gl renderer: Add simple blend node implementation

Apparently genTextures and friends only "reserves names", initializing
them will actually create them. Using glObjectLabel on textures before
initializing them will throw a GL_INVALID_VALUE error.

.gitlab-ci/test-docker.sh

@@ -32,7 +32,6 @@ xvfb-run -a -s "-screen 0 1024x768x24" \
         --timeout-multiplier 2 \
         --print-errorlogs \
         --suite=gtk \
-        --no-suite=gtk:gsk \
         --no-suite=gtk:a11y
 
 # Save the exit code

demos/meson.build

@@ -1,3 +1,4 @@
 subdir('gtk-demo')
 subdir('icon-browser')
+subdir('node-editor')
 subdir('widget-factory')

demos/node-editor/main.c

@@ -0,0 +1,28 @@
+/*
+ * Copyright © 2019 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 <node-editor-application.h>
+
+int
+main (int argc, char *argv[])
+{
+  return g_application_run (G_APPLICATION (node_editor_application_new ()), argc, argv);
+}

demos/node-editor/meson.build

@@ -0,0 +1,17 @@
+node_editor_sources = [
+  'main.c',
+  'node-editor-application.c',
+  'node-editor-window.c',
+]
+
+node_editor_resources = gnome.compile_resources('node_editor_resources',
+                                                'node-editor.gresource.xml',
+                                                source_dir: '.')
+
+executable('gtk4-node-editor',
+           node_editor_sources, node_editor_resources,
+           dependencies: libgtk_dep,
+           include_directories: confinc,
+           gui_app: true,
+           link_args: extra_demo_ldflags,
+           install: false)

demos/node-editor/node-editor-application.c

@@ -0,0 +1,114 @@
+/*
+ * Copyright © 2019 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 "node-editor-application.h"
+
+#include "node-editor-window.h"
+
+struct _NodeEditorApplication
+{
+  GtkApplication parent;
+};
+
+struct _NodeEditorApplicationClass
+{
+  GtkApplicationClass parent_class;
+};
+
+G_DEFINE_TYPE(NodeEditorApplication, node_editor_application, GTK_TYPE_APPLICATION);
+
+static void
+node_editor_application_init (NodeEditorApplication *app)
+{
+}
+
+static void
+quit_activated (GSimpleAction *action,
+                GVariant      *parameter,
+                gpointer       data)
+{
+  g_application_quit (G_APPLICATION (data));
+}
+
+static GActionEntry app_entries[] =
+{
+  { "quit", quit_activated, NULL, NULL, NULL }
+};
+
+static void
+node_editor_application_startup (GApplication *app)
+{
+  const gchar *quit_accels[2] = { "<Ctrl>Q", NULL };
+
+  G_APPLICATION_CLASS (node_editor_application_parent_class)->startup (app);
+
+  g_action_map_add_action_entries (G_ACTION_MAP (app),
+                                   app_entries, G_N_ELEMENTS (app_entries),
+                                   app);
+  gtk_application_set_accels_for_action (GTK_APPLICATION (app),
+                                         "app.quit",
+                                         quit_accels);
+}
+
+static void
+node_editor_application_activate (GApplication *app)
+{
+  NodeEditorWindow *win;
+
+  win = node_editor_window_new (NODE_EDITOR_APPLICATION (app));
+  gtk_window_present (GTK_WINDOW (win));
+}
+
+static void
+node_editor_application_open (GApplication  *app,
+                              GFile        **files,
+                              gint           n_files,
+                              const gchar   *hint)
+{
+  NodeEditorWindow *win;
+  gint i;
+
+  for (i = 0; i < n_files; i++)
+    {
+      win = node_editor_window_new (NODE_EDITOR_APPLICATION (app));
+      node_editor_window_load (win, files[i]);
+      gtk_window_present (GTK_WINDOW (win));
+    }
+}
+
+static void
+node_editor_application_class_init (NodeEditorApplicationClass *class)
+{
+  GApplicationClass *application_class = G_APPLICATION_CLASS (class);
+
+  application_class->startup = node_editor_application_startup;
+  application_class->activate = node_editor_application_activate;
+  application_class->open = node_editor_application_open;
+}
+
+NodeEditorApplication *
+node_editor_application_new (void)
+{
+  return g_object_new (NODE_EDITOR_APPLICATION_TYPE,
+                       "application-id", "org.gtk.gtk4.NodeEditor",
+                       "flags", G_APPLICATION_HANDLES_OPEN,
+                       NULL);
+}

demos/node-editor/node-editor-application.h

@@ -0,0 +1,38 @@
+/*
+ * Copyright © 2019 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>
+ */
+
+#ifndef __NODE_EDITOR_APPLICATION_H__
+#define __NODE_EDITOR_APPLICATION_H__
+
+#include <gtk/gtk.h>
+
+
+#define NODE_EDITOR_APPLICATION_TYPE (node_editor_application_get_type ())
+#define NODE_EDITOR_APPLICATION(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), NODE_EDITOR_APPLICATION_TYPE, NodeEditorApplication))
+
+
+typedef struct _NodeEditorApplication       NodeEditorApplication;
+typedef struct _NodeEditorApplicationClass  NodeEditorApplicationClass;
+
+
+GType           node_editor_application_get_type    (void);
+NodeEditorApplication *node_editor_application_new         (void);
+
+
+#endif /* __NODE_EDITOR_APPLICATION_H__ */

