_push_fill()](../gtk4/method.Snapshot.push_fill.html).
+
+Alternatively, a path can be **_stroked_**, which means to emulate drawing
+with an idealized pen along the path. The result of stroking a path is another
+path (the **_stroke path_**), which is then filled.
+
+The stroke operation can be influenced with the [struct@Gsk.Stroke] struct
+that collects various stroke parameters, such as the line width, the style
+of line joins and line caps, and a dash pattern.
+
+<figure>
+  <picture>
+    <img alt="A stroked path" src="stroke-miter.png">
+  </picture>
+  <figcaption>The same path, stroked with GSK_LINE_JOIN_MITER</figcaption>
+</figure>
+
+<figure>
+  <picture>
+    <img alt="A stroked path" src="stroke-round.png">
+  </picture>
+  <figcaption>The same path, stroked with GSK_LINE_JOIN_ROUND</figcaption>
+</figure>
+
+To stroke a path, use
+[gtk_snapshot_append_stroke()](../gtk4/method.Snapshot.append_stroke.html)
+or [gtk_snapshot_push_stroke()](../gtk4/method.Snapshot.push_stroke.html).
+
+## Hit testing
+
+When paths are rendered as part of an interactive interface, it is sometimes
+necessary to determine whether the mouse points is over the path. GSK provides
+[method@Gsk.Path.in_fill] for this purpose.
+
+## Path length
+
+An important property of paths is their **_length_**. Computing it efficiently
+requires caching, therefore GSK provides a separate [struct@Gsk.PathMeasure] object
+to deal with path lengths. After constructing a `GskPathMeasure` object for a path,
+it can be used to determine the length of the path with [method@Gsk.PathMeasure.get_length]
+and locate points at a given distance into the path with [method@Gsk.PathMeasure.get_point].
+
+## Other Path APIs
+
+Paths have uses beyond rendering, for example as trajectories in animations.
+In such uses, it is often important to access properties of paths, such as
+their tangents at certain points. GSK provides an abstract representation
+for points on a path in the form of the [struct@Gsk.PathPoint] struct.
+You can query properties of a path at certain point once you have a
+`GskPathPoint` representing that point.
+
+`GskPathPoint` structs can be compared for equality with [method@Gsk.PathPoint.equal]
+and ordered wrt. to which one comes first, using [method@Gsk.PathPoint.compare].
+
+To obtain a `GskPathPoint`, use [method@Gsk.Path.get_closest_point],
+[method@Gsk.Path.get_start_point], [method@Gsk.Path.get_end_point] or
+[method@Gsk.PathMeasure.get_point].
+
+To query properties of the path at a point, use [method@Gsk.PathPoint.get_position],
+[method@Gsk.PathPoint.get_tangent], [method@Gsk.PathPoint.get_rotation],
+[method@Gsk.PathPoint.get_curvature] and [method@Gsk.PathPoint.get_distance].
+
+Some of the properties can have different values for the path going into
+the point and the path leaving the point, typically at points where the
+path takes sharp turns. Examples for this are tangents (which can have up
+to 4 different values) and curvatures (which can have two different values).
+
+<figure>
+  <picture>
+    <source srcset="directions-dark.png" media="(prefers-color-scheme: dark)">
+    <img alt="Path Tangents" src="directions-light.png">
+  </picture>
+  <figcaption>Path Tangents</figcaption>
+</figure>
+
+## Going beyond GskPath
+
+Lots of powerful functionality can be implemented for paths:
+
+- Finding intersections
+- Offsetting curves
+- Turning stroke outlines into paths
+- Molding curves (making them pass through a given point)
+
+GSK does not provide API for all of these, but it does offer a way to get at
+the underlying Bézier curves, so you can implement such functionality yourself.
+You can use [method@Gsk.Path.foreach] to iterate over the operations of the
+path, and get the points needed to reconstruct or modify the path piece by piece.
+
+See e.g. the [Primer on Bézier curves](https://pomax.github.io/bezierinfo/)
+for inspiration of useful things to explore.

docs/reference/gtk/gtk4-path-tool.rst

@@ -0,0 +1,200 @@
+.. _gtk4-path-tool(1):
+
+=================
+gtk4-path-tool
+=================
+
+-----------------------
+GskPath Utility
+-----------------------
+
+SYNOPSIS
+--------
+|   **gtk4-path-tool** <COMMAND> [OPTIONS...] <PATH>
+|
+|   **gtk4-path-tool** decompose [OPTIONS...] <PATH>
+|   **gtk4-path-tool** show [OPTIONS...] <PATH>
+|   **gtk4-path-tool** render [OPTIONS...] <PATH>
+|   **gtk4-path-tool** reverse [OPTIONS...] <PATH>
+|   **gtk4-path-tool** info [OPTIONS...] <PATH>
+
+DESCRIPTION
+-----------
+
+``gtk4-path-tool`` can perform various tasks on paths. Paths are specified
+in SVG syntax, as strings like "M 100 100 C 100 200 200 200 200 100 Z".
+
+To read a path from a file, use a filename that starts with a '.' or a '/'.
+To read a path from stdin, use '-'.
+
+COMMANDS
+--------
+
+Decomposing
+^^^^^^^^^^^
+
+The ``decompose`` command approximates the path by one with simpler elements.
+When used without options, the curves of the path are approximated by line
+segments.
+
+``--allow-quad``
+
+  Allow quadratic Bézier curves to be used in the generated path.
+
+``--allow-cubic``
+
+  Allow cubic Bézier curves to be used in the generated path.
+
+``--allow-conic``
+
+  Allow conic Bézier curves to be used in the generated path.
+
+Showing
+^^^^^^^
+
+The ``show`` command displays the given path in a window. The interior
+of the path is filled.
+
+``--fill-rule=VALUE``
+
+  The fill rule that is used to determine what areas are inside the path.
+  The possible values are ``winding`` or ``even-odd``. The default is ``winding``.
+
+``--fg-color=COLOR``
+
+  The color that is used to fill the interior of the path or stroke the path.
+  If not specified, black is used.
+
+``--bg-color=COLOR``
+
+  The color that is used to render the background behind the path.
+  If not specified, white is used.
+
+``--fill``
+
+  Fill the path (this is the default).
+
+``--stroke``
+
+  Stroke the path instead of filling it.
+
+``--line-width=VALUE``
+
+  The line width to use for the stroke. ``VALUE`` must be a positive number.
+  The default line width is 1.
+
+``--line-cap=VALUE``
+
+  The cap style to use at line ends. The possible values are ``butt``, ``round``
+  or ``square``. See the SVG specification for details on these styles.
+  The default cap style is ``butt``.
+
+``--line-join=VALUE``
+
+  The join style to use at line joins. The possible values are ``miter``,
+  ``miter-clip``, ``round``, ``bevel`` or ``arcs``. See the SVG specification
+  for details on these styles.
+  The default join style is ``miter``.
+
+``--miter-limit=VALUE``
+
+  The limit at which to clip miters at line joins. The default value is 4.
+
+``--dashes=VALUE``
+
+  The dash pattern to use for this stroke. A dash pattern is specified by
+  a comma-separated list of alternating non-negative numbers. Each number
+  provides the length of alternate "on" and "off" portions of the stroke.
+  If the dash pattern is empty, dashing is disabled, which is the default.
+  See the SVG specification for details on dashing.
+
+``--dash-offset=VALUE``
+
+  The offset into the dash pattern where dashing should begin.
+  The default value is 0.
+
+Rendering
+^^^^^^^^^
+
+The ``render`` command renders the given path as a PNG image.
+The interior of the path is filled.
+
+``--fill-rule=VALUE``
+
+  The fill rule that is used to determine what areas are inside the path.
+  The possible values are ``winding`` or ``even-odd``. The default is ``winding``.
+
+``--fg-color=COLOR``
+
+  The color that is used to fill the interior of the path or stroke the path.
+  If not specified, black is used.
+
+``--bg-color=COLOR``
+
+  The color that is used to render the background behind the path.
+  If not specified, white is used.
+
+``--output-file=FILE``
+
+  The file to save the PNG image to.
+  If not specified, "path.png" is used.
+
+``--fill``
+
+  Fill the path (this is the default).
+
+``--stroke``
+
+  Stroke the path instead of filling it.
+
+``--line-width=VALUE``
+
+  The line width to use for the stroke. ``VALUE`` must be a positive number.
+  The default line width is 1.
+
+``--line-cap=VALUE``
+
+  The cap style to use at line ends. The possible values are ``butt``, ``round``
+  or ``square``. See the SVG specification for details on these styles.
+  The default cap style is ``butt``.
+
+``--line-join=VALUE``
+
+  The join style to use at line joins. The possible values are ``miter``,
+  ``miter-clip``, ``round``, ``bevel`` or ``arcs``. See the SVG specification
+  for details on these styles.
+  The default join style is ``miter``.
+
+``--miter-limit=VALUE``
+
+  The limit at which to clip miters at line joins. The default value is 4.
+
+``--dashes=VALUE``
+
+  The dash pattern to use for this stroke. A dash pattern is specified by
+  a comma-separated list of alternating non-negative numbers. Each number
+  provides the length of alternate "on" and "off" portions of the stroke.
+  If the dash pattern is empty, dashing is disabled, which is the default.
+  See the SVG specification for details on dashing.
+
+``--dash-offset=VALUE``
+
+  The offset into the dash pattern where dashing should begin.
+  The default value is 0.
+
+Reversing
+^^^^^^^^^
+
+The ``reverse`` command changes the direction of the path. The resulting
+paths starts where the original path ends.
+
+Info
+^^^^
+
+The ``info`` command shows various information about the given path,
+such as its bounding box.
+
+REFERENCES
+----------
+
+- SVG Path Specification, https://www.w3.org/TR/SVG2/paths.html

docs/reference/gtk/meson.build

@@ -77,6 +77,7 @@ if get_option('man-pages') and rst2man.found()
     [ 'gtk4-query-settings', '1', ],
     [ 'gtk4-rendernode-tool', '1' ],
     [ 'gtk4-update-icon-cache', '1', ],
+    [ 'gtk4-path-tool', '1', ],
   ]
 
   if get_option('demos')

docs/reference/gtk/section-accessibility.md

@@ -222,7 +222,7 @@ It is possible to set accessible attributes in UI files as well:
   <accessibility>
     <property name="label">Download</property>
     <relation name="labelled-by">label1</relation>
-  /accessibility>
+  </accessibility>
 </object>
 ```
 

gdk/gdkclipboard.c

@@ -297,7 +297,7 @@ gdk_clipboard_read_local_async (GdkClipboard        *clipboard,
     {
       GOutputStream *output_stream;
       GIOStream *stream;
-      
+
       stream = gdk_pipe_io_stream_new ();
       output_stream = g_io_stream_get_output_stream (stream);
       gdk_clipboard_write_async (clipboard,
@@ -767,7 +767,7 @@ gdk_clipboard_read_value_internal (GdkClipboard        *clipboard,
   GdkContentFormats *formats;
   GValue *value;
   GTask *task;
- 
+
   task = g_task_new (clipboard, cancellable, callback, user_data);
   g_task_set_priority (task, io_priority);
   g_task_set_source_tag (task, source_tag);
@@ -946,7 +946,7 @@ gdk_clipboard_read_texture_finish (GdkClipboard  *clipboard,
   value = g_task_propagate_pointer (G_TASK (result), error);
   if (!value)
     return NULL;
-  
+
   return g_value_dup_object (value);
 }
 
@@ -1011,7 +1011,7 @@ gdk_clipboard_read_text_finish (GdkClipboard  *clipboard,
   value = g_task_propagate_pointer (G_TASK (result), error);
   if (!value)
     return NULL;
-  
+
   return g_value_dup_string (value);
 }
 
@@ -1110,7 +1110,7 @@ gdk_clipboard_write_async (GdkClipboard        *clipboard,
       GError *error = NULL;
 
       g_assert (gtype != G_TYPE_INVALID);
-      
+
       g_value_init (&value, gtype);
       if (gdk_content_provider_get_value (priv->content, &value, &error))
         {
@@ -1126,7 +1126,7 @@ gdk_clipboard_write_async (GdkClipboard        *clipboard,
         {
           g_task_return_error (task, error);
         }
-      
+
       g_value_unset (&value);
     }
   else
@@ -1148,7 +1148,7 @@ gdk_clipboard_write_finish (GdkClipboard  *clipboard,
   g_return_val_if_fail (g_task_is_valid (result, clipboard), FALSE);
   g_return_val_if_fail (g_task_get_source_tag (G_TASK (result)) == gdk_clipboard_write_async, FALSE);
 
-  return g_task_propagate_boolean (G_TASK (result), error); 
+  return g_task_propagate_boolean (G_TASK (result), error);
 }
 
 static gboolean
@@ -1248,8 +1248,8 @@ gdk_clipboard_set_content (GdkClipboard       *clipboard,
  * Sets the clipboard to contain the value collected from the given varargs.
  *
  * Values should be passed the same way they are passed to other value
- * collecting APIs, such as [`method@GObject.Object.set`] or
- * [`func@GObject.signal_emit`].
+ * collecting APIs, such as [method@GObject.Object.set] or
+ * [func@GObject.signal_emit].
  *
  * ```c
  * gdk_clipboard_set (clipboard, GTK_TYPE_STRING, "Hello World");
@@ -1263,7 +1263,7 @@ gdk_clipboard_set (GdkClipboard *clipboard,
                    ...)
 {
   va_list args;
-                          
+
   g_return_if_fail (GDK_IS_CLIPBOARD (clipboard));
 
   va_start (args, type);

gdk/gdkglcontext.c

@@ -1528,7 +1528,8 @@ gdk_gl_context_check_extensions (GdkGLContext *context)
 
   if (gdk_gl_context_get_use_es (context))
     {
-      priv->has_unpack_subimage = epoxy_has_gl_extension ("GL_EXT_unpack_subimage");
+      priv->has_unpack_subimage = gdk_gl_version_greater_equal (&priv->gl_version, &GDK_GL_VERSION_INIT (3, 0)) ||
+                                  epoxy_has_gl_extension ("GL_EXT_unpack_subimage");
       priv->has_khr_debug = epoxy_has_gl_extension ("GL_KHR_debug");
     }
   else

gdk/gdkgltexture.c

@@ -95,10 +95,11 @@ static gboolean
 gdk_gl_texture_invoke_callback (gpointer data)
 {
   InvokeData *invoke = data;
-  GdkGLContext *context;
+  GdkGLContext *context, *previous;
 
   context = gdk_display_get_gl_context (gdk_gl_context_get_display (invoke->self->context));
 
+  previous = gdk_gl_context_get_current ();
   gdk_gl_context_make_current (context);
 
   if (invoke->self->sync && context != invoke->self->context)
@@ -110,6 +111,11 @@ gdk_gl_texture_invoke_callback (gpointer data)
 
   g_atomic_int_set (&invoke->spinlock, 1);
 
+  if (previous)
+    gdk_gl_context_make_current (previous);
+  else
+    gdk_gl_context_clear_current ();
+
   return FALSE;
 }
 
@@ -153,7 +159,7 @@ gdk_gl_texture_find_format (gboolean         use_es,
       if (gdk_memory_format_alpha (format) != alpha)
         continue;
 
-      if (!gdk_memory_format_gl_format (format, use_es, gl_major, gl_minor, &q_internal_format, &q_format, &q_type, &q_swizzle))
+      if (!gdk_memory_format_gl_format (format, use_es, gl_major, gl_minor, &q_internal_format, &q_format, &q_type, q_swizzle))
         continue;
 
       if (q_format != gl_format || q_type != gl_type)
@@ -188,7 +194,7 @@ gdk_gl_texture_do_download (GdkGLTexture *self,
                                    FALSE,
                                    major, minor,
                                    &gl_internal_format,
-                                   &gl_format, &gl_type, &gl_swizzle))
+                                   &gl_format, &gl_type, gl_swizzle))
     {
       if (download->stride == expected_stride &&
           download->format == format)

gdk/gdkmemoryformat.c

@@ -739,12 +739,12 @@ gdk_memory_format_gl_format (GdkMemoryFormat  format,
                              guint           *out_internal_format,
                              guint           *out_format,
                              guint           *out_type,
-                             GLint          (*out_swizzle)[4])
+                             GLint            out_swizzle[4])
 {
   *out_internal_format = memory_formats[format].gl.internal_format;
   *out_format = memory_formats[format].gl.format;
   *out_type = memory_formats[format].gl.type;
-  memcpy (out_swizzle, &memory_formats[format].gl.swizzle, sizeof(GLint) * 4);
+  memcpy (out_swizzle, memory_formats[format].gl.swizzle, sizeof(GLint) * 4);
 
   if (gles)
     {

gdk/gdkmemoryformatprivate.h

@@ -52,7 +52,7 @@ gboolean                gdk_memory_format_gl_format         (GdkMemoryFormat
                                                              guint                      *out_internal_format,
                                                              guint                      *out_format,
                                                              guint                      *out_type,
-                                                             GLint                     (*out_gizzle)[4]);
+                                                             GLint                       out_gizzle[4]);
 
 void                    gdk_memory_convert                  (guchar                     *dest_data,
                                                              gsize                       dest_stride,

gdk/gdkpaintable.c

@@ -25,10 +25,12 @@
 #include "gdkprivate.h"
 
 /* HACK: So we don't need to include any (not-yet-created) GSK or GTK headers */
+GdkSnapshot *   gtk_snapshot_new                        (void);
 void            gtk_snapshot_push_debug                 (GdkSnapshot            *snapshot,
                                                          const char             *message,
                                                          ...) G_GNUC_PRINTF (2, 3);
 void            gtk_snapshot_pop                        (GdkSnapshot            *snapshot);
+GdkPaintable *  gtk_snapshot_free_to_paintable          (GdkSnapshot            *snapshot);
 
 /**
  * GdkPaintable:
@@ -102,9 +104,21 @@ gdk_paintable_default_snapshot (GdkPaintable *paintable,
 static GdkPaintable *
 gdk_paintable_default_get_current_image (GdkPaintable *paintable)
 {
-  g_warning ("FIXME: implement by snapshotting at default size and returning a GskRendererNodePaintable");
+  int width, height;
+  GdkSnapshot *snapshot;
 
