Files
gtk/demos/gtk-demo/path_sweep.c
2023-09-23 20:14:45 -04:00

320 lines
8.2 KiB
C

/* Path/Sweep
*
* This demo shows how path intersections can be used.
*
* 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_SWEEP (gtk_path_sweep_get_type ())
G_DECLARE_FINAL_TYPE (GtkPathSweep, gtk_path_sweep, GTK, PATH_SWEEP, GtkWidget)
#define POINT_SIZE 8
enum {
PROP_0,
PROP_PATH,
N_PROPS
};
struct _GtkPathSweep
{
GtkWidget parent_instance;
GskPath *path;
graphene_rect_t bounds;
float y_pos;
gboolean in;
};
struct _GtkPathSweepClass
{
GtkWidgetClass parent_class;
};
static GParamSpec *properties[N_PROPS] = { NULL, };
G_DEFINE_TYPE (GtkPathSweep, gtk_path_sweep, GTK_TYPE_WIDGET)
static gboolean
intersection_cb (GskPath *path1,
const GskPathPoint *point1,
GskPath *path2,
const GskPathPoint *point2,
GskPathIntersection kind,
gpointer data)
{
GskPathBuilder *builder = data;
graphene_point_t p;
gsk_path_point_get_position (point1, path1, &p);
gsk_path_builder_add_circle (builder, &p, 4);
return TRUE;
}
static GskPath *
get_intersection_path (GskPath *path1,
GskPath *path2)
{
GskPathBuilder *builder = gsk_path_builder_new ();
gsk_path_foreach_intersection (path1, path2, intersection_cb, builder);
return gsk_path_builder_to_path (builder);
}
static void
gtk_path_sweep_snapshot (GtkWidget *widget,
GtkSnapshot *snapshot)
{
GtkPathSweep *self = GTK_PATH_SWEEP (widget);
GskStroke *stroke;
if (self->path == NULL)
return;
gtk_snapshot_save (snapshot);
stroke = gsk_stroke_new (2.0);
gtk_snapshot_append_stroke (snapshot, self->path, stroke, &(GdkRGBA) { 0, 0, 0, 1 });
if (self->in)
{
graphene_rect_t bounds;
GskPathBuilder *builder;
GskPath *line, *isecs;
gsk_path_get_stroke_bounds (self->path, stroke, &bounds);
builder = gsk_path_builder_new ();
gsk_path_builder_move_to (builder, bounds.origin.x, bounds.origin.y + self->y_pos);
gsk_path_builder_line_to (builder, bounds.origin.x + bounds.size.width, bounds.origin.y + self->y_pos);
line = gsk_path_builder_free_to_path (builder);
gtk_snapshot_append_stroke (snapshot, line, stroke, &(GdkRGBA) { 0, 0, 0, 1 });
isecs = get_intersection_path (self->path, line);
gtk_snapshot_append_fill (snapshot, isecs, GSK_FILL_RULE_WINDING, &(GdkRGBA) { 1, 0, 0, 1 });
gtk_snapshot_append_stroke (snapshot, isecs, stroke, &(GdkRGBA) { 0, 0, 0, 1 });
gsk_path_unref (isecs);
gsk_path_unref (line);
}
gsk_stroke_free (stroke);
gtk_snapshot_restore (snapshot);
}
static void
gtk_path_sweep_measure (GtkWidget *widget,
GtkOrientation orientation,
int for_size,
int *minimum,
int *natural,
int *minimum_baseline,
int *natural_baseline)
{
GtkPathSweep *self = GTK_PATH_SWEEP (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_sweep_set_path (GtkPathSweep *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);
}
gtk_widget_queue_resize (GTK_WIDGET (self));
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_PATH]);
}
static void
gtk_path_sweep_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkPathSweep *self = GTK_PATH_SWEEP (object);
switch (prop_id)
{
case PROP_PATH:
gtk_path_sweep_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_sweep_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkPathSweep *self = GTK_PATH_SWEEP (object);
switch (prop_id)
{
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_sweep_dispose (GObject *object)
{
GtkPathSweep *self = GTK_PATH_SWEEP (object);
g_clear_pointer (&self->path, gsk_path_unref);
G_OBJECT_CLASS (gtk_path_sweep_parent_class)->dispose (object);
}
static void
gtk_path_sweep_class_init (GtkPathSweepClass *klass)
{
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->dispose = gtk_path_sweep_dispose;
object_class->set_property = gtk_path_sweep_set_property;
object_class->get_property = gtk_path_sweep_get_property;
widget_class->snapshot = gtk_path_sweep_snapshot;
widget_class->measure = gtk_path_sweep_measure;
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 void
motion_cb (GtkEventControllerMotion *controller,
double x,
double y,
gpointer data)
{
GtkPathSweep *self = data;
self->y_pos = y;
gtk_widget_queue_draw (GTK_WIDGET (self));
}
static void
enter_cb (GtkEventControllerMotion *controller,
double x,
double y,
gpointer data)
{
GtkPathSweep *self = data;
self->in = TRUE;
self->y_pos = y;
gtk_widget_queue_draw (GTK_WIDGET (self));
}
static void
leave_cb (GtkEventControllerMotion *controller,
gpointer data)
{
GtkPathSweep *self = data;
self->in = FALSE;
gtk_widget_queue_draw (GTK_WIDGET (self));
}
static void
gtk_path_sweep_init (GtkPathSweep *self)
{
GtkEventController *controller;
/* 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_sweep/path_world.txt", 0, NULL);
GskPath *path = gsk_path_parse (g_bytes_get_data (data, NULL));
g_bytes_unref (data);
gtk_path_sweep_set_path (self, path);
gsk_path_unref (path);
controller = gtk_event_controller_motion_new ();
g_signal_connect (controller, "motion", G_CALLBACK (motion_cb), self);
g_signal_connect (controller, "enter", G_CALLBACK (enter_cb), self);
g_signal_connect (controller, "leave", G_CALLBACK (leave_cb), self);
gtk_widget_add_controller (GTK_WIDGET (self), controller);
}
GtkWidget *
gtk_path_sweep_new (void)
{
GtkPathSweep *self;
self = g_object_new (GTK_TYPE_PATH_SWEEP, NULL);
return GTK_WIDGET (self);
}
GtkWidget *
do_path_sweep (GtkWidget *do_widget)
{
static GtkWidget *window = NULL;
if (!window)
{
GtkBuilder *builder;
g_type_ensure (GTK_TYPE_PATH_SWEEP);
builder = gtk_builder_new_from_resource ("/path_sweep/path_sweep.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;
}