demos/node-editor/node-editor-window.c

@@ -0,0 +1,431 @@
+/*
+ * Copyright © 2019 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 "node-editor-window.h"
+
+#include "gsk/gskrendernodeparserprivate.h"
+
+typedef struct
+{
+  gsize  start_chars;
+  gsize  end_chars;
+  char  *message;
+} TextViewError;
+
+struct _NodeEditorWindow
+{
+  GtkApplicationWindow parent;
+
+  GtkWidget *picture;
+  GtkWidget *text_view;
+  GtkTextBuffer *text_buffer;
+
+  GArray *errors;
+};
+
+struct _NodeEditorWindowClass
+{
+  GtkApplicationWindowClass parent_class;
+};
+
+G_DEFINE_TYPE(NodeEditorWindow, node_editor_window, GTK_TYPE_APPLICATION_WINDOW);
+
+static void
+text_view_error_free (TextViewError *e)
+{
+  g_free (e->message);
+}
+
+static gchar *
+get_current_text (GtkTextBuffer *buffer)
+{
+  GtkTextIter start, end;
+
+  gtk_text_buffer_get_start_iter (buffer, &start);
+  gtk_text_buffer_get_end_iter (buffer, &end);
+  gtk_text_buffer_remove_all_tags (buffer, &start, &end);
+
+  return gtk_text_buffer_get_text (buffer, &start, &end, FALSE);
+}
+
+static void
+deserialize_error_func (const GtkCssSection *section,
+                        const GError        *error,
+                        gpointer             user_data)
+{
+  const GtkCssLocation *start_location = gtk_css_section_get_start_location (section);
+  const GtkCssLocation *end_location = gtk_css_section_get_end_location (section);
+  NodeEditorWindow *self = user_data;
+  GtkTextIter start_iter, end_iter;
+  TextViewError text_view_error;
+
+  gtk_text_buffer_get_iter_at_line_offset (self->text_buffer, &start_iter,
+                                           start_location->lines,
+                                           start_location->line_chars);
+  gtk_text_buffer_get_iter_at_line_offset (self->text_buffer, &end_iter,
+                                           end_location->lines,
+                                           end_location->line_chars);
+
+  gtk_text_buffer_apply_tag_by_name (self->text_buffer, "error",
+                                     &start_iter, &end_iter);
+
+  text_view_error.start_chars = start_location->chars;
+  text_view_error.end_chars = end_location->chars;
+  text_view_error.message = g_strdup (error->message);
+  g_array_append_val (self->errors, text_view_error);
+}
+
+static void
+text_changed (GtkTextBuffer    *buffer,
+              NodeEditorWindow *self)
+{
+  GskRenderNode *node;
+  char *text;
+  GBytes *bytes;
+
+  g_array_remove_range (self->errors, 0, self->errors->len);
+  text = get_current_text (self->text_buffer);
+  bytes = g_bytes_new_take (text, strlen (text));
+
+  /* If this is too slow, go fix the parser performance */
+  node = gsk_render_node_deserialize (bytes, deserialize_error_func, self);
+  g_bytes_unref (bytes);
+  if (node)
+    {
+      /* XXX: Is this code necessary or can we have API to turn nodes into paintables? */
+      GtkSnapshot *snapshot;
+      GdkPaintable *paintable;
+      graphene_rect_t bounds;
+
+      snapshot = gtk_snapshot_new ();
+      gsk_render_node_get_bounds (node, &bounds);
+      gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (- bounds.origin.x, - bounds.origin.y));
+      gtk_snapshot_append_node (snapshot, node);
+      gsk_render_node_unref (node);
+      paintable = gtk_snapshot_free_to_paintable (snapshot, &bounds.size);
+      gtk_picture_set_paintable (GTK_PICTURE (self->picture), paintable);
+      g_clear_object (&paintable);
+    }
+  else
+    {
+      gtk_picture_set_paintable (GTK_PICTURE (self->picture), NULL);
+    }
+}
+
+static gboolean
+text_view_query_tooltip_cb (GtkWidget        *widget,
+                            int               x,
+                            int               y,
+                            gboolean          keyboard_tip,
+                            GtkTooltip       *tooltip,
+                            NodeEditorWindow *self)
+{
+  GtkTextIter iter;
+  guint i;
+
+  if (keyboard_tip)
+    {
+      gint offset;
+
+      g_object_get (self->text_buffer, "cursor-position", &offset, NULL);
+      gtk_text_buffer_get_iter_at_offset (self->text_buffer, &iter, offset);
+    }
+  else
+    {
+      gint bx, by, trailing;
+
+      gtk_text_view_window_to_buffer_coords (GTK_TEXT_VIEW (self->text_view), GTK_TEXT_WINDOW_TEXT,
+                                             x, y, &bx, &by);
+      gtk_text_view_get_iter_at_position (GTK_TEXT_VIEW (self->text_view), &iter, &trailing, bx, by);
+    }
+
+  for (i = 0; i < self->errors->len; i ++)
+    {
+      const TextViewError *e = &g_array_index (self->errors, TextViewError, i);
+      GtkTextIter start_iter, end_iter;
+
+      gtk_text_buffer_get_iter_at_offset (self->text_buffer, &start_iter, e->start_chars);
+      gtk_text_buffer_get_iter_at_offset (self->text_buffer, &end_iter, e->end_chars);
+
+      if (gtk_text_iter_in_range (&iter, &start_iter, &end_iter))
+        {
+          gtk_tooltip_set_text (tooltip, e->message);
+          return TRUE;
+        }
+    }
+
+  return FALSE;
+}
+
+gboolean
+node_editor_window_load (NodeEditorWindow *self,
+                         GFile            *file)
+{
+  GtkTextIter end;
+  GBytes *bytes;
+
+  bytes = g_file_load_bytes (file, NULL, NULL, NULL);
+  if (bytes == NULL)
+    return FALSE;
+
+  if (!g_utf8_validate (g_bytes_get_data (bytes, NULL), g_bytes_get_size (bytes), NULL))
+    {
+      g_bytes_unref (bytes);
+      return FALSE;
+    }
+
+  gtk_text_buffer_get_end_iter (self->text_buffer, &end);
+  gtk_text_buffer_insert (self->text_buffer,
+                          &end,
+                          g_bytes_get_data (bytes, NULL),
+                          g_bytes_get_size (bytes));
+
+  return TRUE;
+}
+
+static void
+open_response_cb (GtkWidget        *dialog,
+                  gint              response,
+                  NodeEditorWindow *self)
+{
+  gtk_widget_hide (dialog);
+
+  if (response == GTK_RESPONSE_ACCEPT)
+    {
+      GFile *file;
+
+      file = gtk_file_chooser_get_file (GTK_FILE_CHOOSER (dialog));
+      node_editor_window_load (self, file);
+      g_object_unref (file);
+    }
+
+  gtk_widget_destroy (dialog);
+}
+
+static void
+open_cb (GtkWidget        *button,
+         NodeEditorWindow *self)
+{
+  GtkWidget *dialog;
+
+  dialog = gtk_file_chooser_dialog_new ("Open node file",
+                                        GTK_WINDOW (gtk_widget_get_toplevel (GTK_WIDGET (button))),
+                                        GTK_FILE_CHOOSER_ACTION_OPEN,
+                                        "_Cancel", GTK_RESPONSE_CANCEL,
+                                        "_Load", GTK_RESPONSE_ACCEPT,
+                                        NULL);
+
+  gtk_dialog_set_default_response (GTK_DIALOG (dialog), GTK_RESPONSE_ACCEPT);
+  gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
+  gtk_file_chooser_set_current_folder (GTK_FILE_CHOOSER (dialog), ".");
+  g_signal_connect (dialog, "response", G_CALLBACK (open_response_cb), self);
+  gtk_widget_show (dialog);
+}
+
+static void
+save_response_cb (GtkWidget        *dialog,
+                  gint              response,
+                  NodeEditorWindow *self)
+{
+  gtk_widget_hide (dialog);
+
+  if (response == GTK_RESPONSE_ACCEPT)
+    {
+      char *text, *filename;
+      GError *error = NULL;
+
+      text = get_current_text (self->text_buffer);
+
+      filename = gtk_file_chooser_get_filename (GTK_FILE_CHOOSER (dialog));
+      if (!g_file_set_contents (filename, text, -1, &error))
+        {
+          GtkWidget *dialog;
+
+          dialog = gtk_message_dialog_new (GTK_WINDOW (gtk_widget_get_toplevel (GTK_WIDGET (self))),
+                                           GTK_DIALOG_MODAL|GTK_DIALOG_DESTROY_WITH_PARENT,
+                                           GTK_MESSAGE_INFO,
+                                           GTK_BUTTONS_OK,
+                                           "Saving failed");
+          gtk_message_dialog_format_secondary_text (GTK_MESSAGE_DIALOG (dialog),
+                                                    "%s", error->message);
+          g_signal_connect (dialog, "response", G_CALLBACK (gtk_widget_destroy), NULL);
+          gtk_widget_show (dialog);
+          g_error_free (error);
+        }
+      g_free (filename);
+    }
+
+  gtk_widget_destroy (dialog);
+}
+
+static void
+save_cb (GtkWidget        *button,
+         NodeEditorWindow *self)
+{
+  GtkWidget *dialog;
+
+  dialog = gtk_file_chooser_dialog_new ("Save node",
+                                        GTK_WINDOW (gtk_widget_get_toplevel (GTK_WIDGET (button))),
+                                        GTK_FILE_CHOOSER_ACTION_SAVE,
+                                        "_Cancel", GTK_RESPONSE_CANCEL,
+                                        "_Save", GTK_RESPONSE_ACCEPT,
+                                        NULL);
+
+  gtk_dialog_set_default_response (GTK_DIALOG (dialog), GTK_RESPONSE_ACCEPT);
+  gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
+  gtk_file_chooser_set_do_overwrite_confirmation (GTK_FILE_CHOOSER (dialog), TRUE);
+  gtk_file_chooser_set_current_folder (GTK_FILE_CHOOSER (dialog), ".");
+  g_signal_connect (dialog, "response", G_CALLBACK (save_response_cb), self);
+  gtk_widget_show (dialog);
+}
+
+static GdkTexture *
+create_texture (NodeEditorWindow *self)
+{
+  GdkPaintable *paintable;
+  GtkSnapshot *snapshot;
+  GskRenderer *renderer;
+  GskRenderNode *node;
+  GdkTexture *texture;
+
+  paintable = gtk_picture_get_paintable (GTK_PICTURE (self->picture));
+  if (paintable == NULL ||
+      gdk_paintable_get_intrinsic_width (paintable) <= 0 ||
+      gdk_paintable_get_intrinsic_height (paintable) <= 0)
+    return NULL;
+  snapshot = gtk_snapshot_new ();
+  gdk_paintable_snapshot (paintable, snapshot, gdk_paintable_get_intrinsic_width (paintable), gdk_paintable_get_intrinsic_height (paintable));
+  node = gtk_snapshot_free_to_node (snapshot);
+  if (node == NULL)
+    return NULL;
+
+  /* ahem */
+  renderer = GTK_ROOT_GET_IFACE (gtk_widget_get_root (GTK_WIDGET (self)))->get_renderer (gtk_widget_get_root (GTK_WIDGET (self)));
+  texture = gsk_renderer_render_texture (renderer, node, NULL);
+  gsk_render_node_unref (node);
+
+  return texture;
+}
+
+static void
+export_image_response_cb (GtkWidget  *dialog,
+                          gint        response,
+                          GdkTexture *texture)
+{
+  gtk_widget_hide (dialog);
+
+  if (response == GTK_RESPONSE_ACCEPT)
+    {
+      char *filename;
+
+      filename = gtk_file_chooser_get_filename (GTK_FILE_CHOOSER (dialog));
+      if (!gdk_texture_save_to_png (texture, filename))
+        {
+          GtkWidget *message_dialog;
+
+          message_dialog = gtk_message_dialog_new (GTK_WINDOW (gtk_window_get_transient_for (GTK_WINDOW (dialog))),
+                                                   GTK_DIALOG_MODAL|GTK_DIALOG_DESTROY_WITH_PARENT,
+                                                   GTK_MESSAGE_INFO,
+                                                   GTK_BUTTONS_OK,
+                                                   "Exporting to image failed");
+          g_signal_connect (message_dialog, "response", G_CALLBACK (gtk_widget_destroy), NULL);
+          gtk_widget_show (message_dialog);
+        }
+      g_free (filename);
+    }
+
+  gtk_widget_destroy (dialog);
+  g_object_unref (texture);
+}
+
+static void
+export_image_cb (GtkWidget        *button,
+                 NodeEditorWindow *self)
+{
+  GdkTexture *texture;
+  GtkWidget *dialog;
+
+  texture = create_texture (self);
+  if (texture == NULL)
+    return;
+
+  dialog = gtk_file_chooser_dialog_new ("",
+                                        GTK_WINDOW (gtk_widget_get_toplevel (GTK_WIDGET (button))),
+                                        GTK_FILE_CHOOSER_ACTION_SAVE,
+                                        "_Cancel", GTK_RESPONSE_CANCEL,
+                                        "_Save", GTK_RESPONSE_ACCEPT,
+                                        NULL);
+
+  gtk_dialog_set_default_response (GTK_DIALOG (dialog), GTK_RESPONSE_ACCEPT);
+  gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
+  gtk_file_chooser_set_do_overwrite_confirmation (GTK_FILE_CHOOSER (dialog), TRUE);
+  g_signal_connect (dialog, "response", G_CALLBACK (export_image_response_cb), texture);
+  gtk_widget_show (dialog);
+}
+
+static void
+node_editor_window_finalize (GObject *object)
+{
+  NodeEditorWindow *self = (NodeEditorWindow *)object;
+
+  g_array_free (self->errors, TRUE);
+
+  G_OBJECT_CLASS (node_editor_window_parent_class)->finalize (object);
+}
+
+static void
+node_editor_window_class_init (NodeEditorWindowClass *class)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
+
+  object_class->finalize = node_editor_window_finalize;
+
+  gtk_widget_class_set_template_from_resource (GTK_WIDGET_CLASS (class),
+                                               "/org/gtk/gtk4/node-editor/node-editor-window.ui");
+
+  gtk_widget_class_bind_template_child (widget_class, NodeEditorWindow, text_buffer);
+  gtk_widget_class_bind_template_child (widget_class, NodeEditorWindow, text_view);
+  gtk_widget_class_bind_template_child (widget_class, NodeEditorWindow, picture);
+
+  gtk_widget_class_bind_template_callback (widget_class, text_changed);
+  gtk_widget_class_bind_template_callback (widget_class, text_view_query_tooltip_cb);
+  gtk_widget_class_bind_template_callback (widget_class, open_cb);
+  gtk_widget_class_bind_template_callback (widget_class, save_cb);
+  gtk_widget_class_bind_template_callback (widget_class, export_image_cb);
+}
+
+static void
+node_editor_window_init (NodeEditorWindow *self)
+{
+  gtk_widget_init_template (GTK_WIDGET (self));
+
+  self->errors = g_array_new (FALSE, TRUE, sizeof (TextViewError));
+  g_array_set_clear_func (self->errors, (GDestroyNotify)text_view_error_free);
+}
+
+NodeEditorWindow *
+node_editor_window_new (NodeEditorApplication *application)
+{
+  return g_object_new (NODE_EDITOR_WINDOW_TYPE,
+                       "application", application,
+                       NULL);
+}