-  return paintable;
+  /* No need to check whether the paintable is static, as
+   * gdk_paintable_get_current_image () takes care of that already.  */
+
+  width = gdk_paintable_get_intrinsic_width (paintable);
+  height = gdk_paintable_get_intrinsic_height (paintable);
+
+  if (width <= 0 || height <= 0)
+    return gdk_paintable_new_empty (width, height);
+
+  snapshot = gtk_snapshot_new ();
+  gdk_paintable_snapshot (paintable, snapshot, width, height);
+  return gtk_snapshot_free_to_paintable (snapshot);
 }
 
 static GdkPaintableFlags

gdk/macos/gdkmacosglcontext-private.h

@@ -27,9 +27,7 @@
 #include "gdkmacosdisplay.h"
 #include "gdkmacossurface.h"
 
-#import <OpenGL/OpenGL.h>
-#import <OpenGL/gl3.h>
-#import <AppKit/AppKit.h>
+#import <epoxy/gl.h>
 
 G_BEGIN_DECLS
 

gdk/macos/gdkmacosglcontext.c

@@ -21,7 +21,6 @@
 
 #include "gdkconfig.h"
 
-#include <OpenGL/gl3.h>
 #include <OpenGL/CGLIOSurface.h>
 #include <QuartzCore/QuartzCore.h>
 
@@ -499,7 +498,7 @@ gdk_macos_gl_context_begin_frame (GdkDrawContext *context,
   gdk_gl_context_make_current (GDK_GL_CONTEXT (self));
   gdk_macos_gl_context_allocate (self);
 
-  GDK_DRAW_CONTEXT_CLASS (gdk_macos_gl_context_parent_class)->begin_frame (context, prefers_high_depth, region);
+  GDK_DRAW_CONTEXT_CLASS (gdk_macos_gl_context_parent_class)->begin_frame (context, depth, region);
 
   gdk_gl_context_make_current (GDK_GL_CONTEXT (self));
   CHECK_GL (NULL, glBindFramebuffer (GL_FRAMEBUFFER, self->fbo));

gdk/macos/gdkmacosmonitor.c

@@ -331,7 +331,7 @@ _gdk_macos_monitor_reconfigure (GdkMacosMonitor *self)
   gdk_monitor_set_physical_size (GDK_MONITOR (self), width_mm, height_mm);
   gdk_monitor_set_scale_factor (GDK_MONITOR (self), scale_factor);
   gdk_monitor_set_refresh_rate (GDK_MONITOR (self), refresh_rate);
-  gdk_monitor_set_subpixel_layout (GDK_MONITOR (self), GDK_SUBPIXEL_LAYOUT_UNKNOWN);
+  gdk_monitor_set_subpixel_layout (GDK_MONITOR (self), subpixel_layout);
 
   self->workarea = [screen visibleFrame];
 

gdk/wayland/gdkapplaunchcontext-wayland.c

@@ -93,7 +93,8 @@ gdk_wayland_app_launch_context_get_startup_notify_id (GAppLaunchContext *context
       id = app_launch_data.token;
       wl_event_queue_destroy (event_queue);
     }
-  else if (gtk_shell1_get_version (display->gtk_shell) >= GTK_SHELL1_NOTIFY_LAUNCH_SINCE_VERSION)
+  else if (display->gtk_shell &&
+           gtk_shell1_get_version (display->gtk_shell) >= GTK_SHELL1_NOTIFY_LAUNCH_SINCE_VERSION)
     {
       id = g_uuid_string_random ();
       gtk_shell1_notify_launch (display->gtk_shell, id);

gdk/wayland/meson.build

@@ -127,3 +127,6 @@ libgdk_wayland = static_library('gdk-wayland',
   link_with: [ libwayland_cursor, ],
   dependencies: [ gdk_deps, gdk_wayland_deps ],
 )
+
+# Used to generate pkg-config Requires
+wayland_public_deps = [wlclientdep]

gdk/win32/gdkevents-win32.c

@@ -2857,7 +2857,10 @@ gdk_event_translate (MSG *msg,
       break;
 
     case WM_SYSCOMMAND:
-      switch (msg->wParam)
+      /* From: https://learn.microsoft.com/en-us/windows/win32/menurc/wm-syscommand?redirectedfrom=MSDN
+       * To obtain the correct result when testing the value of wParam,
+       * an application must combine the value 0xFFF0 with the wParam value by using the bitwise AND operator. */
+      switch (msg->wParam & 0xFFF0)
 	{
 	case SC_MINIMIZE:
 	case SC_RESTORE:
@@ -2964,6 +2967,14 @@ gdk_event_translate (MSG *msg,
                   windowpos = (WINDOWPOS *) msg->lParam;
                   windowpos->cx = our_mmi.ptMaxSize.x;
                   windowpos->cy = our_mmi.ptMaxSize.y;
+
+                  if (!_gdk_win32_surface_lacks_wm_decorations (window) &&
+                      !(windowpos->flags & SWP_NOCLIENTSIZE) &&
+                      window->width == impl->next_layout.configured_width &&
+                      window->height == impl->next_layout.configured_height)
+                    {
+                      impl->inhibit_configure = TRUE;
+                    }
                 }
 
               impl->maximizing = FALSE;

gdk/win32/gdksurface-win32.c

@@ -1230,18 +1230,11 @@ get_effective_window_decorations (GdkSurface       *window,
 
       *decoration |= GDK_DECOR_MINIMIZE;
 
-      return TRUE;
-    }
-  else if (impl->hint_flags & GDK_HINT_MAX_SIZE)
-    {
-      *decoration = GDK_DECOR_ALL | GDK_DECOR_MAXIMIZE;
-      *decoration |= GDK_DECOR_MINIMIZE;
-
       return TRUE;
     }
   else
     {
-      *decoration = (GDK_DECOR_ALL | GDK_DECOR_MINIMIZE | GDK_DECOR_MAXIMIZE);
+      *decoration = GDK_DECOR_ALL;
       return TRUE;
     }
 

gdk/x11/gdkclipboard-x11.c

@@ -201,7 +201,7 @@ gdk_x11_clipboard_formats_to_targets (GdkContentFormats *formats)
             continue;
 
           if (g_str_equal (mime_types[i], special_targets[j].mime_type))
-            targets = g_slist_prepend (targets, (gpointer) g_intern_string (special_targets[j].x_target));
+            targets = g_slist_prepend (targets, (gpointer) g_intern_static_string (special_targets[j].x_target));
         }
       targets = g_slist_prepend (targets, (gpointer) mime_types[i]);
     }
@@ -238,6 +238,8 @@ gdk_x11_clipboard_formats_to_atoms (GdkDisplay        *display,
   for (l = targets; l; l = l->next)
     atoms[i++] = gdk_x11_get_xatom_by_name_for_display (display, l->data);
 
+  g_slist_free (targets);
+
   return atoms;
 }
 

gdk/x11/meson.build

@@ -86,3 +86,5 @@ libgdk_x11 = static_library('gdk-x11',
   ] + common_cflags,
   dependencies: [ gdk_deps, gdk_x11_deps, ],
 )
+
+x11_public_deps = [x11_dep]

gsk/broadway/gskbroadwayrenderer.c

@@ -271,6 +271,8 @@ collect_reused_child_nodes (GskRenderer *renderer,
     case GSK_CROSS_FADE_NODE:
     case GSK_BLUR_NODE:
     case GSK_MASK_NODE:
+    case GSK_FILL_NODE:
+    case GSK_STROKE_NODE:
 
     default:
 
@@ -859,6 +861,8 @@ gsk_broadway_renderer_add_node (GskRenderer *renderer,
     case GSK_CROSS_FADE_NODE:
     case GSK_BLUR_NODE:
     case GSK_GL_SHADER_NODE:
+    case GSK_FILL_NODE:
+    case GSK_STROKE_NODE:
     default:
       break; /* Fallback */
     }

gsk/gl/gskglcommandqueue.c

@@ -1456,7 +1456,7 @@ memory_format_gl_format (GdkMemoryFormat  data_format,
                          guint           *gl_internalformat,
                          guint           *gl_format,
                          guint           *gl_type,
-                         GLint          (*gl_swizzle)[4])
+                         GLint            gl_swizzle[4])
 {
   GdkMemoryDepth depth;
 
@@ -1577,7 +1577,7 @@ gsk_gl_command_queue_do_upload_texture_chunk (GskGLCommandQueue *self,
                                          &gl_internalformat,
                                          &gl_format,
                                          &gl_type,
-                                         &gl_swizzle);
+                                         gl_swizzle);
 
   gdk_texture_downloader_init (&downloader, texture);
   gdk_texture_downloader_set_format (&downloader, data_format);
@@ -1595,8 +1595,7 @@ gsk_gl_command_queue_do_upload_texture_chunk (GskGLCommandQueue *self,
     {
       glTexSubImage2D (GL_TEXTURE_2D, 0, x, y, width, height, gl_format, gl_type, data);
     }
-  else if (stride % bpp == 0 &&
-           (gdk_gl_context_check_version (self->context, NULL, "3.0") || gdk_gl_context_has_unpack_subimage (self->context)))
+  else if (stride % bpp == 0 && gdk_gl_context_has_unpack_subimage (self->context))
     {
       glPixelStorei (GL_UNPACK_ROW_LENGTH, stride / bpp);
 
@@ -1684,7 +1683,7 @@ gsk_gl_command_queue_upload_texture_chunks (GskGLCommandQueue    *self,
                                          &gl_internalformat,
                                          &gl_format,
                                          &gl_type,
-                                         &gl_swizzle);
+                                         gl_swizzle);
 
   glTexImage2D (GL_TEXTURE_2D, 0, gl_internalformat, width, height, 0, gl_format, gl_type, NULL);
 

gsk/gl/gskglrenderjob.c

@@ -255,6 +255,8 @@ node_supports_2d_transform (const GskRenderNode *node)
     case GSK_BLEND_NODE:
     case GSK_BLUR_NODE:
     case GSK_MASK_NODE:
+    case GSK_FILL_NODE:
+    case GSK_STROKE_NODE:
       return TRUE;
 
     case GSK_SHADOW_NODE:
@@ -309,6 +311,8 @@ node_supports_transform (const GskRenderNode *node)
     case GSK_BLEND_NODE:
     case GSK_BLUR_NODE:
     case GSK_MASK_NODE:
+    case GSK_FILL_NODE:
+    case GSK_STROKE_NODE:
       return TRUE;
 
     case GSK_SHADOW_NODE:
@@ -1241,9 +1245,9 @@ gsk_gl_render_job_visit_as_fallback (GskGLRenderJob      *job,
 done:
   if (scale_x < 0 || scale_y < 0)
     {
-      GskTransform *transform = gsk_transform_translate (NULL,
-                                                         &GRAPHENE_POINT_INIT (scale_x < 0 ? - surface_width : 0,
-                                                                               scale_y < 0 ? - surface_height : 0));
+      GskTransform *transform = gsk_transform_translate (gsk_transform_scale (NULL, scale_x < 0 ? -1 : 1, scale_y < 0 ? -1 : 1),
+                                                         &GRAPHENE_POINT_INIT (scale_x < 0 ? - (node->bounds.size.width + 2 * node->bounds.origin.x) : 0,
+                                                                               scale_y < 0 ? - (node->bounds.size.height + 2 * node->bounds.origin.y) : 0));
       gsk_gl_render_job_push_modelview (job, transform);
       gsk_transform_unref (transform);
     }
@@ -4089,6 +4093,14 @@ gsk_gl_render_job_visit_node (GskGLRenderJob      *job,
       gsk_gl_render_job_visit_as_fallback (job, node);
     break;
 
+    case GSK_FILL_NODE:
+      gsk_gl_render_job_visit_as_fallback (job, node);
+    break;
+
+    case GSK_STROKE_NODE:
+      gsk_gl_render_job_visit_as_fallback (job, node);
+    break;
+
     case GSK_NOT_A_RENDER_NODE:
     default:
       g_assert_not_reached ();

gsk/gsk.h

@@ -20,9 +20,14 @@
 #define __GSK_H_INSIDE__
 
 #include <gsk/gskenums.h>
+#include <gsk/gskpath.h>
+#include <gsk/gskpathbuilder.h>
+#include <gsk/gskpathmeasure.h>
+#include <gsk/gskpathpoint.h>
 #include <gsk/gskrenderer.h>
 #include <gsk/gskrendernode.h>
 #include <gsk/gskroundedrect.h>
+#include <gsk/gskstroke.h>
 #include <gsk/gsktransform.h>
 #include <gsk/gskglshader.h>
 

gsk/gskboundingboxprivate.h

@@ -0,0 +1,115 @@
+#pragma once
+
+#include <gsk/gsktypes.h>
+
+G_BEGIN_DECLS
+
+typedef struct _GskBoundingBox GskBoundingBox;
+
+struct _GskBoundingBox {
+  graphene_point_t min;
+  graphene_point_t max;
+};
+
+static inline GskBoundingBox *
+gsk_bounding_box_init (GskBoundingBox         *self,
+                       const graphene_point_t *a,
+                       const graphene_point_t *b)
+{
+  self->min.x = MIN (a->x, b->x);
+  self->min.y = MIN (a->y, b->y);
+  self->max.x = MAX (a->x, b->x);
+  self->max.y = MAX (a->y, b->y);
+  return self;
+}
+
+static inline GskBoundingBox *
+gsk_bounding_box_init_copy (GskBoundingBox       *self,
+                            const GskBoundingBox *src)
+{
+  self->min = src->min;
+  self->max = src->max;
+  return self;
+}
+
+static inline GskBoundingBox *
+gsk_bounding_box_init_from_rect (GskBoundingBox        *self,
+                                 const graphene_rect_t *bounds)
+{
+  self->min = bounds->origin;
+  self->max.x = bounds->origin.x + bounds->size.width;
+  self->max.y = bounds->origin.y + bounds->size.height;
+  return self;
+}
+
+static inline void
+gsk_bounding_box_expand (GskBoundingBox         *self,
+                         const graphene_point_t *p)
+{
+  self->min.x = MIN (self->min.x, p->x);
+  self->min.y = MIN (self->min.y, p->y);
+  self->max.x = MAX (self->max.x, p->x);
+  self->max.y = MAX (self->max.y, p->y);
+}
+
+static inline graphene_rect_t *
+gsk_bounding_box_to_rect (const GskBoundingBox  *self,
+                          graphene_rect_t       *rect)
+{
+  rect->origin = self->min;
+  rect->size.width = self->max.x - self->min.x;
+  rect->size.height = self->max.y - self->min.y;
+  return rect;
+}
+
+static inline gboolean
+gsk_bounding_box_contains_point (const GskBoundingBox   *self,
+                                 const graphene_point_t *p)
+{
+  return self->min.x <= p->x && p->x <= self->max.x &&
+         self->min.y <= p->y && p->y <= self->max.y;
+}
+
+static inline gboolean
+gsk_bounding_box_contains_point_with_epsilon (const GskBoundingBox   *self,
+                                              const graphene_point_t *p,
+                                              float                   epsilon)
+{
+  return self->min.x - epsilon <= p->x && p->x <= self->max.x + epsilon &&
+         self->min.y - epsilon <= p->y && p->y <= self->max.y + epsilon;
+}
+
+static inline gboolean
+gsk_bounding_box_intersection (const GskBoundingBox *a,
+                               const GskBoundingBox *b,
+                               GskBoundingBox       *res)
+{
+  graphene_point_t min, max;
+
+  min.x = MAX (a->min.x, b->min.x);
+  min.y = MAX (a->min.y, b->min.y);
+  max.x = MIN (a->max.x, b->max.x);
+  max.y = MIN (a->max.y, b->max.y);
+
+  if (res)
+    gsk_bounding_box_init (res, &min, &max);
+
+  return min.x <= max.x && min.y <= max.y;
+}
+
+static inline void
+gsk_bounding_box_union (const GskBoundingBox *a,
+                        const GskBoundingBox *b,
+                        GskBoundingBox       *res)
+{
+  graphene_point_t min, max;
+
+  min.x = MIN (a->min.x, b->min.x);
+  min.y = MIN (a->min.y, b->min.y);
+  max.x = MAX (a->max.x, b->max.x);
+  max.y = MAX (a->max.y, b->max.y);
+
+  gsk_bounding_box_init (res, &min, &max);
+}
+
+G_END_DECLS