demos/node-editor/node-editor-window.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright © 2019 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>
+ */
+
+#ifndef __NODE_EDITOR_WINDOW_H__
+#define __NODE_EDITOR_WINDOW_H__
+
+#include <gtk/gtk.h>
+
+#include "node-editor-application.h"
+
+#define NODE_EDITOR_WINDOW_TYPE (node_editor_window_get_type ())
+#define NODE_EDITOR_WINDOW(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), NODE_EDITOR_WINDOW_TYPE, NodeEditorWindow))
+
+
+typedef struct _NodeEditorWindow         NodeEditorWindow;
+typedef struct _NodeEditorWindowClass    NodeEditorWindowClass;
+
+
+GType                   node_editor_window_get_type     (void);
+
+NodeEditorWindow *      node_editor_window_new          (NodeEditorApplication  *application);
+
+gboolean                node_editor_window_load         (NodeEditorWindow       *self,
+                                                         GFile                  *file);
+
+#endif /* __NODE_EDITOR_WINDOW_H__ */

demos/node-editor/node-editor-window.ui

@@ -0,0 +1,99 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <object class="GtkTextTagTable" id="tags">
+    <child type="tag">
+      <object class="GtkTextTag">
+        <property name="name">error</property>
+        <property name="underline">error</property>
+      </object>
+    </child>
+  </object>
+  <object class="GtkTextBuffer" id="text_buffer">
+    <property name="tag-table">tags</property>
+    <signal name="changed" handler="text_changed"/>
+  </object>
+  <template class="NodeEditorWindow" parent="GtkApplicationWindow">
+    <style>
+      <class name="devel"/>
+    </style>
+    <property name="title" translatable="yes">GTK Node Editor</property>
+    <property name="default-width">1024</property>
+    <property name="default-height">768</property>
+    <child type="titlebar">
+      <object class="GtkHeaderBar" id="header">
+        <property name="title" translatable="yes">GTK Node Editor</property>
+        <property name="show-title-buttons">1</property>
+        <child type="start">
+          <object class="GtkButton">
+            <property name="icon-name">document-open-symbolic</property>
+            <property name="tooltip-text">Open node file</property>
+            <signal name="clicked" handler="open_cb"/>
+          </object>
+        </child>
+        <child type="start">
+          <object class="GtkButton">
+            <property name="icon-name">document-save-symbolic</property>
+            <property name="tooltip-text">Save to node file</property>
+            <signal name="clicked" handler="save_cb"/>
+          </object>
+        </child>
+        <child type="start">
+          <object class="GtkButton">
+            <property name="icon-name">insert-image-symbolic</property>
+            <property name="tooltip-text">Export to image</property>
+            <signal name="clicked" handler="export_image_cb"/>
+          </object>
+        </child>
+        <child type="title">
+          <object class="GtkLabel">
+            <property name="label" translatable="yes">GTK Node Editor</property>
+          </object>
+        </child>
+      </object>
+    </child>
+    <child>
+      <object class="GtkPaned">
+        <property name="shrink-child2">false</property>
+        <property name="position">400</property>
+        <child>
+          <object class="GtkScrolledWindow">
+            <property name="hscrollbar-policy">never</property>
+            <property name="expand">1</property>
+            <child>
+              <object class="GtkTextView" id="text_view">
+                <property name="buffer">text_buffer</property>
+                <property name="wrap-mode">word</property>
+                <property name="monospace">1</property>
+                <property name="has-focus">1</property>
+                <property name="top-margin">6</property>
+                <property name="left-margin">6</property>
+                <property name="right-margin">6</property>
+                <property name="bottom-margin">6</property>
+                <property name="has-tooltip">1</property>
+                <signal name="query-tooltip" handler="text_view_query_tooltip_cb"/>
+              </object>
+            </child>
+          </object>
+        </child>
+        <child>
+          <object class="GtkScrolledWindow">
+            <property name="expand">1</property>
+            <property name="min-content-height">100</property>
+            <property name="min-content-width">100</property>
+            <child>
+              <object class="GtkViewport">
+                <child>
+                  <object class="GtkPicture" id="picture">
+                    <property name="can-shrink">0</property>
+                    <property name="halign">center</property>
+                    <property name="valign">center</property>
+                  </object>
+                </child>
+              </object>
+            </child>
+          </object>
+        </child>
+      </object>
+    </child>
+  </template>
+</interface>