gsk/gskcontourprivate.h

@@ -0,0 +1,102 @@
+/*
+ * Copyright © 2020 Benjamin Otte
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+
+#pragma once
+
+#include "gskpathprivate.h"
+#include "gskpathpoint.h"
+#include "gskpathopprivate.h"
+#include "gskboundingboxprivate.h"
+
+G_BEGIN_DECLS
+
+GskContour *            gsk_standard_contour_new                (GskPathFlags            flags,
+                                                                 const graphene_point_t *points,
+                                                                 gsize                   n_points,
+                                                                 const gskpathop        *ops,
+                                                                 gsize                   n_ops,
+                                                                 gssize                  offset);
+
+GskContour *            gsk_circle_contour_new                  (const graphene_point_t *center,
+                                                                 float                   radius);
+GskContour *            gsk_rect_contour_new                    (const graphene_rect_t  *rect);
+GskContour *            gsk_rounded_rect_contour_new            (const GskRoundedRect   *rounded_rect);
+
+const char *            gsk_contour_get_type_name               (const GskContour       *self);
+void                    gsk_contour_copy                        (GskContour *            dest,
+                                                                 const GskContour       *src);
+GskContour *            gsk_contour_dup                         (const GskContour       *src);
+GskContour *            gsk_contour_reverse                     (const GskContour       *src);
+
+gsize                   gsk_contour_get_size                    (const GskContour       *self);
+GskPathFlags            gsk_contour_get_flags                   (const GskContour       *self);
+void                    gsk_contour_print                       (const GskContour       *self,
+                                                                 GString                *string);
+gboolean                gsk_contour_get_bounds                  (const GskContour       *self,
+                                                                 GskBoundingBox         *bounds);
+gboolean                gsk_contour_get_stroke_bounds           (const GskContour       *self,
+                                                                 const GskStroke        *stroke,
+                                                                 GskBoundingBox         *bounds);
+gboolean                gsk_contour_foreach                     (const GskContour       *self,
+                                                                 GskPathForeachFunc      func,
+                                                                 gpointer                user_data);
+int                     gsk_contour_get_winding                 (const GskContour       *self,
+                                                                 const graphene_point_t *point);
+gsize                   gsk_contour_get_n_ops                   (const GskContour       *self);
+gboolean                gsk_contour_get_closest_point           (const GskContour       *self,
+                                                                 const graphene_point_t *point,
+                                                                 float                   threshold,
+                                                                 GskPathPoint           *result,
+                                                                 float                  *out_dist);
+void                    gsk_contour_get_position                (const GskContour       *self,
+                                                                 const GskPathPoint     *point,
+                                                                 graphene_point_t       *pos);
+void                    gsk_contour_get_tangent                 (const GskContour       *self,
+                                                                 const GskPathPoint     *point,
+                                                                 GskPathDirection        direction,
+                                                                 graphene_vec2_t        *tangent);
+float                   gsk_contour_get_curvature               (const GskContour       *self,
+                                                                 const GskPathPoint     *point,
+                                                                 GskPathDirection        direction,
+                                                                 graphene_point_t       *center);
+void                    gsk_contour_add_segment                 (const GskContour       *self,
+                                                                 GskPathBuilder         *builder,
+                                                                 gboolean                emit_move_to,
+                                                                 const GskPathPoint     *start,
+                                                                 const GskPathPoint     *end);
+
+gpointer                gsk_contour_init_measure                (const GskContour       *self,
+                                                                 float                   tolerance,
+                                                                 float                  *out_length);
+void                    gsk_contour_free_measure                (const GskContour       *self,
+                                                                 gpointer                data);
+void                    gsk_contour_get_point                   (const GskContour       *self,
+                                                                 gpointer                measure_data,
+                                                                 float                   distance,
+                                                                 GskPathPoint           *result);
+float                   gsk_contour_get_distance                (const GskContour       *self,
+                                                                 const GskPathPoint     *point,
+                                                                 gpointer                measure_data);
+gboolean                gsk_contour_dash                        (const GskContour       *contour,
+                                                                 GskStroke              *stroke,
+                                                                 GskPathForeachFunc      func,
+                                                                 gpointer                user_data);
+
+G_END_DECLS

gsk/gskcurve-ct-values.c

@@ -0,0 +1,272 @@
+/* Legendre-Gauss values,
+ * see https://pomax.github.io/bezierinfo/legendre-gauss.html
+ */
+
+#if defined(USE_64_SAMPLES)
+/* n = 64 */
+static const double T[] = {
+	-0.0243502926634244325089558428537156614268871093149758091634531663960566965166295288529853061657116894882370493013671717560479926679408068852617342586968190919443025679363843727751902756254975073084367002129407854253246662805532069172532219089321005870178809284335033318073251039701073379759,
+	0.0243502926634244325089558428537156614268871093149758091634531663960566965166295288529853061657116894882370493013671717560479926679408068852617342586968190919443025679363843727751902756254975073084367002129407854253246662805532069172532219089321005870178809284335033318073251039701073379759,
+	-0.0729931217877990394495429419403374932441261816687788533563163323377395217254429050181833064967505478802134768007678458612956459126148837496307967995621683597067400860540057918571357609346700883624064782909888895547912499697295335516804810990011835717296819569741981551097569810739977931249,
+	0.0729931217877990394495429419403374932441261816687788533563163323377395217254429050181833064967505478802134768007678458612956459126148837496307967995621683597067400860540057918571357609346700883624064782909888895547912499697295335516804810990011835717296819569741981551097569810739977931249,
+	-0.1214628192961205544703764634922478782186836383371912940423495826006931832245070944213952236889690237679661122848626352437115925113582515415979746598665681268376919737373113667247142315234607397986222184384307059013512155412722263090766858403726100735651684437098923088469949297570988091677,
+	0.1214628192961205544703764634922478782186836383371912940423495826006931832245070944213952236889690237679661122848626352437115925113582515415979746598665681268376919737373113667247142315234607397986222184384307059013512155412722263090766858403726100735651684437098923088469949297570988091677,
+	-0.1696444204239928180373136297482698441999902667343778505894178746884342357796505591325925801106834127602396624627746208498838190598644711533868179088757129652678801285453336384132061358206434768209251779433993367981112053126660575920785488821886662635718276505127786854167528795165050389903,
+	0.1696444204239928180373136297482698441999902667343778505894178746884342357796505591325925801106834127602396624627746208498838190598644711533868179088757129652678801285453336384132061358206434768209251779433993367981112053126660575920785488821886662635718276505127786854167528795165050389903,
+	-0.217423643740007084149648748988822617578485831141222348630380401885689634737659235537163737740243604800759921292790013642836998201691226098978544332296437547642195961469059807833597096166848933098833151166287901339013986496737408125314858259377210847115061960167857239951500335854820530586,
+	0.217423643740007084149648748988822617578485831141222348630380401885689634737659235537163737740243604800759921292790013642836998201691226098978544332296437547642195961469059807833597096166848933098833151166287901339013986496737408125314858259377210847115061960167857239951500335854820530586,
+	-0.2646871622087674163739641725100201179804131362950932439559895448126206429452852982016450901649805445999078728714943692622330016257776575354105370883948495294882935681426154386660616476411740312465060150591301869544672050088454083442813632094277160007745547301572849406353682760306061929911,
+	0.2646871622087674163739641725100201179804131362950932439559895448126206429452852982016450901649805445999078728714943692622330016257776575354105370883948495294882935681426154386660616476411740312465060150591301869544672050088454083442813632094277160007745547301572849406353682760306061929911,
+	-0.3113228719902109561575126985601568835577153578680501269954571709858169098868398268719654999460149709757804582988077747605532896065842023340674450299515989484487746153929299031759475919924980452933324186984188982046762542556035347023744560814177013801414889023264804693830155588690576492164,
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+	-0.9963401167719552793469245006763991232098575063402266121352522199507030568202208530946066801021703916301511794658310735397567341036554686814952726523955953805437164277655915410358813984246580862850974195805395101678543649116458555272523253307828290553873260588621490898443701779725568118502,
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+	-0.9993050417357721394569056243456363119697121916756087760628072954617646543505331997843242376462639434945376776512170265314011232493020401570891594274831367800115383317335285468800574240152992751785027563437707875403545865305271045717258142571193695943317890367167086616955235477529427992282,
+	0.9993050417357721394569056243456363119697121916756087760628072954617646543505331997843242376462639434945376776512170265314011232493020401570891594274831367800115383317335285468800574240152992751785027563437707875403545865305271045717258142571193695943317890367167086616955235477529427992282
+};
+
+static const double C[] = {
+	0.0486909570091397203833653907347499124426286922838743305086688042456914190998246107310291565645676057401607079939845156005172257043376703767287395573765236401039685866479381075274920900511719320271157129622463682509122641788910270632229694394595885032921037399187298767076084601033342936131,
+	0.0486909570091397203833653907347499124426286922838743305086688042456914190998246107310291565645676057401607079939845156005172257043376703767287395573765236401039685866479381075274920900511719320271157129622463682509122641788910270632229694394595885032921037399187298767076084601033342936131,
+	0.0485754674415034269347990667839781136875565447049294857111516761025158193093697039229163427633930410186232149083923688162761488505704450697417589593116703853157329164894580165517236877241308351214870169600093357854651930986960906313726182992933363325614247750209880050786299287510692780499,
+	0.0485754674415034269347990667839781136875565447049294857111516761025158193093697039229163427633930410186232149083923688162761488505704450697417589593116703853157329164894580165517236877241308351214870169600093357854651930986960906313726182992933363325614247750209880050786299287510692780499,
+	0.048344762234802957169769527158017809703692550609501080629442201445249828946429202156764153264348308119169811534137999799779908820312744765416129733427088646813066886130539178187597540312913636916139844188190193872629488730769015964208394624398401975043997268903006190530430762197842013971,
+	0.048344762234802957169769527158017809703692550609501080629442201445249828946429202156764153264348308119169811534137999799779908820312744765416129733427088646813066886130539178187597540312913636916139844188190193872629488730769015964208394624398401975043997268903006190530430762197842013971,
+	0.0479993885964583077281261798713460699543167134714936209446323930933335214619650277588138568504103427609283146728470455041360837549685364869161566863222680599110109210456299588352028330169041000166382937545505655464884266691630625402297821494221827392164049587946530563778771030124675514431,
+	0.0479993885964583077281261798713460699543167134714936209446323930933335214619650277588138568504103427609283146728470455041360837549685364869161566863222680599110109210456299588352028330169041000166382937545505655464884266691630625402297821494221827392164049587946530563778771030124675514431,
+	0.0475401657148303086622822069442231716408252512625387521584740318784735191312349586041971325618543660076682369564304738487584849740943805934034367382833518752314207901993991333786062812015195073547884746598535775062676699885664167707011249029305697669004958515813436770491520105115843742005,
+	0.0475401657148303086622822069442231716408252512625387521584740318784735191312349586041971325618543660076682369564304738487584849740943805934034367382833518752314207901993991333786062812015195073547884746598535775062676699885664167707011249029305697669004958515813436770491520105115843742005,
+	0.0469681828162100173253262857545810751998975284738125649829240886861900500181800807437012381630302198876925642461830694029139318555787845567143614289552410495903601238284556145544858090965965782916339169651505119399637862876053945518410353459767034026687936026945199383607112976484520939933,
+	0.0469681828162100173253262857545810751998975284738125649829240886861900500181800807437012381630302198876925642461830694029139318555787845567143614289552410495903601238284556145544858090965965782916339169651505119399637862876053945518410353459767034026687936026945199383607112976484520939933,
+	0.0462847965813144172959532492322611849696503075324468007778340818364698861774606986244241539105685321088517142947579291476238551538798963436740600968513359005801910700069462154098456091711311098901749803777735222026075473081311483686560830539773763176758567914860207820170792365910140063798,
+	0.0462847965813144172959532492322611849696503075324468007778340818364698861774606986244241539105685321088517142947579291476238551538798963436740600968513359005801910700069462154098456091711311098901749803777735222026075473081311483686560830539773763176758567914860207820170792365910140063798,
+	0.0454916279274181444797709969712690588873234618023998968168834081606504637618082102750954507142497706775055424364453740562113890878382679420378787427100982909191308430750899201141096789461078632697297091763378573830284133736378128577579722120264252594541491899441765769262904055702701625378,
+	0.0454916279274181444797709969712690588873234618023998968168834081606504637618082102750954507142497706775055424364453740562113890878382679420378787427100982909191308430750899201141096789461078632697297091763378573830284133736378128577579722120264252594541491899441765769262904055702701625378,
+	0.0445905581637565630601347100309448432940237999912217256432193286861948363377761089569585678875932857237669096941854082976565514031401996407675401022860761183118504326746863327792604337217763335682212515058414863183914930810334329596384915832703655935958010948424747251920190851700662833367,
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+	0.0435837245293234533768278609737374809227888974971180150532193925502569499020021803936448815937567079991401855477391110804568848623412043870399620479222000249538880795788245633051476595555730388360811011823841525667998427392843673284072004068821750061964976796287623004834501604656318714989,
+	0.0424735151236535890073397679088173661655466481806496697314607722055245433487169327182398988553670128358787507582463602377168227019625334754497484024668087975720049504975593281010888062806587161032924284354938115463233015024659299046001504100674918329532481611571863222497170398830691222425,
+	0.0424735151236535890073397679088173661655466481806496697314607722055245433487169327182398988553670128358787507582463602377168227019625334754497484024668087975720049504975593281010888062806587161032924284354938115463233015024659299046001504100674918329532481611571863222497170398830691222425,
+	0.0412625632426235286101562974736380477399306355305474105429034779122704951178045914463267035032832336161816547420067160277921114474557623647771372636679857599931025531633255548770293397336318597716427093310378312957479805159734598610664983115148350548735211568465338522875618805992499897174,
+	0.0412625632426235286101562974736380477399306355305474105429034779122704951178045914463267035032832336161816547420067160277921114474557623647771372636679857599931025531633255548770293397336318597716427093310378312957479805159734598610664983115148350548735211568465338522875618805992499897174,
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+	0.0201348231535302093723403167285438970895266801007919519220072343276769828211923597982299498416998597995443052252531684909219367615574440281549241161294448697202959593344989612626641188010558013085389491205901106884167596038790695150496733123662891637942237462337673353651179115491957031948,
+	0.0201348231535302093723403167285438970895266801007919519220072343276769828211923597982299498416998597995443052252531684909219367615574440281549241161294448697202959593344989612626641188010558013085389491205901106884167596038790695150496733123662891637942237462337673353651179115491957031948,
+	0.0179517157756973430850453020011193688971673570364158572977184273569247295870620984743089140579199272107974903016785911970727080884655646148340637373001805876560334052431930062983734905886704331100259778249929425439377011315288821865303197904492848823994202996722656114004109123107733596987,
+	0.0179517157756973430850453020011193688971673570364158572977184273569247295870620984743089140579199272107974903016785911970727080884655646148340637373001805876560334052431930062983734905886704331100259778249929425439377011315288821865303197904492848823994202996722656114004109123107733596987,
+	0.0157260304760247193219659952975397944260290098431565121528943932284210502164124556525745628476326997189475680077625258949765335021586482683126547283634704087193102431454662772463321304938516661086261262080252305539171654570677889578063634007609097342035360186636479612243231917699790225637,
+	0.0157260304760247193219659952975397944260290098431565121528943932284210502164124556525745628476326997189475680077625258949765335021586482683126547283634704087193102431454662772463321304938516661086261262080252305539171654570677889578063634007609097342035360186636479612243231917699790225637,
+	0.0134630478967186425980607666859556841084257719773496708184682785221983598894666268489697837056105038485845901773961664652581563686185523959473293683490869846700009741156668864960127745507806046701586435579547632680339906665338521813319281296935586498194608460412423723103161161922347608637,
+	0.0134630478967186425980607666859556841084257719773496708184682785221983598894666268489697837056105038485845901773961664652581563686185523959473293683490869846700009741156668864960127745507806046701586435579547632680339906665338521813319281296935586498194608460412423723103161161922347608637,
+	0.011168139460131128818590493019208135072778797816827287215251362273969701224836131369547661822970774719521543690039908073147476182135228738610704246958518755712518444434075738269866120460156365855324768445411463643114925829148750923090201475035559533993035986264487097245733097728698218563,
+	0.011168139460131128818590493019208135072778797816827287215251362273969701224836131369547661822970774719521543690039908073147476182135228738610704246958518755712518444434075738269866120460156365855324768445411463643114925829148750923090201475035559533993035986264487097245733097728698218563,
+	0.0088467598263639477230309146597306476951762660792204997984715769296110380005985367341694286322550520156167431790573509593010611842062630262878798782558974712042810219159674181580449655112696028911646066461502678711637780164986283350190669684468398617127841853445303466680698660632269500149,
+	0.0088467598263639477230309146597306476951762660792204997984715769296110380005985367341694286322550520156167431790573509593010611842062630262878798782558974712042810219159674181580449655112696028911646066461502678711637780164986283350190669684468398617127841853445303466680698660632269500149,
+	0.0065044579689783628561173603999812667711317610549523400952448792575685125717613068203530526491113296049409911387320826711045787146267036866881961532403342811327869183281273743976710008917886491097375367147212074243884772614562628844975421736416404173672075979097191581386023407454532945934,
+	0.0065044579689783628561173603999812667711317610549523400952448792575685125717613068203530526491113296049409911387320826711045787146267036866881961532403342811327869183281273743976710008917886491097375367147212074243884772614562628844975421736416404173672075979097191581386023407454532945934,
+	0.0041470332605624676352875357285514153133028192536848024628763661431834776690157393776820933106187137592011723199002845429836606307797425496666456172753165824787973801175029578301513761259541022471768825518482406145696380621686627285992715643614469568410535180218496973657001203470470418364,
+	0.0041470332605624676352875357285514153133028192536848024628763661431834776690157393776820933106187137592011723199002845429836606307797425496666456172753165824787973801175029578301513761259541022471768825518482406145696380621686627285992715643614469568410535180218496973657001203470470418364,
+	0.0017832807216964329472960791449719331799593472719279556695308063655858546954239803486698215802150348282744786016134857283616955449868451969230490863774274598030023211055562492709717566919237924255297982774711177411074145151155610163293142044147991553384925940046957893721166251082473659733,
+	0.0017832807216964329472960791449719331799593472719279556695308063655858546954239803486698215802150348282744786016134857283616955449868451969230490863774274598030023211055562492709717566919237924255297982774711177411074145151155610163293142044147991553384925940046957893721166251082473659733
+};
+
+#elif defined(USE_32_SAMPLES)
+/* n = 32 */
+
+static double T[] = {
+	-0.0483076656877383162348125704405021636908472517308488971677937345463685926042778777794060365911173780988289503411375793689757446357461295741679964108035347980667582792392651327368009453047606446744575790523465655622949909588624860214137051585425884056992683442137333250625173849291299678673,
+	0.0483076656877383162348125704405021636908472517308488971677937345463685926042778777794060365911173780988289503411375793689757446357461295741679964108035347980667582792392651327368009453047606446744575790523465655622949909588624860214137051585425884056992683442137333250625173849291299678673,
+	-0.1444719615827964934851863735988106522038459913156355521379528938242184438164519731102406769974924713989580220758441301598578946580142268413547299935841673092513202403499286272686350814272974392746706128556678811982653393383080797337231702069432462445053984587997153683967433095128570624414,
+	0.1444719615827964934851863735988106522038459913156355521379528938242184438164519731102406769974924713989580220758441301598578946580142268413547299935841673092513202403499286272686350814272974392746706128556678811982653393383080797337231702069432462445053984587997153683967433095128570624414,
+	-0.2392873622521370745446032091655015206088554219602530155470960995597029133039943915553593695844147813728958071901224632260145752503694970545640339873418480550362677768010887468668377893757173424222709744116861683634989914911762187599464033126988486345234374380695224452457957624756811128321,
+	0.2392873622521370745446032091655015206088554219602530155470960995597029133039943915553593695844147813728958071901224632260145752503694970545640339873418480550362677768010887468668377893757173424222709744116861683634989914911762187599464033126988486345234374380695224452457957624756811128321,
+	-0.3318686022821276497799168057301879961957751368050598360182296306285376829657438169809731852312743263005943551508559377834274303920771100489026913715847854727626540340157368609696698131829681988642689780208633461925468064919389286805624602715005948661328152252049795463242055567997437182143,
+	0.3318686022821276497799168057301879961957751368050598360182296306285376829657438169809731852312743263005943551508559377834274303920771100489026913715847854727626540340157368609696698131829681988642689780208633461925468064919389286805624602715005948661328152252049795463242055567997437182143,
+	-0.4213512761306353453641194361724264783358772886324433305416613404557190462549837315607633055675740638739884093394574651160978879545562247406839036854173715776910866941643197988581928900702286425821151586000969947406313405310082646561917980302543820974679501841964453794193724645925031841919,
+	0.4213512761306353453641194361724264783358772886324433305416613404557190462549837315607633055675740638739884093394574651160978879545562247406839036854173715776910866941643197988581928900702286425821151586000969947406313405310082646561917980302543820974679501841964453794193724645925031841919,
+	-0.5068999089322293900237474743778212301802836995994354639743662809707712640478764442266190213124522047999876916596854537447047905434649918210338296049592120273725464263651562560829050004258268002241145951271730860506703690843719936432852920782304931272053564539127514959875734718036950073563,
+	0.5068999089322293900237474743778212301802836995994354639743662809707712640478764442266190213124522047999876916596854537447047905434649918210338296049592120273725464263651562560829050004258268002241145951271730860506703690843719936432852920782304931272053564539127514959875734718036950073563,
+	-0.5877157572407623290407454764018268584509401154544205727031788473129228586684474311408145102018661764979429510790747919023774933113319119601088669936958908618326367715806216053155906936017362413244183150445492317940727345571648726363597097311647731726438279098059670236086983675374932643925,
+	0.5877157572407623290407454764018268584509401154544205727031788473129228586684474311408145102018661764979429510790747919023774933113319119601088669936958908618326367715806216053155906936017362413244183150445492317940727345571648726363597097311647731726438279098059670236086983675374932643925,
+	-0.6630442669302152009751151686632383689770222859605053010170834964924461749232229404368981536611965356686820332804126742949900731319113817214392193185613161549689934301410316417342588149871686184296988807305719690974644891055567340650986465615021143958920599684258616066247948224049997371166,
+	0.6630442669302152009751151686632383689770222859605053010170834964924461749232229404368981536611965356686820332804126742949900731319113817214392193185613161549689934301410316417342588149871686184296988807305719690974644891055567340650986465615021143958920599684258616066247948224049997371166,
+	-0.732182118740289680387426665091267146630270483506629100821139573270385253587797727611292298988652560055905228466313310601075333829094630570926240639601009902567982815376254840388565733846030450161774620971196087756484387383432502715118096615117242484073636640563609696801484680439912327302,
+	0.732182118740289680387426665091267146630270483506629100821139573270385253587797727611292298988652560055905228466313310601075333829094630570926240639601009902567982815376254840388565733846030450161774620971196087756484387383432502715118096615117242484073636640563609696801484680439912327302,
+	-0.7944837959679424069630972989704289020954794016388354532507582449720593922816426654241878967890821228397041480126630294067578180914548706957761322921470535094589673860419616615738928385807346185892317514562489971543238450942224396667500582904031225063621511429185567036727089257387570529468,
+	0.7944837959679424069630972989704289020954794016388354532507582449720593922816426654241878967890821228397041480126630294067578180914548706957761322921470535094589673860419616615738928385807346185892317514562489971543238450942224396667500582904031225063621511429185567036727089257387570529468,
+	-0.849367613732569970133693004967742538954886793049759233100219598613724656141562558741881463752754991143937635778596582088915769685796612254240615386941355933272723068952531445772190363422003834495043219316062885999846179078139659341918527603834809670576387535564876596379488780285979062125,
+	0.849367613732569970133693004967742538954886793049759233100219598613724656141562558741881463752754991143937635778596582088915769685796612254240615386941355933272723068952531445772190363422003834495043219316062885999846179078139659341918527603834809670576387535564876596379488780285979062125,
+	-0.8963211557660521239653072437192122684789964967957595765636154129650249794910409173494503783167666654202705333374285522819507600044591355080910768854012859468015827508424619812224062460791781333400979810176198916239783226706506012473250929962326307746466256167673927887144428859779028909399,
+	0.8963211557660521239653072437192122684789964967957595765636154129650249794910409173494503783167666654202705333374285522819507600044591355080910768854012859468015827508424619812224062460791781333400979810176198916239783226706506012473250929962326307746466256167673927887144428859779028909399,
+	-0.9349060759377396891709191348354093255286714322828372184584037398118161947182932855418880831417927728359606280450921427988850058691931014887248988124656348299653052688344696135840215712191162135178273756415771123010111796122671724143565383396162107206772781551029308751511942924942333859805,
+	0.9349060759377396891709191348354093255286714322828372184584037398118161947182932855418880831417927728359606280450921427988850058691931014887248988124656348299653052688344696135840215712191162135178273756415771123010111796122671724143565383396162107206772781551029308751511942924942333859805,
+	-0.9647622555875064307738119281182749603888952204430187193220113218370995254867038008243801877562227002840740910741483519987441236283464394249183812395373150090695515823078220949436846111682404866338388944248976976566275875721000356873959697266702651250019105084704924793016185368873243713355,
+	0.9647622555875064307738119281182749603888952204430187193220113218370995254867038008243801877562227002840740910741483519987441236283464394249183812395373150090695515823078220949436846111682404866338388944248976976566275875721000356873959697266702651250019105084704924793016185368873243713355,
+	-0.9856115115452683354001750446309019786323957143358063182107821705820305847193755946663846485510970266115353839862364606643634021712823093784875255943834038377710426488328772047833289470320023596895438028281274741367781028592272459887917924171204666683239464005128153533797603112851826904814,
+	0.9856115115452683354001750446309019786323957143358063182107821705820305847193755946663846485510970266115353839862364606643634021712823093784875255943834038377710426488328772047833289470320023596895438028281274741367781028592272459887917924171204666683239464005128153533797603112851826904814,
+	-0.9972638618494815635449811286650407271385376637294611593011185457862359083917418520130456693085426416474280482200936551645510686196373231416035137741332968299789863385253514914078766236061488136738023162574655835389902337937054326098485227311719825229066712510246574949376367552421728646398,
+	0.9972638618494815635449811286650407271385376637294611593011185457862359083917418520130456693085426416474280482200936551645510686196373231416035137741332968299789863385253514914078766236061488136738023162574655835389902337937054326098485227311719825229066712510246574949376367552421728646398
+};
+
+static double C[] = {
+	0.0965400885147278005667648300635757947368606312355700687323182099577497758679466512968173871061464644599963197828969869820251559172455698832434930732077927850876632725829187045819145660710266452161095406358159608874152584850413283587913891015545638518881205600825069096855488296437485836866,
+	0.0965400885147278005667648300635757947368606312355700687323182099577497758679466512968173871061464644599963197828969869820251559172455698832434930732077927850876632725829187045819145660710266452161095406358159608874152584850413283587913891015545638518881205600825069096855488296437485836866,
+	0.0956387200792748594190820022041311005948905081620055509529898509437067444366006256133614167190847508238474888230077112990752876436158047205555474265705582078453283640212465537132165041268773645168746774530146140911679782502276289938840330631903789120176765314495900053061764438990021439069,
+	0.0956387200792748594190820022041311005948905081620055509529898509437067444366006256133614167190847508238474888230077112990752876436158047205555474265705582078453283640212465537132165041268773645168746774530146140911679782502276289938840330631903789120176765314495900053061764438990021439069,
+	0.0938443990808045656391802376681172600361000757462364500506275696355695118623098075097804207682530277555307864917078828352419853248607668520631751470962234105835015158485760721979732297206950719908744248285672032436598213262204039212897239890934116841559005147755270269705682414708355646603,
+	0.0938443990808045656391802376681172600361000757462364500506275696355695118623098075097804207682530277555307864917078828352419853248607668520631751470962234105835015158485760721979732297206950719908744248285672032436598213262204039212897239890934116841559005147755270269705682414708355646603,
+	0.0911738786957638847128685771116370625448614132753900053231278739777031520613017513597426417145878622654027367650308019870251963114683369110451524174258161390823876554910693202594383388549640738095422966058367070348943662290656339592299608558384147559830707904449930677260444604329157917977,
+	0.0911738786957638847128685771116370625448614132753900053231278739777031520613017513597426417145878622654027367650308019870251963114683369110451524174258161390823876554910693202594383388549640738095422966058367070348943662290656339592299608558384147559830707904449930677260444604329157917977,
+	0.0876520930044038111427714627518022875484497217017572223192228034747061150211380239263021665771581379364685191248848158059408000065275041643745927401342920150588893827207354226012701872322225514682178439577327346929209121046816487338309068375228210705166692551938339727096609740531893725675,
+	0.0876520930044038111427714627518022875484497217017572223192228034747061150211380239263021665771581379364685191248848158059408000065275041643745927401342920150588893827207354226012701872322225514682178439577327346929209121046816487338309068375228210705166692551938339727096609740531893725675,
+	0.0833119242269467552221990746043486115387468839428344598401864047287594069244380966536255650452315042012372905572506028852130723585016898197140339352228963465326746426938359210160503509807644396182380868089959855742801355208471205261406307895519604387550841954817025499019984032594036141439,
+	0.0833119242269467552221990746043486115387468839428344598401864047287594069244380966536255650452315042012372905572506028852130723585016898197140339352228963465326746426938359210160503509807644396182380868089959855742801355208471205261406307895519604387550841954817025499019984032594036141439,
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+	0.0658222227763618468376500637069387728775364473732465153710916696852412442018627316280044447764609054151761388378861151807154113495715653711918644796313239555117970398473141615070299152284100887258072240524028885129828725430021172354299810423059697133688823072212214503334259555369485963074,
+	0.0658222227763618468376500637069387728775364473732465153710916696852412442018627316280044447764609054151761388378861151807154113495715653711918644796313239555117970398473141615070299152284100887258072240524028885129828725430021172354299810423059697133688823072212214503334259555369485963074,
+	0.0586840934785355471452836373001708867501204674575467587150032786132877518019090643743123653437052116901895704813134467814193905269714480573030647540887991405215103758723074481312705449946311993670933802369300463315125015975216910705047901943865293781921122370996257470349807212516159332678,
+	0.0586840934785355471452836373001708867501204674575467587150032786132877518019090643743123653437052116901895704813134467814193905269714480573030647540887991405215103758723074481312705449946311993670933802369300463315125015975216910705047901943865293781921122370996257470349807212516159332678,
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+	0.0509980592623761761961632446895216952601847767397628437069071236525030510385137821267442193868358292147899714519363571211100873456269865150186456681043804358654826791768545393024953758025593924464295555854744882720755747096079325496814455853004350452095212995888025282619932613606999567133,
+	0.0428358980222266806568786466061255284928108575989407395620219408911043916962572261359138025961596979511472539467367407419206021900868371610612953162236233351132214438513203223655531564777278515080476421262443325932320214191168239648611793958596884827086182431203349730049744697408543115307,
+	0.0428358980222266806568786466061255284928108575989407395620219408911043916962572261359138025961596979511472539467367407419206021900868371610612953162236233351132214438513203223655531564777278515080476421262443325932320214191168239648611793958596884827086182431203349730049744697408543115307,
+	0.0342738629130214331026877322523727069948402029116274337814057454192310522168984446294442724624445760666244242305266023810860790282088335398182296698622433517061843276344829146573593201201081743714879684153735672789104567624853712011151505225193933019375481618760594889854480408562043658635,
+	0.0342738629130214331026877322523727069948402029116274337814057454192310522168984446294442724624445760666244242305266023810860790282088335398182296698622433517061843276344829146573593201201081743714879684153735672789104567624853712011151505225193933019375481618760594889854480408562043658635,
+	0.0253920653092620594557525897892240292875540475469487209362512822192154788532376645960457016338988332029324531233401833547954942765653767672102838323550828207273795044402516181251040411735351747299230615776597356956641506445501689924551185923348003766988424170511157069264716719906995309826,
+	0.0253920653092620594557525897892240292875540475469487209362512822192154788532376645960457016338988332029324531233401833547954942765653767672102838323550828207273795044402516181251040411735351747299230615776597356956641506445501689924551185923348003766988424170511157069264716719906995309826,
+	0.0162743947309056706051705622063866181795429637952095664295931749613369651752917857651844425586692833071042366002861684552859449530958901379260437604156888337987656773068694383447504913457771896770689760342192010638946676879735404121702279005140285599424477022083127753774756520463311689155,
+	0.0162743947309056706051705622063866181795429637952095664295931749613369651752917857651844425586692833071042366002861684552859449530958901379260437604156888337987656773068694383447504913457771896770689760342192010638946676879735404121702279005140285599424477022083127753774756520463311689155,
+	0.0070186100094700966004070637388531825133772207289396032320082356192151241454178686953297376907573215077936155545790593837513204206518026084505878987243348925784479817181234617862457418214505322067610482902501455504204433524520665822704844582452877416001060465891907497519632353148380799619,
+	0.0070186100094700966004070637388531825133772207289396032320082356192151241454178686953297376907573215077936155545790593837513204206518026084505878987243348925784479817181234617862457418214505322067610482902501455504204433524520665822704844582452877416001060465891907497519632353148380799619
+};
+
+#else
+
+/* n = 24 */
+
+static double T[] = {
+	-0.0640568928626056260850430826247450385909991954207473934243510817897392835939101078028928761342525090823242273835115756994869112500371756765277735374378372436515481804668409746233647956019276711845937319580510697455314397618513360822351096139837050674073737720614748330506959387258141490546,
+	0.0640568928626056260850430826247450385909991954207473934243510817897392835939101078028928761342525090823242273835115756994869112500371756765277735374378372436515481804668409746233647956019276711845937319580510697455314397618513360822351096139837050674073737720614748330506959387258141490546,
+	-0.1911188674736163091586398207570696318404051033147533561489185765880859526918717419824911112452097307135934146013595461392721542943443689459384015952736491888634107638852139839821480663334386199430823059446316182589874503457282270169922471283825305735240671464262733609193984099421023790425,
+	0.1911188674736163091586398207570696318404051033147533561489185765880859526918717419824911112452097307135934146013595461392721542943443689459384015952736491888634107638852139839821480663334386199430823059446316182589874503457282270169922471283825305735240671464262733609193984099421023790425,
+	-0.3150426796961633743867932913198102407864782608248172687542301295298821563412434083438735095552082106072251617364030643536658931791308690387340350108862316429911426633492164449851684039691011610681827256891467485494251442677599304969349712405008328365242087382043028815467866505618650936915,
+	0.3150426796961633743867932913198102407864782608248172687542301295298821563412434083438735095552082106072251617364030643536658931791308690387340350108862316429911426633492164449851684039691011610681827256891467485494251442677599304969349712405008328365242087382043028815467866505618650936915,
+	-0.4337935076260451384870842319133497124524215109279688080808012846567644070336309140577354304660756168836170633415002629755076381975174699198632370585889341378575229685577710965327823199539830928400741454067377627746745635503614810834602257701251585352190552527778684113280867150779959852524,
+	0.4337935076260451384870842319133497124524215109279688080808012846567644070336309140577354304660756168836170633415002629755076381975174699198632370585889341378575229685577710965327823199539830928400741454067377627746745635503614810834602257701251585352190552527778684113280867150779959852524,
+	-0.5454214713888395356583756172183723700107839925876181754336143898305648391795708970958348674408062501977746653313676778948810297400650828985504068941547021866808914316854182653519436295728612315264181208390018064915325250677148594855874434492614547180849377989457776201862945948751249939033,
+	0.5454214713888395356583756172183723700107839925876181754336143898305648391795708970958348674408062501977746653313676778948810297400650828985504068941547021866808914316854182653519436295728612315264181208390018064915325250677148594855874434492614547180849377989457776201862945948751249939033,
+	-0.6480936519369755692524957869107476266696582986189567802989336650244483175685397719281177703657272433990519954414744003453347794058626075519074876962003580684127104697893556584036149935275154534232685850207671594298434446955488396349075497667624732345971957611938685137884801129695447597312,
+	0.6480936519369755692524957869107476266696582986189567802989336650244483175685397719281177703657272433990519954414744003453347794058626075519074876962003580684127104697893556584036149935275154534232685850207671594298434446955488396349075497667624732345971957611938685137884801129695447597312,
+	-0.7401241915785543642438281030999784255232924870141854568663823682719003386409229324413313561311287943298526270745398288213617461973439599491355223046073660810109486527571776420522757185953076208759863287235084614803697918067466580746275122563457575959399650481778575563118955957829855078072,
+	0.7401241915785543642438281030999784255232924870141854568663823682719003386409229324413313561311287943298526270745398288213617461973439599491355223046073660810109486527571776420522757185953076208759863287235084614803697918067466580746275122563457575959399650481778575563118955957829855078072,
+	-0.8200019859739029219539498726697452080761264776678555872439810260013829789535545400822605211725837960666424765858309152369975956748693910897310401393217997751433463343851603146734984964062776585418194561809063555489816762580329418137298754264378316716417347949040725111554705589243953692169,
+	0.8200019859739029219539498726697452080761264776678555872439810260013829789535545400822605211725837960666424765858309152369975956748693910897310401393217997751433463343851603146734984964062776585418194561809063555489816762580329418137298754264378316716417347949040725111554705589243953692169,
+	-0.8864155270044010342131543419821967550873330433089200403710379167756748343989591721041235019961817012535295108910075024175885664874383567124270976139069615059721185542370372118538064873468961679956606315961988138722471292807573552657465373246065266349095264290446955886450980216411579068464,
+	0.8864155270044010342131543419821967550873330433089200403710379167756748343989591721041235019961817012535295108910075024175885664874383567124270976139069615059721185542370372118538064873468961679956606315961988138722471292807573552657465373246065266349095264290446955886450980216411579068464,
+	-0.9382745520027327585236490017087214496548196580774513466350271759095894960525356709599646415358699555094267057623515929895997449470704383076095012442349544937551633313675972481722466159802428487600880633341786121580661077521685134893546419567859808853944866142065617471979973235700469563606,
+	0.9382745520027327585236490017087214496548196580774513466350271759095894960525356709599646415358699555094267057623515929895997449470704383076095012442349544937551633313675972481722466159802428487600880633341786121580661077521685134893546419567859808853944866142065617471979973235700469563606,
+	-0.9747285559713094981983919930081690617411830530401787198115935651071811212809802245386374742817154549827412585755713491144798180281062083910290010368962899139003272102551955405455775700818480561392470581718221938768668731616756379649281934548623489251537698395239432800432811839537332490367,
+	0.9747285559713094981983919930081690617411830530401787198115935651071811212809802245386374742817154549827412585755713491144798180281062083910290010368962899139003272102551955405455775700818480561392470581718221938768668731616756379649281934548623489251537698395239432800432811839537332490367,
+	-0.9951872199970213601799974097007368118745976925960028774416005451142838320694577378833972893371157088623453462978965853994497237745715598401409351804188189455255566266162142239452364851560816782389596967291836243391359167365098731808888455424405665558369621091780571617968925046375452278564,
+	0.9951872199970213601799974097007368118745976925960028774416005451142838320694577378833972893371157088623453462978965853994497237745715598401409351804188189455255566266162142239452364851560816782389596967291836243391359167365098731808888455424405665558369621091780571617968925046375452278564,
+};
+
+static double C[] = {
+	0.1279381953467521569740561652246953718517112395416678824212995763723475915405364024120919775667347423307078678605027534354336365506630173201256407760369958705384835762891562911475479559477218918074170718365754182501974550951925484331523758090745471505157505768499921691572488912345533434646,
+	0.1279381953467521569740561652246953718517112395416678824212995763723475915405364024120919775667347423307078678605027534354336365506630173201256407760369958705384835762891562911475479559477218918074170718365754182501974550951925484331523758090745471505157505768499921691572488912345533434646,
+	0.1258374563468282961213753825111836887264033255813454041780915168813938726666625968820381792564211407244125340112283619371640023694354842556219623307075721695505167028832011944572440814161265754364153991752782846305315778293182951298508346824950922490384565834525141570991957343073460241123,
+	0.1258374563468282961213753825111836887264033255813454041780915168813938726666625968820381792564211407244125340112283619371640023694354842556219623307075721695505167028832011944572440814161265754364153991752782846305315778293182951298508346824950922490384565834525141570991957343073460241123,
+	0.1216704729278033912044631534762624256070295592038057787774717545126253937177169619177578034307728419129571458407698685455109927385962626203664197972099671299080663146992247474377374928428629909818345130957392521139337403891946990001210368274459006298591636884893163373907763429334385715701,
+	0.1216704729278033912044631534762624256070295592038057787774717545126253937177169619177578034307728419129571458407698685455109927385962626203664197972099671299080663146992247474377374928428629909818345130957392521139337403891946990001210368274459006298591636884893163373907763429334385715701,
+	0.1155056680537256013533444839067835598622703113764964705844493600886702535513185499403442576468127956599599096047023274406552399890629831050388267870570157536484442644788074009392626299528272339158271789101012709245867329169327356527615681351864802567093740938014246237226139721687821239517,
+	0.1155056680537256013533444839067835598622703113764964705844493600886702535513185499403442576468127956599599096047023274406552399890629831050388267870570157536484442644788074009392626299528272339158271789101012709245867329169327356527615681351864802567093740938014246237226139721687821239517,
+	0.107444270115965634782577342446606222794628690134220021766541640886821866394437105980586727120915236672945076498454815476823439901643102885282830543962266851556251956709331696682107380679861280071851870323872823740641856241992841364843152888380035317713347953732555881218806283399463124951,
+	0.107444270115965634782577342446606222794628690134220021766541640886821866394437105980586727120915236672945076498454815476823439901643102885282830543962266851556251956709331696682107380679861280071851870323872823740641856241992841364843152888380035317713347953732555881218806283399463124951,
+	0.097618652104113888269880664464247154427918968853685944083310610022954338577591978348020039690718187482414745713364268645676642419728572107043424944384211806071042042791689191672508012725933985685876262715739521302925263010913644942223616059647289160432915821120275634713911721781926285332,
+	0.097618652104113888269880664464247154427918968853685944083310610022954338577591978348020039690718187482414745713364268645676642419728572107043424944384211806071042042791689191672508012725933985685876262715739521302925263010913644942223616059647289160432915821120275634713911721781926285332,
+	0.0861901615319532759171852029837426671850805882379330055884071438612868844607805312688886562972816971732787465671984327992158782827038381983594380916492525003385563462630861694048857276454548529177279961693054540872738963763950131372564031674654030737773100525128451496727198421916322556908,
+	0.0861901615319532759171852029837426671850805882379330055884071438612868844607805312688886562972816971732787465671984327992158782827038381983594380916492525003385563462630861694048857276454548529177279961693054540872738963763950131372564031674654030737773100525128451496727198421916322556908,
+	0.0733464814110803057340336152531165181193365098484994714027024906600413884758709348323251422694445551958844309079341158927693012247996928526423877450601776912550600854944985229487704917122675007345403564777169078420148392438502785281584325129303566997853186794893103931008654660416023204965,
+	0.0733464814110803057340336152531165181193365098484994714027024906600413884758709348323251422694445551958844309079341158927693012247996928526423877450601776912550600854944985229487704917122675007345403564777169078420148392438502785281584325129303566997853186794893103931008654660416023204965,
+	0.0592985849154367807463677585001085845412001265652134910373765512940983031775082415660683556106090092998654733952492642466909653073834070291103432919838456250955380753837859345492817299145644958959367291816621761687898337760987530926613795554356869343124524696513178977787335055019515914172,
+	0.0592985849154367807463677585001085845412001265652134910373765512940983031775082415660683556106090092998654733952492642466909653073834070291103432919838456250955380753837859345492817299145644958959367291816621761687898337760987530926613795554356869343124524696513178977787335055019515914172,
+	0.0442774388174198061686027482113382288593128418338578967413972297210243762822664396343947170155594934934611803046066530352490769669525012630503089839091175520932522330681764807671830570648211944799908348398720715944900305481342571090714940628894962186599515560606956040614089479788668773348,
+	0.0442774388174198061686027482113382288593128418338578967413972297210243762822664396343947170155594934934611803046066530352490769669525012630503089839091175520932522330681764807671830570648211944799908348398720715944900305481342571090714940628894962186599515560606956040614089479788668773348,
+	0.0285313886289336631813078159518782864491977979319081166016648047576440056374291434256854254228098755422737224452711633426188506404779428430343631052424983978091405445557790206527391293478807818130301641760878492678184457761229065303399826533483010921962299302202888714000294545957159715602,
+	0.0285313886289336631813078159518782864491977979319081166016648047576440056374291434256854254228098755422737224452711633426188506404779428430343631052424983978091405445557790206527391293478807818130301641760878492678184457761229065303399826533483010921962299302202888714000294545957159715602,
+	0.0123412297999871995468056670700372915759100408913665168172873209410917255178811137917987186719204245118391668507179752021919736085531955203240536027970786521356478573832633493407323107496772162595516230980489700767963287958540270795597236457014112169997285946194632806836898378754527134097,
+	0.0123412297999871995468056670700372915759100408913665168172873209410917255178811137917987186719204245118391668507179752021919736085531955203240536027970786521356478573832633493407323107496772162595516230980489700767963287958540270795597236457014112169997285946194632806836898378754527134097,
+};
+
+#endif