demos/node-editor/node-editor.gresource.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<gresources>
+  <gresource prefix="/org/gtk/gtk4/node-editor">
+    <file preprocess="xml-stripblanks">node-editor-window.ui</file>
+  </gresource>
+</gresources>

gdk/gdkglcontext.c

@@ -116,6 +116,8 @@ typedef struct {
 
   int use_es;
 
+  int max_debug_label_length;
+
   GdkGLContextPaintData *paint_data;
 } GdkGLContextPrivate;
 
@@ -457,11 +459,14 @@ gdk_gl_context_push_debug_group_printf (GdkGLContext *context,
 
   if (priv->use_khr_debug)
     {
+      int msg_len;
+
       va_start (args, format);
       message = g_strdup_vprintf (format, args);
       va_end (args);
 
-      glPushDebugGroupKHR (GL_DEBUG_SOURCE_APPLICATION, 0, -1, message);
+      msg_len = MIN (priv->max_debug_label_length, strlen (message) - 1);
+      glPushDebugGroupKHR (GL_DEBUG_SOURCE_APPLICATION, 0, msg_len, message);
       g_free (message);
     }
 }
@@ -500,11 +505,15 @@ gdk_gl_context_label_object_printf  (GdkGLContext *context,
 
   if (priv->use_khr_debug)
     {
+      int msg_len;
+
       va_start (args, format);
       message = g_strdup_vprintf (format, args);
       va_end (args);
 
-      glObjectLabel (identifier, name, -1, message);
+      msg_len = MIN (priv->max_debug_label_length, strlen (message) - 1);
+
+      glObjectLabel (identifier, name, msg_len, message);
       g_free (message);
     }
 }
@@ -992,7 +1001,10 @@ gdk_gl_context_check_extensions (GdkGLContext *context)
   display = gdk_draw_context_get_display (GDK_DRAW_CONTEXT (context));
 
   if (priv->has_khr_debug && GDK_DISPLAY_DEBUG_CHECK (display, GL_DEBUG))
-    priv->use_khr_debug = TRUE;
+    {
+      priv->use_khr_debug = TRUE;
+      glGetIntegerv (GL_MAX_LABEL_LENGTH, &priv->max_debug_label_length);
+    }
   if (!priv->use_es && GDK_DISPLAY_DEBUG_CHECK (display, GL_TEXTURE_RECT))
     priv->use_texture_rectangle = TRUE;
   else if (has_npot)

gsk/gl/gskgldriver.c

@@ -535,8 +535,6 @@ gsk_gl_driver_get_texture_for_texture (GskGLDriver *self,
     }
 
   t = create_texture (self, gdk_texture_get_width (texture), gdk_texture_get_height (texture));
-  gdk_gl_context_label_object_printf (self->gl_context, GL_TEXTURE, t->texture_id,
-                                      "GdkTexture<%p> %d", texture, t->texture_id);
 
   if (gdk_texture_set_render_data (texture, self, t, gsk_gl_driver_release_texture))
     t->user = texture;
@@ -547,6 +545,9 @@ gsk_gl_driver_get_texture_for_texture (GskGLDriver *self,
                                            surface,
                                            min_filter,
                                            mag_filter);
+  gdk_gl_context_label_object_printf (self->gl_context, GL_TEXTURE, t->texture_id,
+                                      "GdkTexture<%p> %d", texture, t->texture_id);
+
   cairo_surface_destroy (surface);
 
   return t->texture_id;

gsk/gl/gskglrenderer.c

@@ -326,6 +326,7 @@ struct _GskGLRenderer
       Program unblurred_outset_shadow_program;
       Program border_program;
       Program cross_fade_program;
+      Program blend_program;
     };
   };
 
@@ -479,14 +480,14 @@ render_fallback_node (GskGLRenderer       *self,
   texture_id = gsk_gl_driver_create_texture (self->gl_driver,
                                              surface_width,
                                              surface_height);
-  gdk_gl_context_label_object_printf  (self->gl_context, GL_TEXTURE, texture_id,
-                                       "Fallback %s %d", node->node_class->type_name, texture_id);
-
   gsk_gl_driver_bind_source_texture (self->gl_driver, texture_id);
   gsk_gl_driver_init_texture_with_surface (self->gl_driver,
                                            texture_id,
                                            surface,
                                            GL_NEAREST, GL_NEAREST);
+  gdk_gl_context_label_object_printf  (self->gl_context, GL_TEXTURE, texture_id,
+                                       "Fallback %s %d", node->node_class->type_name, texture_id);
+
 
   cairo_surface_destroy (surface);
 
@@ -1431,10 +1432,10 @@ render_outset_shadow_node (GskGLRenderer       *self,
       GskRoundedRect blit_clip;
 
       texture_id = gsk_gl_driver_create_texture (self->gl_driver, texture_width, texture_height);
-      gdk_gl_context_label_object_printf (self->gl_context, GL_TEXTURE, texture_id,
-                                          "Outset Shadow Temp %d", texture_id);
       gsk_gl_driver_bind_source_texture (self->gl_driver, texture_id);
       gsk_gl_driver_init_texture_empty (self->gl_driver, texture_id);
+      gdk_gl_context_label_object_printf (self->gl_context, GL_TEXTURE, texture_id,
+                                          "Outset Shadow Temp %d", texture_id);
       render_target = gsk_gl_driver_create_render_target (self->gl_driver, texture_id, FALSE, FALSE);
       gdk_gl_context_label_object_printf  (self->gl_context, GL_FRAMEBUFFER, render_target,
                                            "Outset Shadow FB Temp %d", render_target);
@@ -1468,10 +1469,10 @@ render_outset_shadow_node (GskGLRenderer       *self,
       });
 
       blurred_texture_id = gsk_gl_driver_create_permanent_texture (self->gl_driver, texture_width, texture_height);
-      gdk_gl_context_label_object_printf (self->gl_context, GL_TEXTURE, blurred_texture_id,
-                                          "Outset Shadow Cache %d", blurred_texture_id);
       gsk_gl_driver_bind_source_texture (self->gl_driver, blurred_texture_id);
       gsk_gl_driver_init_texture_empty (self->gl_driver, blurred_texture_id);
+      gdk_gl_context_label_object_printf (self->gl_context, GL_TEXTURE, blurred_texture_id,
+                                          "Outset Shadow Cache %d", blurred_texture_id);
       blurred_render_target = gsk_gl_driver_create_render_target (self->gl_driver, blurred_texture_id, TRUE, TRUE);
       gdk_gl_context_label_object_printf  (self->gl_context, GL_FRAMEBUFFER, render_target,
                                            "Outset Shadow Cache FB %d", render_target);
@@ -1900,6 +1901,54 @@ render_cross_fade_node (GskGLRenderer       *self,
   ops_draw (builder, vertex_data);
 }
 