gsk/gskcurveprivate.h

@@ -0,0 +1,189 @@
+/*
+ * Copyright © 2020 Benjamin Otte
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+
+#pragma once
+
+#include "gskpathopprivate.h"
+#include "gskpath.h"
+#include "gskboundingboxprivate.h"
+
+G_BEGIN_DECLS
+
+typedef gpointer gskpathop;
+
+typedef union _GskCurve GskCurve;
+
+typedef struct _GskLineCurve GskLineCurve;
+typedef struct _GskQuadCurve GskQuadCurve;
+typedef struct _GskCubicCurve GskCubicCurve;
+typedef struct _GskConicCurve GskConicCurve;
+
+struct _GskLineCurve
+{
+  GskPathOperation op;
+
+  gboolean padding;
+
+  graphene_point_t points[2];
+};
+
+struct _GskQuadCurve
+{
+  GskPathOperation op;
+
+  gboolean has_coefficients;
+
+  graphene_point_t points[3];
+
+  graphene_point_t coeffs[3];
+};
+
+struct _GskCubicCurve
+{
+  GskPathOperation op;
+
+  gboolean has_coefficients;
+
+  graphene_point_t points[4];
+
+  graphene_point_t coeffs[4];
+};
+
+struct _GskConicCurve
+{
+  GskPathOperation op;
+
+  gboolean has_coefficients;
+
+  /* points[0], points[1], points[3] are the control points,
+   * points[2].x is the weight
+   */
+  graphene_point_t points[4];
+
+  graphene_point_t num[3];
+  graphene_point_t denom[3];
+};
+
+union _GskCurve
+{
+  GskPathOperation op;
+  GskLineCurve line;
+  GskQuadCurve quad;
+  GskCubicCurve cubic;
+  GskConicCurve conic;
+};
+
+typedef enum {
+  GSK_CURVE_LINE_REASON_STRAIGHT,
+  GSK_CURVE_LINE_REASON_SHORT
+} GskCurveLineReason;
+
+typedef gboolean (* GskCurveAddLineFunc) (const graphene_point_t *from,
+                                          const graphene_point_t *to,
+                                          float                   from_progress,
+                                          float                   to_progress,
+                                          GskCurveLineReason      reason,
+                                          gpointer                user_data);
+
+typedef gboolean (* GskCurveAddCurveFunc) (GskPathOperation        op,
+                                           const graphene_point_t *pts,
+                                           gsize                   n_pts,
+                                           float                   weight,
+                                           gpointer                user_data);
+
+void                    gsk_curve_init                          (GskCurve               *curve,
+                                                                 gskpathop               op);
+void                    gsk_curve_init_foreach                  (GskCurve               *curve,
+                                                                 GskPathOperation        op,
+                                                                 const graphene_point_t *pts,
+                                                                 gsize                   n_pts,
+                                                                 float                   weight);
+
+void                    gsk_curve_print                         (const GskCurve         *curve,
+                                                                 GString                *string);
+
+char *                  gsk_curve_to_string                     (const GskCurve         *curve);
+
+gskpathop               gsk_curve_pathop                        (const GskCurve         *curve);
+const graphene_point_t *gsk_curve_get_start_point               (const GskCurve         *curve);
+const graphene_point_t *gsk_curve_get_end_point                 (const GskCurve         *curve);
+void                    gsk_curve_get_start_tangent             (const GskCurve         *curve,
+                                                                 graphene_vec2_t        *tangent);
+void                    gsk_curve_get_end_tangent               (const GskCurve         *curve,
+                                                                 graphene_vec2_t        *tangent);
+void                    gsk_curve_get_point                     (const GskCurve         *curve,
+                                                                 float                   progress,
+                                                                 graphene_point_t       *pos);
+void                    gsk_curve_get_tangent                   (const GskCurve         *curve,
+                                                                 float                   progress,
+                                                                 graphene_vec2_t        *tangent);
+void                    gsk_curve_reverse                       (const GskCurve         *curve,
+                                                                 GskCurve               *reverse);
+void                    gsk_curve_split                         (const GskCurve         *curve,
+                                                                 float                   progress,
+                                                                 GskCurve               *start,
+                                                                 GskCurve               *end);
+void                    gsk_curve_segment                       (const GskCurve         *curve,
+                                                                 float                   start,
+                                                                 float                   end,
+                                                                 GskCurve               *segment);
+gboolean                gsk_curve_decompose                     (const GskCurve         *curve,
+                                                                 float                   tolerance,
+                                                                 GskCurveAddLineFunc     add_line_func,
+                                                                 gpointer                user_data);
+gboolean                gsk_curve_decompose_curve               (const GskCurve         *curve,
+                                                                 GskPathForeachFlags     flags,
+                                                                 float                   tolerance,
+                                                                 GskCurveAddCurveFunc    add_curve_func,
+                                                                 gpointer                user_data);
+
+#define gsk_curve_builder_to(curve, builder) gsk_path_builder_pathop_to ((builder), gsk_curve_pathop (curve))
+
+float                   gsk_curve_get_curvature                 (const GskCurve         *curve,
+                                                                 float                   t,
+                                                                 graphene_point_t       *center);
+void                    gsk_curve_get_bounds                    (const GskCurve         *curve,
+                                                                 GskBoundingBox         *bounds);
+void                    gsk_curve_get_tight_bounds              (const GskCurve         *curve,
+                                                                 GskBoundingBox         *bounds);
+
+void                    gsk_curve_get_derivative_at             (const GskCurve         *curve,
+                                                                 float                   t,
+                                                                 graphene_point_t       *value);
+int                     gsk_curve_get_crossing                  (const GskCurve         *curve,
+                                                                 const graphene_point_t *point);
+gboolean                gsk_curve_get_closest_point             (const GskCurve         *curve,
+                                                                 const graphene_point_t *point,
+                                                                 float                   threshold,
+                                                                 float                  *out_dist,
+                                                                 float                  *out_t);
+float                  gsk_curve_get_length                     (const GskCurve         *curve);
+float                  gsk_curve_get_length_to                  (const GskCurve         *curve,
+                                                                 float                   t);
+float                  gsk_curve_at_length                      (const GskCurve         *curve,
+                                                                 float                   distance,
+                                                                 float                   epsilon);
+
+int                    gsk_curve_get_curvature_points           (const GskCurve *        curve,
+                                                                 float                   t[3]);
+
+
+G_END_DECLS
+

gsk/gskenums.h

@@ -1,5 +1,5 @@
 /* GSK - The GTK Scene Kit
- * Copyright 2016  Endless 
+ * Copyright 2016  Endless
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -51,7 +51,9 @@
  * @GSK_GL_SHADER_NODE: A node that uses OpenGL fragment shaders to render
  * @GSK_TEXTURE_SCALE_NODE: A node drawing a `GdkTexture` scaled and filtered (Since: 4.10)
  * @GSK_MASK_NODE: A node that masks one child with another (Since: 4.10)
- 
+ * @GSK_FILL_NODE: A node that fills a path
+ * @GSK_STROKE_NODE: A node that strokes a path
+
  * The type of a node determines what the node is rendering.
  */
 typedef enum {
@@ -82,7 +84,9 @@ typedef enum {
   GSK_DEBUG_NODE,
   GSK_GL_SHADER_NODE,
   GSK_TEXTURE_SCALE_NODE,
-  GSK_MASK_NODE
+  GSK_MASK_NODE,
+  GSK_FILL_NODE,
+  GSK_STROKE_NODE
 } GskRenderNodeType;
 
 /**
@@ -170,6 +174,164 @@ typedef enum {
   GSK_CORNER_BOTTOM_LEFT
 } GskCorner;
 