+static inline void
+render_blend_node (GskGLRenderer   *self,
+                   GskRenderNode   *node,
+                   RenderOpBuilder *builder)
+{
+  GskRenderNode *top_child = gsk_blend_node_get_top_child (node);
+  GskRenderNode *bottom_child = gsk_blend_node_get_bottom_child (node);
+  const float min_x = builder->dx + node->bounds.origin.x;
+  const float min_y = builder->dy + node->bounds.origin.y;
+  const float max_x = min_x + node->bounds.size.width;
+  const float max_y = min_y + node->bounds.size.height;
+  int top_texture_id;
+  int bottom_texture_id;
+  gboolean is_offscreen1, is_offscreen2;
+  RenderOp op;
+  const GskQuadVertex vertex_data[GL_N_VERTICES] = {
+    { { min_x, min_y }, { 0, 1 }, },
+    { { min_x, max_y }, { 0, 0 }, },
+    { { max_x, min_y }, { 1, 1 }, },
+
+    { { max_x, max_y }, { 1, 0 }, },
+    { { min_x, max_y }, { 0, 0 }, },
+    { { max_x, min_y }, { 1, 1 }, },
+  };
+
+  /* TODO: We create 2 textures here as big as the blend node, but both the
+   * start and the end node might be a lot smaller than that. */
+  add_offscreen_ops (self, builder,
+                     &node->bounds,
+                     bottom_child,
+                     &bottom_texture_id, &is_offscreen1,
+                     FORCE_OFFSCREEN | RESET_CLIP);
+
+  add_offscreen_ops (self, builder,
+                     &node->bounds,
+                     top_child,
+                     &top_texture_id, &is_offscreen2,
+                     FORCE_OFFSCREEN | RESET_CLIP);
+
+  ops_set_program (builder, &self->blend_program);
+  ops_set_texture (builder, bottom_texture_id);
+  op.op = OP_CHANGE_BLEND;
+  op.blend.source2 = top_texture_id;
+  op.blend.mode = gsk_blend_node_get_blend_mode (node);
+  ops_add (builder, &op);
+  ops_draw (builder, vertex_data);
+}
+
 static inline void
 apply_viewport_op (const Program  *program,
                    const RenderOp *op)
@@ -2174,6 +2223,18 @@ apply_cross_fade_op (const Program  *program,
   glUniform1f (program->cross_fade.progress_location, op->cross_fade.progress);
 }
 
+static inline void
+apply_blend_op (const Program  *program,
+                const RenderOp *op)
+{
+  /* End texture id */
+  glUniform1i (program->blend.source2_location, 1);
+  glActiveTexture (GL_TEXTURE0 + 1);
+  glBindTexture (GL_TEXTURE_2D, op->blend.source2);
+  /* progress */
+  glUniform1i (program->blend.mode_location, op->blend.mode);
+}
+
 static void
 gsk_gl_renderer_dispose (GObject *gobject)
 {
@@ -2206,6 +2267,7 @@ gsk_gl_renderer_create_programs (GskGLRenderer  *self,
     { "unblurred outset shadow",   "unblurred_outset_shadow.fs.glsl" },
     { "border",          "border.fs.glsl" },
     { "cross fade",      "cross_fade.fs.glsl" },
+    { "blend",           "blend.fs.glsl" },
   };
 
   builder = gsk_shader_builder_new ();
@@ -2336,6 +2398,10 @@ gsk_gl_renderer_create_programs (GskGLRenderer  *self,
   INIT_PROGRAM_UNIFORM_LOCATION (cross_fade, progress);
   INIT_PROGRAM_UNIFORM_LOCATION (cross_fade, source2);
 
+  /* blend */
+  INIT_PROGRAM_UNIFORM_LOCATION (blend, source2);
+  INIT_PROGRAM_UNIFORM_LOCATION (blend, mode);
+
   g_object_unref (builder);
   return TRUE;
 }
@@ -2588,8 +2654,11 @@ gsk_gl_renderer_add_render_ops (GskGLRenderer   *self,
       render_cross_fade_node (self, node, builder);
     break;
 
-    case GSK_REPEATING_LINEAR_GRADIENT_NODE:
     case GSK_BLEND_NODE:
+      render_blend_node (self, node, builder);
+    break;
+
+    case GSK_REPEATING_LINEAR_GRADIENT_NODE:
     case GSK_REPEAT_NODE:
     case GSK_CAIRO_NODE:
     default:
@@ -2855,6 +2924,11 @@ gsk_gl_renderer_render_ops (GskGLRenderer *self,
           apply_cross_fade_op (program, op);
           break;
 
+        case OP_CHANGE_BLEND:
+          g_assert (program == &self->blend_program);
+          apply_blend_op (program, op);
+          break;
+
         case OP_CHANGE_LINEAR_GRADIENT:
           apply_linear_gradient_op (program, op);
           break;

gsk/gl/gskglrenderopsprivate.h

@@ -11,7 +11,7 @@
 #include "gskrendernodeprivate.h"
 
 #define GL_N_VERTICES 6
-#define GL_N_PROGRAMS 11
+#define GL_N_PROGRAMS 12
 
 
 
@@ -61,6 +61,7 @@ enum {
   OP_DUMP_FRAMEBUFFER       =  23,
   OP_PUSH_DEBUG_GROUP       =  24,
   OP_POP_DEBUG_GROUP        =  25,
+  OP_CHANGE_BLEND           =  26,
 };
 
 typedef struct
@@ -136,6 +137,10 @@ typedef struct
       int source2_location;
       int progress_location;
     } cross_fade;
+    struct {
+      int source2_location;
+      int mode_location;
+    } blend;
   };
 
 } Program;
@@ -214,6 +219,10 @@ typedef struct
       float progress;
       int source2;
     } cross_fade;
+    struct {
+      int source2;
+      int mode;
+    } blend;
     struct {
       char *filename;
       int width;

gsk/gskrendernode.c

@@ -42,6 +42,7 @@
 
 #include "gskdebugprivate.h"
 #include "gskrendererprivate.h"
+#include "gskrendernodeparserprivate.h"
 
 #include <graphene-gobject.h>
 
@@ -328,19 +329,11 @@ gsk_render_node_diff (GskRenderNode  *node1,
 GBytes *
 gsk_render_node_serialize (GskRenderNode *node)
 {
-  GVariant *node_variant, *variant;
   GBytes *result;
+  char *str;
 
-  node_variant = gsk_render_node_serialize_node (node);
+  str = gsk_render_node_serialize_to_string (node);
-
+  result = g_bytes_new_take (str, strlen (str));
-  variant = g_variant_new ("(suuv)",
-                           GSK_RENDER_NODE_SERIALIZATION_ID,
-                           (guint32) GSK_RENDER_NODE_SERIALIZATION_VERSION,
-                           (guint32) gsk_render_node_get_node_type (node),
-                           node_variant);
-
-  result = g_variant_get_data_as_bytes (variant);
-  g_variant_unref (variant);
 
   return result;
 }
@@ -394,39 +387,13 @@ gsk_render_node_write_to_file (GskRenderNode *node,
  *     error.
  **/
 GskRenderNode *
-gsk_render_node_deserialize (GBytes  *bytes,
+gsk_render_node_deserialize (GBytes            *bytes,
-                             GError **error)
+                             GskParseErrorFunc  error_func,
+                             gpointer           user_data)
 {
-  char *id_string;
-  guint32 version, node_type;
-  GVariant *variant, *node_variant;
   GskRenderNode *node = NULL;
 