+/**
+ * GskFillRule:
+ * @GSK_FILL_RULE_WINDING: If the path crosses the ray from
+ *   left-to-right, counts +1. If the path crosses the ray
+ *   from right to left, counts -1. (Left and right are determined
+ *   from the perspective of looking along the ray from the starting
+ *   point.) If the total count is non-zero, the point will be filled.
+ * @GSK_FILL_RULE_EVEN_ODD: Counts the total number of
+ *   intersections, without regard to the orientation of the contour. If
+ *   the total number of intersections is odd, the point will be
+ *   filled.
+ *
+ * `GskFillRule` is used to select how paths are filled.
+ *
+ * Whether or not a point is included in the fill is determined by taking
+ * a ray from that point to infinity and looking at intersections with the
+ * path. The ray can be in any direction, as long as it doesn't pass through
+ * the end point of a segment or have a tricky intersection such as
+ * intersecting tangent to the path.
+ *
+ * (Note that filling is not actually implemented in this way. This
+ * is just a description of the rule that is applied.)
+ *
+ * New entries may be added in future versions.
+ *
+ * Since: 4.14
+ */
+typedef enum {
+  GSK_FILL_RULE_WINDING,
+  GSK_FILL_RULE_EVEN_ODD
+} GskFillRule;
+
+/**
+ * GskLineCap:
+ * @GSK_LINE_CAP_BUTT: Start and stop the line exactly at the start
+ *   and end point
+ * @GSK_LINE_CAP_ROUND: Use a round ending, the center of the circle
+ *   is the start or end point
+ * @GSK_LINE_CAP_SQUARE: use squared ending, the center of the square
+ *   is the start or end point
+ *
+ * Specifies how to render the start and end points of contours or
+ * dashes when stroking.
+ *
+ * The default line cap style is `GSK_LINE_CAP_BUTT`.
+ *
+ * New entries may be added in future versions.
+ *
+ * <figure>
+ *   <picture>
+ *     <source srcset="caps-dark.png" media="(prefers-color-scheme: dark)">
+ *     <img alt="Line Cap Styles" src="caps-light.png">
+ *   </picture>
+ *   <figcaption>GSK_LINE_CAP_BUTT, GSK_LINE_CAP_ROUND, GSK_LINE_CAP_SQUARE</figcaption>
+ * </figure>
+ *
+ * Since: 4.14
+ */
+typedef enum {
+  GSK_LINE_CAP_BUTT,
+  GSK_LINE_CAP_ROUND,
+  GSK_LINE_CAP_SQUARE
+} GskLineCap;
+
+/**
+ * GskLineJoin:
+ * @GSK_LINE_JOIN_MITER: Use a sharp angled corner
+ * @GSK_LINE_JOIN_ROUND: Use a round join, the center of the circle is
+ *   the join point
+ * @GSK_LINE_JOIN_BEVEL: use a cut-off join, the join is cut off at half
+ *   the line width from the joint point
+ *
+ * Specifies how to render the junction of two lines when stroking.
+ *
+ * The default line join style is `GSK_LINE_JOIN_MITER`.
+ *
+ * New entries may be added in future versions.
+ *
+ * <figure>
+ *   <picture>
+ *     <source srcset="join-dark.png" media="(prefers-color-scheme: dark)">
+ *     <img alt="Line Join Styles" src="join-light.png">
+ *   </picture>
+ *   <figcaption>GSK_LINE_JOINT_MITER, GSK_LINE_JOINT_ROUND, GSK_LINE_JOIN_BEVEL</figcaption>
+ * </figure>
+ *
+ * Since: 4.14
+ */
+typedef enum {
+  GSK_LINE_JOIN_MITER,
+  GSK_LINE_JOIN_ROUND,
+  GSK_LINE_JOIN_BEVEL,
+} GskLineJoin;
+
+/**
+ * GskPathOperation:
+ * @GSK_PATH_MOVE: A move-to operation, with 1 point describing the target point.
+ * @GSK_PATH_CLOSE: A close operation ending the current contour with a line back
+ *   to the starting point. Two points describe the start and end of the line.
+ * @GSK_PATH_LINE: A line-to operation, with 2 points describing the start and
+ *   end point of a straight line.
+ * @GSK_PATH_QUAD: A curve-to operation describing a quadratic Bézier curve
+ *   with 3 points describing the start point, the control point and the end
+ *   point of the curve.
+ * @GSK_PATH_CUBIC: A curve-to operation describing a cubic Bézier curve with 4
+ *   points describing the start point, the two control points and the end point
+ *   of the curve.
+ * @GSK_PATH_CONIC: A rational quadratic Bézier curve with 3 points describing
+ *   the start point, control point and end point of the curve. A weight for the
+ *   curve will be passed, too.
+ *
+ * Path operations are used to describe the segments of a `GskPath`.
+ *
+ * More values may be added in the future.
+ *
+ * Since: 4.14
+ */
+typedef enum {
+  GSK_PATH_MOVE,
+  GSK_PATH_CLOSE,
+  GSK_PATH_LINE,
+  GSK_PATH_QUAD,
+  GSK_PATH_CUBIC,
+  GSK_PATH_CONIC,
+} GskPathOperation;
+
+/**
+ * GskPathDirection:
+ * @GSK_PATH_FROM_START: The tangent in path direction of the incoming side
+ *   of the path
+ * @GSK_PATH_TO_START: The tangent against path direction of the incoming side
+ *   of the path
+ * @GSK_PATH_TO_END: The tangent in path direction of the outgoing side
+ *   of the path
+ * @GSK_PATH_FROM_END: The tangent against path direction of the outgoing
+ *   side of the path
+ *
+ * The values of the `GskPathDirection` enum are used to pick one
+ * of the four tangents at a given point on the path.
+ *
+ * Note that the directions for @GSK_PATH_FROM_START/@GSK_PATH_TO_END and
+ * @GSK_PATH_TO_START/@GSK_PATH_FROM_END will coincide for smooth points.
+ * Only sharp turns will exhibit four different directions.
+ *
+ * <picture>
+ *   <source srcset="directions-dark.png" media="(prefers-color-scheme: dark)">
+ *   <img alt="Path Tangents" src="directions-light.png">
+ * </picture>
+ *
+ * Since: 4.14
+ */
+typedef enum {
+  GSK_PATH_FROM_START,
+  GSK_PATH_TO_START,
+  GSK_PATH_TO_END,
+  GSK_PATH_FROM_END,
+} GskPathDirection;
+
 /**
  * GskSerializationError:
  * @GSK_SERIALIZATION_UNSUPPORTED_FORMAT: The format can not be identified
@@ -274,4 +436,3 @@ typedef enum
   GSK_MASK_MODE_LUMINANCE,
   GSK_MASK_MODE_INVERTED_LUMINANCE
 } GskMaskMode;
-

gsk/gskpath.h

@@ -0,0 +1,155 @@
+/*
+ * Copyright © 2020 Benjamin Otte
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+#pragma once
+
+#if !defined (__GSK_H_INSIDE__) && !defined (GTK_COMPILATION)
+#error "Only <gsk/gsk.h> can be included directly."
+#endif
+
+
+#include <gsk/gsktypes.h>
+
+G_BEGIN_DECLS
+
+/**
+ * GskPathForeachFlags:
+ * @GSK_PATH_FOREACH_ALLOW_ONLY_LINES: The default behavior, only allow lines.
+ * @GSK_PATH_FOREACH_ALLOW_QUAD: Allow emission of `GSK_PATH_QUAD` operations
+ * @GSK_PATH_FOREACH_ALLOW_CUBIC: Allow emission of `GSK_PATH_CUBIC` operations.
+ * @GSK_PATH_FOREACH_ALLOW_CONIC: Allow emission of `GSK_PATH_CONIC` operations.
+ *
+ * Flags that can be passed to gsk_path_foreach() to influence what
+ * kinds of operations the path is decomposed into.
+ *
+ * By default, [method@Gsk.Path.foreach] will only emit a path with all
+ * operations flattened to straight lines to allow for maximum compatibility.
+ * The only operations emitted will be `GSK_PATH_MOVE`, `GSK_PATH_LINE` and
+ * `GSK_PATH_CLOSE`.
+ *
+ * Since: 4.14
+ */
+typedef enum
+{
+  GSK_PATH_FOREACH_ALLOW_ONLY_LINES = 0,
+  GSK_PATH_FOREACH_ALLOW_QUAD       = (1 << 0),
+  GSK_PATH_FOREACH_ALLOW_CUBIC      = (1 << 1),
+  GSK_PATH_FOREACH_ALLOW_CONIC      = (1 << 2),
+} GskPathForeachFlags;
+
+/**
+ * GskPathForeachFunc:
+ * @op: The operation
+ * @pts: The points of the operation
+ * @n_pts: The number of points
+ * @weight: The weight for conic curves, or unused if not a conic curve
+ * @user_data: The user data provided with the function
+ *
+ * Prototype of the callback to iterate through the operations of
+ * a path.
+ *
+ * For each operation, the callback is given the @op itself, the points
+ * that the operation is applied to in @pts, and a @weight for conic
+ * curves. The @n_pts argument is somewhat redundant, since the number
+ * of points can be inferred from the operation.
+ *
+ * Each contour of the path starts with a @GSK_PATH_MOVE operation.
+ * Closed contours end with a @GSK_PATH_CLOSE operation.
+ *
+ * Returns: %TRUE to continue iterating the path, %FALSE to
+ *   immediately abort and not call the function again.
+ */
+typedef gboolean (* GskPathForeachFunc) (GskPathOperation        op,
+                                         const graphene_point_t *pts,
+                                         gsize                   n_pts,
+                                         float                   weight,
+                                         gpointer                user_data);
+
+#define GSK_TYPE_PATH (gsk_path_get_type ())
+
+GDK_AVAILABLE_IN_4_14
+GType                   gsk_path_get_type                       (void) G_GNUC_CONST;
+
+GDK_AVAILABLE_IN_4_14
+GskPath *               gsk_path_ref                            (GskPath                *self);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_unref                          (GskPath                *self);
+
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_print                          (GskPath                *self,
+                                                                 GString                *string);
+GDK_AVAILABLE_IN_4_14
+char *                  gsk_path_to_string                      (GskPath                *self);
+
+GDK_AVAILABLE_IN_4_14
+GskPath *               gsk_path_parse                          (const char             *string);
+
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_to_cairo                       (GskPath                *self,
+                                                                 cairo_t                *cr);
+
+GDK_AVAILABLE_IN_4_14
+gboolean                gsk_path_is_empty                       (GskPath                *self);
+
+GDK_AVAILABLE_IN_4_14
+gboolean                gsk_path_is_closed                      (GskPath                *self);
+
+GDK_AVAILABLE_IN_4_14
+gboolean                gsk_path_get_bounds                     (GskPath                *self,
+                                                                 graphene_rect_t        *bounds);
+
+GDK_AVAILABLE_IN_4_14
+gboolean                gsk_path_get_stroke_bounds              (GskPath                *self,
+                                                                 const GskStroke        *stroke,
+                                                                 graphene_rect_t        *bounds);
+
+GDK_AVAILABLE_IN_4_14
+gboolean                gsk_path_in_fill                        (GskPath                *self,
+                                                                 const graphene_point_t *point,
+                                                                 GskFillRule             fill_rule);
+
+GDK_AVAILABLE_IN_4_14
+gboolean                gsk_path_get_start_point                (GskPath                *self,
+                                                                 GskPathPoint           *result);
+GDK_AVAILABLE_IN_4_14
+gboolean                gsk_path_get_end_point                  (GskPath                *self,
+                                                                 GskPathPoint           *result);
+
+GDK_AVAILABLE_IN_4_14
+gboolean                gsk_path_get_closest_point              (GskPath                *self,
+                                                                 const graphene_point_t *point,
+                                                                 float                   threshold,
+                                                                 GskPathPoint           *result,
+                                                                 float                  *distance);
+
+GDK_AVAILABLE_IN_4_14
+gboolean                gsk_path_foreach                        (GskPath                *self,
+                                                                 GskPathForeachFlags     flags,
+                                                                 GskPathForeachFunc      func,
+                                                                 gpointer                user_data);
+
+GDK_AVAILABLE_IN_4_14
+gboolean                gsk_path_dash                           (GskPath                *self,
+                                                                 GskStroke              *stroke,
+                                                                 GskPathForeachFunc      func,
+                                                                 gpointer                user_data);
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(GskPath, gsk_path_unref)
+
+G_END_DECLS

gsk/gskpathbuilder.h

@@ -0,0 +1,192 @@
+/*
+ * Copyright © 2020 Benjamin Otte
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+#pragma once
+
+#if !defined (__GSK_H_INSIDE__) && !defined (GTK_COMPILATION)
+#error "Only <gsk/gsk.h> can be included directly."
+#endif
+
+
+#include <gsk/gskroundedrect.h>
+#include <gsk/gsktypes.h>
+
+G_BEGIN_DECLS
+
+#define GSK_TYPE_PATH_BUILDER (gsk_path_builder_get_type ())
+
+GDK_AVAILABLE_IN_4_14
+GType                   gsk_path_builder_get_type               (void) G_GNUC_CONST;
+
+GDK_AVAILABLE_IN_4_14
+GskPathBuilder *        gsk_path_builder_new                    (void);
+GDK_AVAILABLE_IN_4_14
+GskPathBuilder *        gsk_path_builder_ref                    (GskPathBuilder         *self);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_unref                  (GskPathBuilder         *self);
+GDK_AVAILABLE_IN_4_14
+GskPath *               gsk_path_builder_free_to_path           (GskPathBuilder         *self) G_GNUC_WARN_UNUSED_RESULT;
+GDK_AVAILABLE_IN_4_14
+GskPath *               gsk_path_builder_to_path                (GskPathBuilder         *self) G_GNUC_WARN_UNUSED_RESULT;
+
+GDK_AVAILABLE_IN_4_14
+const graphene_point_t *gsk_path_builder_get_current_point      (GskPathBuilder         *self);
+
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_add_path               (GskPathBuilder         *self,
+                                                                 GskPath                *path);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_add_reverse_path       (GskPathBuilder         *self,
+                                                                 GskPath                *path);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_add_cairo_path         (GskPathBuilder         *self,
+                                                                 const cairo_path_t     *path);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_add_layout             (GskPathBuilder         *self,
+                                                                 PangoLayout            *layout);
+
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_add_rect               (GskPathBuilder         *self,
+                                                                 const graphene_rect_t  *rect);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_add_rounded_rect       (GskPathBuilder         *self,
+                                                                 const GskRoundedRect   *rect);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_add_circle             (GskPathBuilder         *self,
+                                                                 const graphene_point_t *center,
+                                                                 float                   radius);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_add_segment            (GskPathBuilder         *self,
+                                                                 GskPath                *path,
+                                                                 const GskPathPoint     *start,
+                                                                 const GskPathPoint     *end);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_move_to                (GskPathBuilder         *self,
+                                                                 float                   x,
+                                                                 float                   y);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_rel_move_to            (GskPathBuilder         *self,
+                                                                 float                   x,
+                                                                 float                   y);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_line_to                (GskPathBuilder         *self,
+                                                                 float                   x,
+                                                                 float                   y);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_rel_line_to            (GskPathBuilder         *self,
+                                                                 float                   x,
+                                                                 float                   y);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_quad_to                (GskPathBuilder         *self,
+                                                                 float                   x1,
+                                                                 float                   y1,
+                                                                 float                   x2,
+                                                                 float                   y2);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_rel_quad_to            (GskPathBuilder         *self,
+                                                                 float                   x1,
+                                                                 float                   y1,
+                                                                 float                   x2,
+                                                                 float                   y2);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_cubic_to               (GskPathBuilder         *self,
+                                                                 float                   x1,
+                                                                 float                   y1,
+                                                                 float                   x2,
+                                                                 float                   y2,
+                                                                 float                   x3,
+                                                                 float                   y3);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_rel_cubic_to           (GskPathBuilder         *self,
+                                                                 float                   x1,
+                                                                 float                   y1,
+                                                                 float                   x2,
+                                                                 float                   y2,
+                                                                 float                   x3,
+                                                                 float                   y3);
+
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_conic_to               (GskPathBuilder         *self,
+                                                                 float                   x1,
+                                                                 float                   y1,
+                                                                 float                   x2,
+                                                                 float                   y2,
+                                                                 float                   weight);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_rel_conic_to           (GskPathBuilder         *self,
+                                                                 float                   x1,
+                                                                 float                   y1,
+                                                                 float                   x2,
+                                                                 float                   y2,
+                                                                 float                   weight);
+
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_arc_to                 (GskPathBuilder         *self,
+                                                                 float                   x1,
+                                                                 float                   y1,
+                                                                 float                   x2,
+                                                                 float                   y2);
+
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_rel_arc_to             (GskPathBuilder         *self,
+                                                                 float                   x1,
+                                                                 float                   y1,
+                                                                 float                   x2,
+                                                                 float                   y2);
+
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_svg_arc_to             (GskPathBuilder         *self,
+                                                                 float                   rx,
+                                                                 float                   ry,
+                                                                 float                   x_axis_rotation,
+                                                                 gboolean                large_arc,
+                                                                 gboolean                positive_sweep,
+                                                                 float                   x,
+                                                                 float                   y);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_rel_svg_arc_to         (GskPathBuilder         *self,
+                                                                 float                   rx,
+                                                                 float                   ry,
+                                                                 float                   x_axis_rotation,
+                                                                 gboolean                large_arc,
+                                                                 gboolean                positive_sweep,
+                                                                 float                   x,
+                                                                 float                   y);
+
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_html_arc_to            (GskPathBuilder         *self,
+                                                                 float                   x1,
+                                                                 float                   y1,
+                                                                 float                   x2,
+                                                                 float                   y2,
+                                                                 float                   radius);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_rel_html_arc_to        (GskPathBuilder         *self,
+                                                                 float                   x1,
+                                                                 float                   y1,
+                                                                 float                   x2,
+                                                                 float                   y2,
+                                                                 float                   radius);
+
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_builder_close                  (GskPathBuilder         *self);
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(GskPathBuilder, gsk_path_builder_unref)
+
+G_END_DECLS

gsk/gskpathdash.c

@@ -0,0 +1,280 @@
+/*
+ * Copyright © 2020 Benjamin Otte
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+#include "config.h"
+
+#include "gskcontourprivate.h"
+#include "gskcurveprivate.h"
+#include "gskpathprivate.h"
+#include "gskstrokeprivate.h"
+
+typedef struct
+{
+  float offset;                 /* how much of the current dash we've spent */
+  gsize dash_index;             /* goes from 0 to n_dash * 2, so we don't have to care about on/off
+                                 * for uneven dashes
+                                 */
+  gboolean on;                  /* If we're currently dashing or not */
+  gboolean may_close;           /* TRUE if we haven't turned the dash off in this contour */
+  gboolean needs_move_to;       /* If we have emitted the initial move_to() yet */
+  enum {
+    NORMAL, /* no special behavior required */
+    SKIP,   /* skip the next dash */
+    ONLY,   /* only do the first dash */
+    DONE    /* done with the first dash */
+  } first_dash_behavior;        /* How to handle the first dash in the loop. We loop closed contours
+                                 * twice to make sure the first dash and the last dash can get joined
+                                 */
+  float collect_start;          /* We're collecting multiple line segments when decomposing. */
+
+  /* from the stroke */
+  float *dash;
+  gsize n_dash;
+  float dash_length;
+  float dash_offset;
+
+  GskPathForeachFunc func;
+  gpointer user_data;
+} GskPathDash;
+
+static void
+gsk_path_dash_setup (GskPathDash *self)
+{
+  self->offset = fmodf (self->dash_offset, 2 * self->dash_length);
+
+  self->dash_index = 0;
+  self->on = TRUE;
+  self->may_close = TRUE;
+  while (self->offset > self->dash[self->dash_index % self->n_dash])
+    {
+      self->offset -= self->dash[self->dash_index % self->n_dash];
+      self->dash_index++;
+      self->on = !self->on;
+    }
+  if (self->first_dash_behavior != ONLY)
+    self->needs_move_to = TRUE;
+}
+
+static gboolean
+gsk_path_dash_ensure_move_to (GskPathDash            *self,
+                              const graphene_point_t *pt)
+{
+  if (!self->needs_move_to)
+    return TRUE;
+
+  if (!self->func (GSK_PATH_MOVE, pt, 1, 0.f, self->user_data))
+    return FALSE;
+
+  self->needs_move_to = FALSE;
+  return TRUE;
+}
+
+static gboolean
+gsk_path_dash_add_curve (const GskCurve *curve,
+                         GskPathDash    *self)
+{
+  float remaining, t_start, t_end;
+  float used;
+
+  remaining = gsk_curve_get_length (curve);
+  used = 0;
+  t_start = 0;
+
+  while (remaining > 0)
+    {
+      float piece;
+
+      if (self->offset + remaining <= self->dash[self->dash_index % self->n_dash])
+        piece = remaining;
+      else
+        piece = self->dash[self->dash_index % self->n_dash] - self->offset;
+
+      t_end = gsk_curve_at_length (curve, used + piece, 0.001);
+
+      if (self->on)
+        {
+          if (self->first_dash_behavior != SKIP)
+            {
+              GskCurve segment;
+
+              if (piece > 0)
+                {
+                  gsk_curve_segment (curve, t_start, t_end, &segment);
+                  if (!gsk_path_dash_ensure_move_to (self, gsk_curve_get_start_point (&segment)))
+                    return FALSE;
+
+                  if (!gsk_pathop_foreach (gsk_curve_pathop (&segment), self->func, self->user_data))
+                    return FALSE;
+                }
+              else
+                {
+                  graphene_point_t p;
+
+                  gsk_curve_get_point (curve, t_start, &p);
+                  if (!gsk_path_dash_ensure_move_to (self, &p))
+                    return FALSE;
+                }
+            }
+        }
+      else
+        {
+          self->may_close = FALSE;
+          if (self->first_dash_behavior == ONLY)
+            {
+              self->first_dash_behavior = DONE;
+              return FALSE;
+            }
+          self->first_dash_behavior = NORMAL;
+        }
+
+      if (self->offset + remaining <= self->dash[self->dash_index % self->n_dash])
+        {
+          self->offset += remaining;
+          remaining = 0;
+        }
+      else
+        {
+          t_start = t_end;
+          remaining -= piece;
+          used += piece;
+          self->offset = 0;
+          self->dash_index++;
+          self->dash_index %= 2 * self->n_dash;
+          self->on = !self->on;
+          self->needs_move_to = TRUE;
+        }
+    }
+
+  return TRUE;
+}
+
+static gboolean
+gsk_path_dash_foreach (GskPathOperation        op,
+                       const graphene_point_t *pts,
+                       gsize                   n_pts,
+                       float                   weight,
+                       gpointer                user_data)
+{
+  GskPathDash *self = user_data;
+  GskCurve curve;
+
+  switch (op)
+  {
+    case GSK_PATH_MOVE:
+      gsk_path_dash_setup (self);
+      break;
+
+    case GSK_PATH_CLOSE:
+      if (self->may_close)
+        {
+          if (graphene_point_equal (&pts[0], &pts[1]))
+            return self->func (GSK_PATH_CLOSE, pts, 2, weight, self->user_data);
+        }
+      else
+        op = GSK_PATH_LINE;
+      G_GNUC_FALLTHROUGH;
+
+    case GSK_PATH_LINE:
+    case GSK_PATH_QUAD:
+    case GSK_PATH_CUBIC:
+    case GSK_PATH_CONIC:
+      gsk_curve_init_foreach (&curve, op, pts, n_pts, weight);
+      if (!gsk_path_dash_add_curve (&curve, self))
+        return FALSE;
+      break;
+
+    default:
+      g_assert_not_reached ();
+      break;
+  }
+
+  return TRUE;
+}
+
+gboolean
+gsk_contour_dash (const GskContour   *contour,
+                  GskStroke          *stroke,
+                  GskPathForeachFunc  func,
+                  gpointer            user_data)
+{
+  GskPathDash self = {
+    .offset = 0,
+    .dash = stroke->dash,
+    .n_dash = stroke->n_dash,
+    .dash_length = stroke->dash_length,
+    .dash_offset = stroke->dash_offset,
+    .func = func,
+    .user_data = user_data
+  };
+  gboolean is_closed = gsk_contour_get_flags (contour) & GSK_PATH_CLOSED ? TRUE : FALSE;
+
+  self.first_dash_behavior = is_closed ? SKIP : NORMAL;
+  if (!gsk_contour_foreach (contour, gsk_path_dash_foreach, &self))
+    return FALSE;
+
+  if (is_closed)
+    {
+      if (self.first_dash_behavior == NORMAL)
+        self.first_dash_behavior = ONLY;
+      else
+        self.first_dash_behavior = NORMAL;
+      self.needs_move_to = !self.on;
+      if (!gsk_contour_foreach (contour, gsk_path_dash_foreach, &self) &&
+          self.first_dash_behavior != DONE)
+        return FALSE;
+    }
+
+  return TRUE;
+}
+
+/**
+ * gsk_path_dash:
+ * @self: the `GskPath` to dash
+ * @stroke: the stroke containing the dash parameters
+ * @func: (scope call) (closure user_data): the function to call for operations
+ * @user_data: (nullable): user data passed to @func
+ *
+ * Calls @func for every operation of the path that is the result
+ * of dashing @self with the dash pattern from @stroke.
+ *
+ * Returns: `FALSE` if @func returned FALSE`, `TRUE` otherwise.
+ *
+ * Since: 4.14
+ */
+gboolean
+gsk_path_dash (GskPath            *self,
+               GskStroke          *stroke,
+               GskPathForeachFunc  func,
+               gpointer            user_data)
+{
+  gsize i;
+
+  /* Dashing disabled, no need to do any work */
+  if (stroke->dash_length <= 0)
+    return gsk_path_foreach (self, -1, func, user_data);
+
+  for (i = 0; i < gsk_path_get_n_contours (self); i++)
+    {
+      if (!gsk_contour_dash (gsk_path_get_contour (self, i), stroke, func, user_data))
+        return FALSE;
+    }
+
+  return TRUE;
+}
+

gsk/gskpathmeasure.c

@@ -0,0 +1,328 @@
+/*
+ * Copyright © 2020 Benjamin Otte
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+#include "config.h"
+
+#include "gskpathmeasure.h"
+
+#include "gskpathbuilder.h"
+#include "gskpathpointprivate.h"
+#include "gskcontourprivate.h"
+#include "gskpathprivate.h"
+
+/**
+ * GskPathMeasure:
+ *
+ * `GskPathMeasure` is an object that allows measurements
+ * on `GskPath`s such as determining the length of the path.
+ *
+ * Many measuring operations require sampling the path length
+ * at intermediate points. Therefore, a `GskPathMeasure` has
+ * a tolerance that determines what precision is required
+ * for such approximations.
+ *
+ * A `GskPathMeasure` struct is a reference counted struct
+ * and should be treated as opaque.
+ *
+ * Since: 4.14
+ */
+
+typedef struct _GskContourMeasure GskContourMeasure;
+
+struct _GskContourMeasure
+{
+  float length;
+  gpointer contour_data;
+};
+
+struct _GskPathMeasure
+{
+  /*< private >*/
+  guint ref_count;
+
+  GskPath *path;
+  float tolerance;
+
+  float length;
+  gsize n_contours;
+  GskContourMeasure measures[];
+};
+
+G_DEFINE_BOXED_TYPE (GskPathMeasure, gsk_path_measure,
+                     gsk_path_measure_ref,
+                     gsk_path_measure_unref)
+
+/**
+ * gsk_path_measure_new:
+ * @path: the path to measure
+ *
+ * Creates a measure object for the given @path with the
+ * default tolerance.
+ *
+ * Returns: a new `GskPathMeasure` representing @path
+ *
+ * Since: 4.14
+ */
+GskPathMeasure *
+gsk_path_measure_new (GskPath *path)
+{
+  return gsk_path_measure_new_with_tolerance (path, GSK_PATH_TOLERANCE_DEFAULT);
+}
+
+/**
+ * gsk_path_measure_new_with_tolerance:
+ * @path: the path to measure
+ * @tolerance: the tolerance for measuring operations
+ *
+ * Creates a measure object for the given @path and @tolerance.
+ *
+ * Returns: a new `GskPathMeasure` representing @path
+ *
+ * Since: 4.14
+ */
+GskPathMeasure *
+gsk_path_measure_new_with_tolerance (GskPath *path,
+                                     float    tolerance)
+{
+  GskPathMeasure *self;
+  gsize i, n_contours;
+
+  g_return_val_if_fail (path != NULL, NULL);
+  g_return_val_if_fail (tolerance > 0, NULL);
+
+  n_contours = gsk_path_get_n_contours (path);
+
+  self = g_malloc0 (sizeof (GskPathMeasure) + n_contours * sizeof (GskContourMeasure));
+
+  self->ref_count = 1;
+  self->path = gsk_path_ref (path);
+  self->tolerance = tolerance;
+  self->n_contours = n_contours;
+
+  for (i = 0; i < n_contours; i++)
+    {
+      self->measures[i].contour_data = gsk_contour_init_measure (gsk_path_get_contour (path, i),
+                                                                 self->tolerance,
+                                                                 &self->measures[i].length);
+      self->length += self->measures[i].length;
+    }
+
+  return self;
+}
+
+/**
+ * gsk_path_measure_ref:
+ * @self: a `GskPathMeasure`
+ *
+ * Increases the reference count of a `GskPathMeasure` by one.
+ *
+ * Returns: the passed in `GskPathMeasure`.
+ *
+ * Since: 4.14
+ */
+GskPathMeasure *
+gsk_path_measure_ref (GskPathMeasure *self)
+{
+  g_return_val_if_fail (self != NULL, NULL);
+
+  self->ref_count++;
+
+  return self;
+}
+
+/**
+ * gsk_path_measure_unref:
+ * @self: a `GskPathMeasure`
+ *
+ * Decreases the reference count of a `GskPathMeasure` by one.
+ *
+ * If the resulting reference count is zero, frees the object.
+ *
+ * Since: 4.14
+ */
+void
+gsk_path_measure_unref (GskPathMeasure *self)
+{
+  gsize i;
+
+  g_return_if_fail (self != NULL);
+  g_return_if_fail (self->ref_count > 0);
+
+  self->ref_count--;
+  if (self->ref_count > 0)
+    return;
+
+  for (i = 0; i < self->n_contours; i++)
+    {
+      gsk_contour_free_measure (gsk_path_get_contour (self->path, i),
+                                self->measures[i].contour_data);
+    }
+
+  gsk_path_unref (self->path);
+  g_free (self);
+}
+
+/**
+ * gsk_path_measure_get_path:
+ * @self: a `GskPathMeasure`
+ *
+ * Returns the path that the measure was created for.
+ *
+ * Returns: (transfer none): the path of @self
+ *
+ * Since: 4.14
+ */
+GskPath *
+gsk_path_measure_get_path (GskPathMeasure *self)
+{
+  return self->path;
+}
+
+/**
+ * gsk_path_measure_get_tolerance:
+ * @self: a `GskPathMeasure`
+ *
+ * Returns the tolerance that the measure was created with.
+ *
+ * Returns: the tolerance of @self
+ *
+ * Since: 4.14
+ */
+float
+gsk_path_measure_get_tolerance (GskPathMeasure *self)
+{
+  return self->tolerance;
+}
+
+/**
+ * gsk_path_measure_get_length:
+ * @self: a `GskPathMeasure`
+ *
+ * Gets the length of the path being measured.
+ *
+ * The length is cached, so this function does not do any work.
+ *
+ * Returns: The length of the path measured by @self
+ *
+ * Since: 4.14
+ */
+float
+gsk_path_measure_get_length (GskPathMeasure *self)
+{
+  g_return_val_if_fail (self != NULL, 0);
+
+  return self->length;
+}
+
+static float
+gsk_path_measure_clamp_distance (GskPathMeasure *self,
+                                 float           distance)
+{
+  if (isnan (distance))
+    return 0;
+
+  return CLAMP (distance, 0, self->length);
+}
+
+/**
+ * gsk_path_measure_get_point:
+ * @self: a `GskPathMeasure`
+ * @distance: the distance
+ * @result: (out caller-allocates): return location for the result
+ *
+ * Sets @result to the point at the given distance into the path.
+ *
+ * An empty path has no points, so `FALSE` is returned in that case.
+ *
+ * Returns: `TRUE` if @result was set
+ *
+ * Since: 4.14
+ */
+gboolean
+gsk_path_measure_get_point (GskPathMeasure *self,
+                            float           distance,
+                            GskPathPoint   *result)
+{
+  gsize i;
+  const GskContour *contour;
+
+  g_return_val_if_fail (self != NULL, FALSE);
+  g_return_val_if_fail (result != NULL, FALSE);
+
+  if (self->n_contours == 0)
+    return FALSE;
+
+  distance = gsk_path_measure_clamp_distance (self, distance);
+
+  for (i = 0; i < self->n_contours - 1; i++)
+    {
+      if (distance < self->measures[i].length)
+        break;
+
+      distance -= self->measures[i].length;
+    }
+
+  g_assert (0 <= i && i < self->n_contours);
+
+  distance = CLAMP (distance, 0, self->measures[i].length);
+
+  contour = gsk_path_get_contour (self->path, i);
+
+  gsk_contour_get_point (contour, self->measures[i].contour_data, distance, result);
+
+  g_assert (0 <= result->t && result->t <= 1);
+
+  result->contour = i;
+
+  return TRUE;
+}
+
+/**
+ * gsk_path_point_get_distance:
+ * @point: a `GskPathPoint on the path
+ * @measure: a `GskPathMeasure` for the path
+ *
+ * Returns the distance from the beginning of the path
+ * to @point.
+ *
+ * Returns: the distance of @point
+ *
+ * Since: 4.14
+ */
+float
+gsk_path_point_get_distance (const GskPathPoint *point,
+                             GskPathMeasure     *measure)
+{
+  float contour_offset = 0;
+
+  g_return_val_if_fail (measure != NULL, 0);
+  g_return_val_if_fail (gsk_path_point_valid (point, measure->path), 0);
+
+  for (gsize i = 0; i < measure->n_contours; i++)
+    {
+      if (i == point->contour)
+        return contour_offset + gsk_contour_get_distance (gsk_path_get_contour (measure->path, i),
+                                                          point,
+                                                          measure->measures[i].contour_data);
+
+      contour_offset += measure->measures[i].length;
+    }
+
+  g_return_val_if_reached (0);
+}

gsk/gskpathmeasure.h

@@ -0,0 +1,62 @@
+/*
+ * Copyright © 2020 Benjamin Otte
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+#pragma once
+
+#if !defined (__GSK_H_INSIDE__) && !defined (GTK_COMPILATION)
+#error "Only <gsk/gsk.h> can be included directly."
+#endif
+
+
+#include <gsk/gskpath.h>
+#include <gsk/gskpathpoint.h>
+
+G_BEGIN_DECLS
+
+#define GSK_TYPE_PATH_MEASURE (gsk_path_measure_get_type ())
+
+GDK_AVAILABLE_IN_4_14
+GType                   gsk_path_measure_get_type               (void) G_GNUC_CONST;
+GDK_AVAILABLE_IN_4_14
+GskPathMeasure *        gsk_path_measure_new                    (GskPath                *path);
+GDK_AVAILABLE_IN_4_14
+GskPathMeasure *        gsk_path_measure_new_with_tolerance     (GskPath                *path,
+                                                                 float                   tolerance);
+
+GDK_AVAILABLE_IN_4_14
+GskPathMeasure *        gsk_path_measure_ref                    (GskPathMeasure         *self);
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_measure_unref                  (GskPathMeasure         *self);
+
+GDK_AVAILABLE_IN_4_14
+GskPath *               gsk_path_measure_get_path               (GskPathMeasure         *self) G_GNUC_PURE;
+GDK_AVAILABLE_IN_4_14
+float                   gsk_path_measure_get_tolerance          (GskPathMeasure         *self) G_GNUC_PURE;
+
+GDK_AVAILABLE_IN_4_14
+float                   gsk_path_measure_get_length             (GskPathMeasure         *self);
+
+GDK_AVAILABLE_IN_4_14
+gboolean                gsk_path_measure_get_point              (GskPathMeasure         *self,
+                                                                 float                   distance,
+                                                                 GskPathPoint           *result);
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(GskPathMeasure, gsk_path_measure_unref)
+
+G_END_DECLS