-  variant = g_variant_new_from_bytes (G_VARIANT_TYPE ("(suuv)"), bytes, FALSE);
+  node = gsk_render_node_deserialize_from_bytes (bytes, error_func, user_data);
-
-  g_variant_get (variant, "(suuv)", &id_string, &version, &node_type, &node_variant);
-
-  if (!g_str_equal (id_string, GSK_RENDER_NODE_SERIALIZATION_ID))
-    {
-      g_set_error (error, GSK_SERIALIZATION_ERROR, GSK_SERIALIZATION_UNSUPPORTED_FORMAT,
-                   "Data not in GskRenderNode serialization format.");
-      goto out;
-    }
-
-  if (version != GSK_RENDER_NODE_SERIALIZATION_VERSION)
-    {
-      g_set_error (error, GSK_SERIALIZATION_ERROR, GSK_SERIALIZATION_UNSUPPORTED_VERSION,
-                   "Format version %u not supported.", version);
-      goto out;
-    }
-
-  node = gsk_render_node_deserialize_node (node_type, node_variant, error);
-
-out:
-  g_free (id_string);
-  g_variant_unref (node_variant);
-  g_variant_unref (variant);
 
   return node;
 }
-

gsk/gskrendernode.h

@@ -25,6 +25,7 @@
 
 #include <gsk/gskroundedrect.h>
 #include <gsk/gsktypes.h>
+#include <gtk/css/gtkcss.h>
 
 G_BEGIN_DECLS
 
@@ -52,6 +53,10 @@ struct _GskShadow
   float radius;
 };
 
+typedef void           (* GskParseErrorFunc)                    (const GtkCssSection *section,
+                                                                 const GError        *error,
+                                                                 gpointer             user_data);
+
 GDK_AVAILABLE_IN_ALL
 GType                   gsk_render_node_get_type                (void) G_GNUC_CONST;
 
@@ -81,8 +86,9 @@ gboolean                gsk_render_node_write_to_file           (GskRenderNode *
                                                                  const char    *filename,
                                                                  GError       **error);
 GDK_AVAILABLE_IN_ALL
-GskRenderNode *         gsk_render_node_deserialize             (GBytes        *bytes,
+GskRenderNode *         gsk_render_node_deserialize             (GBytes            *bytes,
-                                                                 GError       **error);
+                                                                 GskParseErrorFunc  error_func,
+                                                                 gpointer           user_data);
 
 GDK_AVAILABLE_IN_ALL
 GskRenderNode *         gsk_debug_node_new                      (GskRenderNode            *child,

gsk/gskrendernodeparserprivate.h

@@ -0,0 +1,12 @@
+
+#ifndef __GSK_RENDER_NODE_PARSER_PRIVATE_H__
+#define __GSK_RENDER_NODE_PARSER_PRIVATE_H__
+
+#include "gskrendernode.h"
+
+GskRenderNode * gsk_render_node_deserialize_from_bytes  (GBytes            *bytes,
+                                                         GskParseErrorFunc  error_func,
+                                                         gpointer           user_data);
+char *          gsk_render_node_serialize_to_string     (GskRenderNode *root);
+
+#endif

gsk/gskrendernodeprivate.h

@@ -33,9 +33,6 @@ struct _GskRenderNodeClass
   void            (* diff)        (GskRenderNode  *node1,
                                    GskRenderNode  *node2,
                                    cairo_region_t *region);
-  GVariant *      (* serialize)   (GskRenderNode  *node);
-  GskRenderNode * (* deserialize) (GVariant       *variant,
-                                   GError        **error);
 };
 
 GskRenderNode * gsk_render_node_new              (const GskRenderNodeClass  *node_class,
@@ -50,11 +47,6 @@ void            gsk_render_node_diff_impossible  (GskRenderNode             *nod
                                                   GskRenderNode             *node2,
                                                   cairo_region_t            *region);
 
-GVariant *      gsk_render_node_serialize_node   (GskRenderNode             *node);
-GskRenderNode * gsk_render_node_deserialize_node (GskRenderNodeType          type,
-                                                  GVariant                  *variant,
-                                                  GError                   **error);
-
 GskRenderNode * gsk_cairo_node_new_for_surface   (const graphene_rect_t    *bounds,
                                                   cairo_surface_t          *surface);
 

gsk/gsktransform.c

@@ -1695,6 +1695,7 @@ gsk_transform_parser_parse (GtkCssParser  *parser,
   if (gtk_css_token_is_ident (token, "none"))
     {
       gtk_css_parser_consume_token (parser);
+
       *out_transform = NULL;
       return TRUE;
     }
@@ -1902,6 +1903,7 @@ gsk_transform_parse (const char    *string,
       result = FALSE;
     }
   gtk_css_parser_unref (parser);
+
   g_bytes_unref (bytes);
 
   return result; 

gsk/meson.build

@@ -11,6 +11,7 @@ gsk_private_gl_shaders = [
   'resources/glsl/unblurred_outset_shadow.fs.glsl',
   'resources/glsl/border.fs.glsl',
   'resources/glsl/cross_fade.fs.glsl',
+  'resources/glsl/blend.fs.glsl',
   'resources/glsl/es2_common.fs.glsl',
   'resources/glsl/es2_common.vs.glsl',
   'resources/glsl/gl3_common.fs.glsl',
@@ -34,6 +35,7 @@ gsk_private_sources = files([
   'gskdebug.c',
   'gskprivate.c',
   'gskprofiler.c',
+  'gskrendernodeparser.c',
   'gl/gskshaderbuilder.c',
   'gl/gskglprofiler.c',
   'gl/gskglrenderer.c',

gsk/resources/glsl/blend.fs.glsl

@@ -0,0 +1,287 @@
+uniform int u_mode;
+uniform sampler2D u_source2;
+
+float
+combine (float source, float backdrop)
+{
+  return source + backdrop * (1 - source);
+}
+
+vec4
+composite (vec4 Cs, vec4 Cb, vec3 B)
+{
+  float ao = Cs.a + Cb.a * (1 - Cs.a);
+  vec3 Co = (Cs.a*(1 - Cb.a)*Cs.rgb + Cs.a*Cb.a*B + (1 - Cs.a)*Cb.a*Cb.rgb) / ao;
+  return vec4(Co, ao);
+}
+
+vec4
+normal (vec4 Cs, vec4 Cb)
+{
+  return composite (Cs, Cb, Cs.rgb);
+}
+
+vec4
+multiply (vec4 Cs, vec4 Cb)
+{
+  return composite (Cs, Cb, Cs.rgb * Cb.rgb);
+}
+
+vec4
+difference (vec4 Cs, vec4 Cb)
+{
+  return composite (Cs, Cb, abs(Cs.rgb - Cb.rgb));
+}
+
+vec4
+screen (vec4 Cs, vec4 Cb)
+{
+  return composite (Cs, Cb, Cs.rgb + Cb.rgb - Cs.rgb * Cb.rgb);
+}
+
+float
+hard_light (float source, float backdrop)
+{
+  if (source <= 0.5)
+    return 2 * backdrop * source;
+  else
+    return 2 * (backdrop + source - backdrop * source) - 1;
+}
+
+vec4
+hard_light (vec4 Cs, vec4 Cb)
+{
+  vec3 B = vec3 (hard_light (Cs.r, Cb.r),
+                 hard_light (Cs.g, Cb.g),
+                 hard_light (Cs.b, Cb.b));
+  return composite (Cs, Cb, B);
+}
+
+float
+soft_light (float source, float backdrop)
+{
+  float db;
+
+  if (backdrop <= 0.25)
+    db = ((16 * backdrop - 12) * backdrop + 4) * backdrop;
+  else
+    db = sqrt (backdrop);
+
+  if (source <= 0.5)
+    return backdrop - (1 - 2 * source) * backdrop * (1 - backdrop);
+  else
+    return backdrop + (2 * source - 1) * (db - backdrop);
+}
+
+vec4
+soft_light (vec4 Cs, vec4 Cb)
+{
+  vec3 B = vec3 (soft_light (Cs.r, Cb.r),
+                 soft_light (Cs.g, Cb.g),
+                 soft_light (Cs.b, Cb.b));
+  return composite (Cs, Cb, B);
+}
+
+vec4
+overlay (vec4 Cs, vec4 Cb)
+{
+  vec3 B = vec3 (hard_light (Cb.r, Cs.r),
+                 hard_light (Cb.g, Cs.g),
+                 hard_light (Cb.b, Cs.b));
+  return composite (Cs, Cb, B);
+}
+
+vec4
+darken (vec4 Cs, vec4 Cb)
+{
+  vec3 B = min (Cs.rgb, Cb.rgb);
+  return composite (Cs, Cb, B);
+}
+
+vec4
+lighten (vec4 Cs, vec4 Cb)
+{
+  vec3 B = max (Cs.rgb, Cb.rgb);
+  return composite (Cs, Cb, B);
+}
+
+float
+color_dodge (float source, float backdrop)
+{
+  return (source == 1.0) ? source : min (backdrop / (1.0 - source), 1.0);
+}
+
+vec4
+color_dodge (vec4 Cs, vec4 Cb)
+{
+  vec3 B = vec3 (color_dodge (Cs.r, Cb.r),
+                 color_dodge (Cs.g, Cb.g),
+                 color_dodge (Cs.b, Cb.b));
+  return composite (Cs, Cb, B);
+}
+
+
+float
+color_burn (float source, float backdrop)
+{
+  return (source == 0.0) ? source : max ((1.0 - ((1.0 - backdrop) / source)), 0.0);
+}
+
+vec4
+color_burn (vec4 Cs, vec4 Cb)
+{
+  vec3 B = vec3 (color_burn (Cs.r, Cb.r),
+                 color_burn (Cs.g, Cb.g),
+                 color_burn (Cs.b, Cb.b));
+  return composite (Cs, Cb, B);
+}
+
+vec4
+exclusion (vec4 Cs, vec4 Cb)
+{
+  vec3 B = Cb.rgb + Cs.rgb - 2.0 * Cb.rgb * Cs.rgb;
+  return composite (Cs, Cb, B);
+}
+
+float
+lum (vec3 c)
+{
+  return 0.3 * c.r + 0.59 * c.g + 0.11 * c.b;
+}
+
+vec3
+clip_color (vec3 c)
+{
+  float l = lum (c);
+  float n = min (c.r, min (c.g, c.b));
+  float x = max (c.r, max (c.g, c.b));
+  if (n < 0) c = l + (((c - l) * l) / (l - n));
+  if (x > 1) c = l + (((c - l) * (1 - l)) / (x - l));
+  return c;
+}
+
+vec3
+set_lum (vec3 c, float l)
+{
+  float d = l - lum (c);
+  return clip_color (vec3 (c.r + d, c.g + d, c.b + d));
+}
+
+float
+sat (vec3 c)
+{
+  return max (c.r, max (c.g, c.b)) - min (c.r, min (c.g, c.b));
+}
+
+vec3
+set_sat (vec3 c, float s)
+{
+  float cmin = min (c.r, min (c.g, c.b));
+  float cmax = max (c.r, max (c.g, c.b));
+  vec3 res;
+
+  if (cmax == cmin)
+    res = vec3 (0, 0, 0);
+  else
+    {
+      if (c.r == cmax)
+        {
+          if (c.g == cmin)
+            {
+              res.b = ((c.b - cmin) * s) / (cmax - cmin);
+              res.g = 0;
+            }
+          else
+            {
+              res.g = ((c.g - cmin) * s) / (cmax - cmin);
+              res.b = 0;
+            }
+          res.r = s;
+        }
+      else if (c.g == cmax)
+        {
+          if (c.r == cmin)
+            {
+              res.b = ((c.b - cmin) * s) / (cmax - cmin);
+              res.r = 0;
+            }
+          else
+            {
+              res.r = ((c.r - cmin) * s) / (cmax - cmin);
+              res.b = 0;
+            }
+          res.g = s;
+        }
+      else
+        {
+          if (c.r == cmin)
+            {
+              res.g = ((c.g - cmin) * s) / (cmax - cmin);
+              res.r = 0;
+            }
+          else
+            {
+              res.r = ((c.r - cmin) * s) / (cmax - cmin);
+              res.g = 0;
+            }
+          res.b = s;
+        }
+    }
+  return res;
+}
+
+vec4
+color (vec4 Cs, vec4 Cb)
+{
+  vec3 B = set_lum (Cs.rgb, lum (Cb.rgb));
+  return composite (Cs, Cb, B);
+}
+
+vec4
+hue (vec4 Cs, vec4 Cb)
+{
+  vec3 B = set_lum (set_sat (Cs.rgb, sat (Cb.rgb)), lum (Cb.rgb));
+  return composite (Cs, Cb, B);
+}
+
+vec4
+saturation (vec4 Cs, vec4 Cb)
+{
+  vec3 B = set_lum (set_sat (Cb.rgb, sat (Cs.rgb)), lum (Cb.rgb));
+  return composite (Cs, Cb, B);
+}
+
+vec4
+luminosity (vec4 Cs, vec4 Cb)
+{
+  vec3 B = set_lum (Cb.rgb, lum (Cs.rgb));
+  return composite (Cs, Cb, B);
+}
+
+void main() {
+  vec4 bottom_color = Texture(u_source, vUv);
+  vec4 top_color = Texture(u_source2, vUv);
+
+  vec4 result;
+  switch(u_mode) {
+    case 0:  result = normal(bottom_color, top_color);      break;
+    case 1:  result = multiply(bottom_color, top_color);    break;
+    case 2:  result = screen(bottom_color, top_color);      break;
+    case 3:  result = overlay(bottom_color, top_color);     break;
+    case 4:  result = darken(bottom_color, top_color);      break;
+    case 5:  result = lighten(bottom_color, top_color);     break;
+    case 6:  result = color_dodge(bottom_color, top_color); break;
+    case 7:  result = color_burn(bottom_color, top_color);  break;
+    case 8:  result = hard_light(bottom_color, top_color);  break;
+    case 9:  result = soft_light(bottom_color, top_color);  break;
+    case 10: result = difference(bottom_color, top_color);  break;
+    case 11: result = exclusion(bottom_color, top_color);   break;
+    case 12: result = color(bottom_color, top_color);       break;
+    case 13: result = hue(bottom_color, top_color);         break;
+    case 14: result = saturation(bottom_color, top_color);  break;
+    case 15: result = luminosity(bottom_color, top_color);  break;
+    default: discard;
+  }
+
+  setOutputColor(result * u_alpha);
+}

gtk/gtkcssprovider.h

@@ -30,6 +30,29 @@ G_BEGIN_DECLS
 #define GTK_IS_CSS_PROVIDER_CLASS(c)  (G_TYPE_CHECK_CLASS_TYPE    ((c), GTK_TYPE_CSS_PROVIDER))
 #define GTK_CSS_PROVIDER_GET_CLASS(o) (G_TYPE_INSTANCE_GET_CLASS  ((o), GTK_TYPE_CSS_PROVIDER, GtkCssProviderClass))
 
+/**
+ * GtkCssProviderError:
+ * @GTK_CSS_PROVIDER_ERROR_FAILED: Failed.
+ * @GTK_CSS_PROVIDER_ERROR_SYNTAX: Syntax error.
+ * @GTK_CSS_PROVIDER_ERROR_IMPORT: Import error.
+ * @GTK_CSS_PROVIDER_ERROR_NAME: Name error.
+ * @GTK_CSS_PROVIDER_ERROR_DEPRECATED: Deprecation error.
+ * @GTK_CSS_PROVIDER_ERROR_UNKNOWN_VALUE: Unknown value.
+ * @GTK_CSS_PROVIDER_WARN_GENERAL: A general warning.
+ *
+ * Error codes for %GTK_CSS_PROVIDER_ERROR.
+ */
+typedef enum
+{
+  GTK_CSS_PROVIDER_ERROR_FAILED,
+  GTK_CSS_PROVIDER_ERROR_SYNTAX,
+  GTK_CSS_PROVIDER_ERROR_IMPORT,
+  GTK_CSS_PROVIDER_ERROR_NAME,
+  GTK_CSS_PROVIDER_ERROR_DEPRECATED,
+  GTK_CSS_PROVIDER_ERROR_UNKNOWN_VALUE,
+  GTK_CSS_PROVIDER_WARN_GENERAL,
+} GtkCssProviderError;
+
 typedef struct _GtkCssProvider GtkCssProvider;
 typedef struct _GtkCssProviderClass GtkCssProviderClass;
 typedef struct _GtkCssProviderPrivate GtkCssProviderPrivate;

tests/rendernode.c

@@ -13,6 +13,19 @@ static GOptionEntry options[] = {
   { NULL }
 };
 