gsk/gskpathopprivate.h

@@ -0,0 +1,193 @@
+/*
+ * Copyright © 2020 Benjamin Otte
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+
+#pragma once
+
+#include "gskpath.h"
+#include "gskpathbuilder.h"
+
+G_BEGIN_DECLS
+
+typedef gpointer gskpathop;
+
+static inline
+gskpathop               gsk_pathop_encode                       (GskPathOperation        op,
+                                                                 const graphene_point_t *pts);
+static inline
+const graphene_point_t *gsk_pathop_points                       (gskpathop               pop);
+static inline
+GskPathOperation        gsk_pathop_op                           (gskpathop               pop);
+
+static inline
+gboolean                gsk_pathop_foreach                      (gskpathop               pop,
+                                                                 GskPathForeachFunc      func,
+                                                                 gpointer                user_data);
+
+/* included inline so tests can use them */
+static inline
+void                    gsk_path_builder_pathop_to              (GskPathBuilder         *builder,
+                                                                 gskpathop               op);
+static inline
+void                    gsk_path_builder_pathop_reverse_to      (GskPathBuilder         *builder,
+                                                                 gskpathop               op);
+
+/* IMPLEMENTATION */
+
+/* Note:
+ *
+ * The weight of conics is encoded as p[2].x, and the endpoint is p[3].
+ * This is important, since contours store the points of adjacent
+ * operations overlapping, so we can't put the weight at the end.
+ */
+
+#define GSK_PATHOP_OPERATION_MASK (0x7)
+
+static inline gskpathop
+gsk_pathop_encode (GskPathOperation        op,
+                   const graphene_point_t *pts)
+{
+  /* g_assert (op & GSK_PATHOP_OPERATION_MASK == op); */
+  g_assert ((GPOINTER_TO_SIZE (pts) & GSK_PATHOP_OPERATION_MASK) == 0);
+
+  return GSIZE_TO_POINTER (GPOINTER_TO_SIZE (pts) | op);
+}
+
+static inline const graphene_point_t *
+gsk_pathop_points (gskpathop pop)
+{
+  return GSIZE_TO_POINTER (GPOINTER_TO_SIZE (pop) & ~GSK_PATHOP_OPERATION_MASK);
+}
+
+static inline
+GskPathOperation gsk_pathop_op (gskpathop pop)
+{
+  return GPOINTER_TO_SIZE (pop) & GSK_PATHOP_OPERATION_MASK;
+}
+
+static inline gboolean
+gsk_pathop_foreach (gskpathop          pop,
+                    GskPathForeachFunc func,
+                    gpointer           user_data)
+{
+  switch (gsk_pathop_op (pop))
+  {
+    case GSK_PATH_MOVE:
+      return func (gsk_pathop_op (pop), gsk_pathop_points (pop), 1, 0, user_data);
+
+    case GSK_PATH_CLOSE:
+    case GSK_PATH_LINE:
+      return func (gsk_pathop_op (pop), gsk_pathop_points (pop), 2, 0, user_data);
+
+    case GSK_PATH_QUAD:
+      return func (gsk_pathop_op (pop), gsk_pathop_points (pop), 3, 0, user_data);
+
+    case GSK_PATH_CUBIC:
+      return func (gsk_pathop_op (pop), gsk_pathop_points (pop), 4, 0, user_data);
+
+    case GSK_PATH_CONIC:
+      {
+        const graphene_point_t *pts = gsk_pathop_points (pop);
+        return func (gsk_pathop_op (pop), (graphene_point_t[3]) { pts[0], pts[1], pts[3] }, 3, pts[2].x, user_data);
+      }
+
+    default:
+      g_assert_not_reached ();
+      return TRUE;
+    }
+}
+
+static inline void
+gsk_path_builder_pathop_to (GskPathBuilder *builder,
+                            gskpathop       op)
+{
+  const graphene_point_t *pts = gsk_pathop_points (op);
+
+  switch (gsk_pathop_op (op))
+  {
+    case GSK_PATH_MOVE:
+      gsk_path_builder_move_to (builder, pts[0].x, pts[0].y);
+      break;
+
+    case GSK_PATH_CLOSE:
+      gsk_path_builder_close (builder);
+      break;
+
+    case GSK_PATH_LINE:
+      gsk_path_builder_line_to (builder, pts[1].x, pts[1].y);
+      break;
+
+    case GSK_PATH_QUAD:
+      gsk_path_builder_quad_to (builder, pts[1].x, pts[1].y, pts[2].x, pts[2].y);
+      break;
+
+    case GSK_PATH_CUBIC:
+      gsk_path_builder_cubic_to (builder, pts[1].x, pts[1].y, pts[2].x, pts[2].y, pts[3].x, pts[3].y);
+      break;
+
+    case GSK_PATH_CONIC:
+      gsk_path_builder_conic_to (builder, pts[1].x, pts[1].y, pts[3].x, pts[3].y, pts[2].x);
+      break;
+
+    default:
+      g_assert_not_reached ();
+      break;
+  }
+}
+
+static inline void
+gsk_path_builder_pathop_reverse_to (GskPathBuilder *builder,
+                                    gskpathop       op)
+{
+  const graphene_point_t *pts = gsk_pathop_points (op);
+
+  switch (gsk_pathop_op (op))
+  {
+    case GSK_PATH_MOVE:
+      gsk_path_builder_move_to (builder, pts[0].x, pts[0].y);
+      break;
+
+    case GSK_PATH_CLOSE:
+      gsk_path_builder_line_to (builder, pts[0].x, pts[0].y);
+      break;
+
+    case GSK_PATH_LINE:
+      gsk_path_builder_line_to (builder, pts[1].x, pts[1].y);
+      break;
+
+    case GSK_PATH_QUAD:
+      gsk_path_builder_quad_to (builder, pts[1].x, pts[1].y, pts[0].x, pts[0].y);
+      break;
+
+    case GSK_PATH_CUBIC:
+      gsk_path_builder_cubic_to (builder, pts[2].x, pts[2].y, pts[1].x, pts[1].y, pts[0].x, pts[0].y);
+      break;
+
+    case GSK_PATH_CONIC:
+      gsk_path_builder_conic_to (builder, pts[1].x, pts[1].y, pts[0].x, pts[0].y, pts[2].x);
+      break;
+
+    default:
+      g_assert_not_reached ();
+      break;
+  }
+}
+
+
+G_END_DECLS

gsk/gskpathpoint.c

@@ -0,0 +1,284 @@
+/*
+ * Copyright © 2023 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen <mclasen@redhat.com>
+ */
+
+#include "config.h"
+
+#include <math.h>
+
+#include "gskpathpointprivate.h"
+#include "gskcontourprivate.h"
+#include "gdk/gdkprivate.h"
+
+#define RAD_TO_DEG(x)          ((x) / (G_PI / 180.f))
+
+/**
+ * GskPathPoint:
+ *
+ * `GskPathPoint` is an opaque type representing a point on a path.
+ *
+ * It can be queried for properties of the path at that point, such as
+ * its tangent or its curvature.
+ *
+ * To obtain a `GskPathPoint`, use [method@Gsk.Path.get_closest_point],
+ * [method@Gsk.Path.get_start_point], [method@Gsk.Path.get_end_point]
+ * or [method@Gsk.PathMeasure.get_point].
+ *
+ * Note that `GskPathPoint` structs are meant to be stack-allocated,
+ * and don't hold a reference to the path object they are obtained from.
+ * It is the callers responsibility to keep a reference to the path
+ * as long as the `GskPathPoint` is used.
+ *
+ * Since: 4.14
+ */
+
+G_DEFINE_BOXED_TYPE (GskPathPoint, gsk_path_point,
+                     gsk_path_point_copy,
+                     gsk_path_point_free)
+
+GskPathPoint *
+gsk_path_point_copy (GskPathPoint *point)
+{
+  GskPathPoint *copy;
+
+  copy = g_new0 (GskPathPoint, 1);
+
+  memcpy (copy, point, sizeof (GskPathPoint));
+
+  return copy;
+}
+
+void
+gsk_path_point_free (GskPathPoint *point)
+{
+  g_free (point);
+}
+
+/**
+ * gsk_path_point_equal:
+ * @point1: a `GskPathPoint`
+ * @point2: another `GskPathPoint`
+ *
+ * Returns whether the two path points refer to the same
+ * location on all paths.
+ *
+ * Note that the start- and endpoint of a closed contour
+ * will compare nonequal according to this definition.
+ * Use [method@Gsk.Path.is_closed] to find out if the
+ * start- and endpoint of a concrete path refer to the
+ * same location.
+ *
+ * Return: `TRUE` if @point1 and @point2 are equal
+ *
+ * Since: 4.14
+ */
+gboolean
+gsk_path_point_equal (const GskPathPoint *point1,
+                      const GskPathPoint *point2)
+{
+  if (point1->contour == point2->contour)
+    {
+      if ((point1->idx     == point2->idx     && point1->t == point2->t) ||
+          (point1->idx + 1 == point2->idx     && point1->t == 1 && point2->t == 0) ||
+          (point1->idx     == point2->idx + 1 && point1->t == 0 && point2->t == 1))
+        return TRUE;
+    }
+
+  return FALSE;
+}
+
+/**
+ * gsk_path_point_compare:
+ * @point1: a `GskPathPoint`
+ * @point2: another `GskPathPoint`
+ *
+ * Returns whether @point1 is before or after @point2.
+ *
+ * Returns: -1 if @point1 is before @point2,
+ *   1 if @point1 is after @point2,
+ *   0 if they are equal
+ *
+ * Since: 4.14
+ */
+int
+gsk_path_point_compare (const GskPathPoint *point1,
+                        const GskPathPoint *point2)
+{
+  if (gsk_path_point_equal (point1, point2))
+    return 0;
+
+  if (point1->contour < point2->contour)
+    return -1;
+  else if (point1->contour > point2->contour)
+    return 1;
+  else if (point1->idx < point2->idx)
+    return -1;
+  else if (point1->idx > point2->idx)
+    return 1;
+  else if (point1->t < point2->t)
+    return -1;
+  else if (point1->t > point2->t)
+    return 1;
+
+  return 0;
+}
+
+/**
+ * gsk_path_point_get_position:
+ * @point: a `GskPathPoint`
+ * @path: the path that @point is on
+ * @position: (out caller-allocates): Return location for
+ *   the coordinates of the point
+ *
+ * Gets the position of the point.
+ *
+ * Since: 4.14
+ */
+void
+gsk_path_point_get_position (const GskPathPoint *point,
+                             GskPath            *path,
+                             graphene_point_t   *position)
+{
+  const GskContour *contour;
+
+  g_return_if_fail (path != NULL);
+  g_return_if_fail (gsk_path_point_valid (point, path));
+  g_return_if_fail (position != NULL);
+
+  contour = gsk_path_get_contour (path, point->contour),
+  gsk_contour_get_position (contour, point, position);
+}
+
+/**
+ * gsk_path_point_get_tangent:
+ * @point: a `GskPathPoint`
+ * @path: the path that @point is on
+ * @direction: the direction for which to return the tangent
+ * @tangent: (out caller-allocates): Return location for
+ *   the tangent at the point
+ *
+ * Gets the tangent of the path at the point.
+ *
+ * Note that certain points on a path may not have a single
+ * tangent, such as sharp turns. At such points, there are
+ * two tangents -- the direction of the path going into the
+ * point, and the direction coming out of it. The @direction
+ * argument lets you choose which one to get.
+ *
+ * If you want to orient something in the direction of the
+ * path, [method@Gsk.PathPoint.get_rotation] may be more
+ * convenient to use.
+ *
+ * Since: 4.14
+ */
+void
+gsk_path_point_get_tangent (const GskPathPoint *point,
+                            GskPath            *path,
+                            GskPathDirection    direction,
+                            graphene_vec2_t    *tangent)
+{
+  const GskContour *contour;
+
+  g_return_if_fail (path != NULL);
+  g_return_if_fail (gsk_path_point_valid (point, path));
+  g_return_if_fail (tangent != NULL);
+
+  contour = gsk_path_get_contour (path, point->contour),
+  gsk_contour_get_tangent (contour, point, direction, tangent);
+}
+
+/**
+ * gsk_path_point_get_rotation:
+ * @point: a `GskPathPoint`
+ * @path: the path that @point is on
+ * @direction: the direction for which to return the rotation
+ *
+ * Gets the direction of the tangent at a given point.
+ *
+ * This is a convenience variant of [method@Gsk.PathPoint.get_tangent]
+ * that returns the angle between the tangent and the X axis. The angle
+ * can e.g. be used in
+ * [gtk_snapshot_rotate()](../gtk4/method.Snapshot.rotate.html).
+ *
+ * Returns: the angle between the tangent and the X axis, in degrees
+ *
+ * Since: 4.14
+ */
+float
+gsk_path_point_get_rotation (const GskPathPoint *point,
+                             GskPath            *path,
+                             GskPathDirection    direction)
+{
+  graphene_vec2_t tangent;
+
+  g_return_val_if_fail (path != NULL, 0);
+  g_return_val_if_fail (gsk_path_point_valid (point, path), 0);
+
+  gsk_path_point_get_tangent (point, path, direction, &tangent);
+
+  return RAD_TO_DEG (atan2f (graphene_vec2_get_y (&tangent),
+                             graphene_vec2_get_x (&tangent)));
+}
+
+/**
+ * gsk_path_point_get_curvature:
+ * @point: a `GskPathPoint`
+ * @path: the path that @point is on
+ * @direction: the direction for which to return the curvature
+ * @center: (out caller-allocates) (nullable): Return location for
+ *   the center of the osculating circle
+ *
+ * Calculates the curvature of the path at the point.
+ *
+ * Optionally, returns the center of the osculating circle as well.
+ * The curvature is the inverse of the radius of the osculating circle.
+ *
+ * Lines have a curvature of zero (indicating an osculating circle of
+ * infinite radius. In this case, the @center is not modified.
+ *
+ * Circles with a radius of zero have `INFINITY` as curvature
+ *
+ * Note that certain points on a path may not have a single curvature,
+ * such as sharp turns. At such points, there are two curvatures --
+ * the (limit of) the curvature of the path going into the point,
+ * and the (limit of) the curvature of the path coming out of it.
+ * The @direction argument lets you choose which one to get.
+ *
+ * <picture>
+ *   <source srcset="curvature-dark.png" media="(prefers-color-scheme: dark)">
+ *   <img alt="Osculating circle" src="curvature-light.png">
+ * </picture>
+
+ * Returns: The curvature of the path at the given point
+ *
+ * Since: 4.14
+ */
+float
+gsk_path_point_get_curvature (const GskPathPoint *point,
+                              GskPath            *path,
+                              GskPathDirection    direction,
+                              graphene_point_t   *center)
+{
+  const GskContour *contour;
+
+  g_return_val_if_fail (path != NULL, 0);
+  g_return_val_if_fail (gsk_path_point_valid (point, path), 0);
+
+  contour = gsk_path_get_contour (path, point->contour);
+  return gsk_contour_get_curvature (contour, point, direction, center);
+}

gsk/gskpathpoint.h

@@ -0,0 +1,90 @@
+/*
+ * Copyright © 2023 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen <mclasen@redhat.com>
+ */
+
+#pragma once
+
+#if !defined (__GSK_H_INSIDE__) && !defined (GTK_COMPILATION)
+#error "Only <gsk/gsk.h> can be included directly."
+#endif
+
+
+#include <gsk/gsktypes.h>
+
+G_BEGIN_DECLS
+
+#define GSK_TYPE_PATH_POINT (gsk_path_point_get_type ())
+
+typedef struct _GskPathPoint GskPathPoint;
+struct _GskPathPoint {
+  /*< private >*/
+  union {
+    struct {
+      gsize contour;
+      gsize idx;
+      float t;
+    };
+    gpointer padding[8];
+    graphene_vec4_t alignment;
+  };
+};
+
+GDK_AVAILABLE_IN_4_14
+GType                   gsk_path_point_get_type        (void) G_GNUC_CONST;
+
+GDK_AVAILABLE_IN_4_14
+GskPathPoint *          gsk_path_point_copy            (GskPathPoint       *point);
+
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_point_free            (GskPathPoint       *point);
+
+GDK_AVAILABLE_IN_4_14
+gboolean                gsk_path_point_equal           (const GskPathPoint *point1,
+                                                        const GskPathPoint *point2);
+
+GDK_AVAILABLE_IN_4_14
+int                     gsk_path_point_compare         (const GskPathPoint *point1,
+                                                        const GskPathPoint *point2);
+
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_point_get_position    (const GskPathPoint *point,
+                                                        GskPath            *path,
+                                                        graphene_point_t   *position);
+
+GDK_AVAILABLE_IN_4_14
+void                    gsk_path_point_get_tangent     (const GskPathPoint *point,
+                                                        GskPath            *path,
+                                                        GskPathDirection    direction,
+                                                        graphene_vec2_t    *tangent);
+
+GDK_AVAILABLE_IN_4_14
+float                   gsk_path_point_get_rotation    (const GskPathPoint *point,
+                                                        GskPath            *path,
+                                                        GskPathDirection    direction);
+
+GDK_AVAILABLE_IN_4_14
+float                   gsk_path_point_get_curvature   (const GskPathPoint *point,
+                                                        GskPath            *path,
+                                                        GskPathDirection    direction,
+                                                        graphene_point_t   *center);
+
+GDK_AVAILABLE_IN_4_14
+float                   gsk_path_point_get_distance    (const GskPathPoint *point,
+                                                        GskPathMeasure     *measure);
+
+G_END_DECLS

gsk/gskpathpointprivate.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include "gskpathpoint.h"
+#include "gskcontourprivate.h"
+
+G_BEGIN_DECLS
+
+#define GSK_PATH_POINT_INIT(c,i,tt) ((GskPathPoint){ .contour=(c), .idx=(i), .t=(tt) })
+
+static inline gboolean
+gsk_path_point_valid (const GskPathPoint *point,
+                      GskPath            *path)
+{
+  const GskContour *contour;
+  gsize n_ops;
+
+  if (point == NULL)
+    return FALSE;
+
+  if (path == NULL)
+    return TRUE;
+
+  if (point->contour >= gsk_path_get_n_contours (path))
+    return FALSE;
+
+  contour = gsk_path_get_contour (path, point->contour);
+  n_ops = gsk_contour_get_n_ops (contour);
+  if ((n_ops > 1 && point->idx >= n_ops) ||
+      (n_ops == 1 && point->idx > n_ops))
+    return FALSE;
+
+  if (point->t < 0 || point->t > 1)
+    return FALSE;
+
+  return TRUE;
+}
+
+G_END_DECLS
+

gsk/gskpathprivate.h

@@ -0,0 +1,60 @@
+/*
+ * Copyright © 2020 Benjamin Otte
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+
+#pragma once
+
+#include "gskpath.h"
+
+#include "gskpathopprivate.h"
+
+G_BEGIN_DECLS
+
+typedef enum
+{
+  GSK_PATH_FLAT,
+  GSK_PATH_CLOSED
+} GskPathFlags;
+
+typedef struct _GskContour GskContour;
+typedef struct _GskRealPathPoint GskRealPathPoint;
+
+/* Same as Skia, so looks like a good value. ¯\_(ツ)_/¯ */
+#define GSK_PATH_TOLERANCE_DEFAULT (0.5)
+
+GskPath *               gsk_path_new_from_contours              (const GSList           *contours);
+
+gsize                   gsk_path_get_n_contours                 (const GskPath          *self);
+const GskContour *      gsk_path_get_contour                    (const GskPath          *self,
+                                                                 gsize                   i);
+
+GskPathFlags            gsk_path_get_flags                      (const GskPath          *self);
+
+gboolean                gsk_path_foreach_with_tolerance         (GskPath                *self,
+                                                                 GskPathForeachFlags     flags,
+                                                                 double                  tolerance,
+                                                                 GskPathForeachFunc      func,
+                                                                 gpointer                user_data);
+
+
+void                    gsk_path_builder_add_contour            (GskPathBuilder         *builder,
+                                                                 GskContour             *contour);
+
+G_END_DECLS
+

gsk/gskpointprivate.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <graphene.h>
+
+static inline void G_GNUC_PURE
+gsk_point_interpolate (const graphene_point_t *p1,
+                       const graphene_point_t *p2,
+                       float t,
+                       graphene_point_t *p)
+{
+  p->x = p1->x * (1 - t) + p2->x * t;
+  p->Y = p1->y * (1 - t) + p2->y * t;
+}
+
+static inline float G_GNUC_PURE
+gsk_point_distance (const graphene_point_t *p1,
+                    const graphene_point_t *p2)
+{
+  return sqrtf ((p1->x - p2->x)*(p1->x - p2->x) + (p1->y - p2->y)*(p1->y - p2->y));
+}