+static void
+deserialize_error_func (const GtkCssSection *section,
+                        const GError        *error,
+                        gpointer             user_data)
+{
+  char *section_str = gtk_css_section_to_string (section);
+
+  g_warning ("Error at %s: %s", section_str, error->message);
+
+  free (section_str);
+}
+
+
 int
 main(int argc, char **argv)
 {
@@ -66,7 +79,7 @@ main(int argc, char **argv)
     }
 
   start = g_get_monotonic_time ();
-  node = gsk_render_node_deserialize (bytes, &error);
+  node = gsk_render_node_deserialize (bytes, deserialize_error_func, NULL);
   end = g_get_monotonic_time ();
   if (benchmark)
     {
@@ -78,8 +91,6 @@ main(int argc, char **argv)
 
   if (node == NULL)
     {
-      g_printerr ("Invalid node file: %s\n", error->message);
-      g_clear_error (&error);
       return 1;
     }
 

tests/showrendernode.c

@@ -108,6 +108,18 @@ gtk_node_view_class_init (GtkNodeViewClass *klass)
   widget_class->snapshot = gtk_node_view_snapshot;
 }
 
+static void
+deserialize_error_func (const GtkCssSection *section,
+                        const GError        *error,
+                        gpointer             user_data)
+{
+  char *section_str = gtk_css_section_to_string (section);
+
+  g_warning ("Error at %s: %s", section_str, error->message);
+
+  free (section_str);
+}
+
 int
 main (int argc, char **argv)
 {
@@ -152,7 +164,7 @@ main (int argc, char **argv)
     }
 
   bytes = g_bytes_new_take (contents, len);
-  GTK_NODE_VIEW (nodeview)->node = gsk_render_node_deserialize (bytes, &error);
+  GTK_NODE_VIEW (nodeview)->node = gsk_render_node_deserialize (bytes, deserialize_error_func, NULL);
   g_bytes_unref (bytes);
 
   if (GTK_NODE_VIEW (nodeview)->node == NULL)

testsuite/gsk/compare-render.c

@@ -54,6 +54,18 @@ save_image (cairo_surface_t *surface,
   g_free (filename);
 }
 
+static void
+deserialize_error_func (const GtkCssSection *section,
+                        const GError        *error,
+                        gpointer             user_data)
+{
+  char *section_str = gtk_css_section_to_string (section);
+
+  g_error ("Error at %s: %s", section_str, error->message);
+
+  free (section_str);
+}
+
 /*
  * Arguments:
  *   1) .node file to compare
@@ -101,7 +113,7 @@ main (int argc, char **argv)
       }
 
     bytes = g_bytes_new_take (contents, len);
-    node = gsk_render_node_deserialize (bytes, &error);
+    node = gsk_render_node_deserialize (bytes, deserialize_error_func, NULL);
     g_bytes_unref (bytes);
 
     g_assert_no_error (error);

testsuite/gsk/compare/clip-coordinates-3d.node

@@ -0,0 +1,19 @@
+transform {
+  /* adding the perspective line here turns the matrix from a 2D
+     category into a 3D category. It does not have any visual effect. */
+  transform: perspective(200) scale(2);
+  child: container {
+    color {
+      bounds: 0 0 50 50;
+      color: transparent;
+    }
+
+    clip {
+      clip: 10 10 30 30;
+      child: color {
+        bounds: 0 0 50 50;
+        color: red;
+      }
+    }
+  }
+}

testsuite/gsk/compare/clipped_rounded_clip.node

@@ -0,0 +1,34 @@
+color {
+  color: white;
+  bounds: 50 70 80 90;
+}
+
+clip {
+  clip: 60 80 60 70;
+  child: rounded-clip {
+    clip: 20 50 100 100 / 50;
+    child: color {
+      bounds: 20 50 100 100;
+      color: red;
+    }
+  }
+}
+
+/* The actual rounded portion of the clip is irrelevant
+ * for this test case. This just ensures that
+ * offscreen-drawn clips work and have the correct
+ * size, color, etc.
+ */
+debug {
+  message: "clipped out area";
+  child: container {
+    color {
+      bounds: 115 80 5 45;
+      color: black;
+    }
+    color {
+      bounds: 60 120 60 30;
+      color: black;
+    }
+  }
+}

testsuite/gsk/compare/opacity_clip.node

@@ -0,0 +1,36 @@
+color {
+  bounds: 40 40 70 70;
+  color: transparent;
+}
+
+clip {
+  clip: 50 50 50 50;
+  child: opacity {
+    opacity: 0.4;
+    child: rounded-clip {
+      clip: 50 50 100 100 / 50;
+      child: color {
+        bounds: 50 50 100 100;
+        color: red;
+      }
+    }
+  }
+}
+
+debug {
+  message: "clipped out area";
+  child: container {
+    color {
+      bounds: 50 70 10 30;
+      color: black;
+    }
+    color {
+      bounds: 55 55 20 20;
+      color: black;
+    }
+    color {
+      bounds: 70 50 30 10;
+      color: black;
+    }
+  }
+}

testsuite/gsk/compare/outset_shadow_offset_both.node

@@ -0,0 +1,8 @@
+outset-shadow {
+  outline: 100 100 100 100;
+  color: black;
+  dx: -100;
+  dy: 100;
+  spread: 10;
+  blur: 0;
+}

testsuite/gsk/compare/outset_shadow_offset_x.node

@@ -0,0 +1,8 @@
+outset-shadow {
+  outline: 100 100 100 100;
+  color: black;
+  dx: 10;
+  dy: 0;
+  spread: 10;
+  blur: 0;
+}

testsuite/gsk/compare/outset_shadow_offset_y.node

@@ -0,0 +1,8 @@
+outset-shadow {
+  outline: 100 100 100 100;
+  color: black;
+  dx: 0;
+  dy: 10;
+  spread: 10;
+  blur: 0;
+}

testsuite/gsk/compare/outset_shadow_simple.node

@@ -0,0 +1,8 @@
+outset-shadow {
+  outline: 100 100 100 100;
+  color: black;
+  dx: 0;
+  dy: 0;
+  spread: 10;
+  blur: 0;
+}

testsuite/gsk/gl/cross-fade-in-opacity.node

@@ -0,0 +1,23 @@
+/* Background */
+color {
+  bounds: 0 0 200 200;
+  color: white;
+}
+
+/* It is important that the following node structure leaves the
+ * start child of the cross-fade node invisible. */
+opacity {
+  opacity: 0.4;
+
+  child: cross-fade {
+    start: color {
+      color: blue;
+      bounds: 0 0 100 100;
+    }
+    end: color {
+      color: red;
+      bounds: 100 100 100 100;
+    }
+    progress: 1.0;
+  }
+}

testsuite/gsk/gl/shadow-in-opacity.node

@@ -0,0 +1,24 @@
+
+/*
+  The opacity node should affect both the shadow node child
+  (the node that's NOT colored) and the actual shadow.
+  I.e. the output should be entirely empty.
+*/
+opacity {
+  opacity: 0;
+
+  child: shadow {
+    child: cross-fade {
+      start: color {
+        color: blue;
+        bounds: 0 0 100 100;
+      }
+      end: color {
+        color: red;
+        bounds: 100 100 100 100;
+      }
+      progress: 0;
+    }
+    shadows: green 200 0 0;
+  }
+}