[clutter] interactive/touch-events: Optimize touch event drawing

[Emmanuele Bassi <ebassi src gnome org>]

commit 903452d2dfd357e1f6e59b94fc33c6a192415235
Author: Sjoerd Simons <sjoerd simons collabora co uk>
Date:   Fri Jun 22 11:43:52 2012 +0200

    interactive/touch-events: Optimize touch event drawing
    
    The current versions redraws all events on every redraw, which starts
    getting very slow quickly. Instead simply draw only the new events
    except when the cairo surface got reset, in that case redraw all events
    again.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=681584

 tests/interactive/test-touch-events.c |   33 ++++++++++++++++++++++++++++-----
 1 files changed, 28 insertions(+), 5 deletions(-)
---
diff --git a/tests/interactive/test-touch-events.c b/tests/interactive/test-touch-events.c
index 46c6d88..f815450 100644
--- a/tests/interactive/test-touch-events.c
+++ b/tests/interactive/test-touch-events.c
@@ -27,7 +27,10 @@
 #define NUM_COLORS 10
 #define NUM_ACTORS 10
 
-static GSList *events = NULL;
+static GQueue events = G_QUEUE_INIT;
+static GQueue all_events = G_QUEUE_INIT;
+static gboolean new_surface = TRUE;
+
 static const ClutterColor const static_colors[] = {
   { 0xff, 0x00, 0x00, 0xff },   /* red */
   { 0x80, 0x00, 0x00, 0xff },   /* dark red */
@@ -74,19 +77,36 @@ static gboolean
 draw_touches (ClutterCairoTexture *canvas,
               cairo_t             *cr)
 {
-  g_slist_foreach (events, (GFunc) draw_touch, cr);
+  g_queue_foreach (new_surface ? &all_events : &events, (GFunc) draw_touch, cr);
+  g_queue_clear (&events);
+
+  new_surface = FALSE;
 
   return TRUE;
 }
 
+static cairo_surface_t *
+create_surface (ClutterCairoTexture *texture,
+                guint width,
+                guint height,
+                gpointer user_data)
+{
+  new_surface = TRUE;
+
+  return NULL;
+}
+
 static gboolean
 event_cb (ClutterActor *actor, ClutterEvent *event, ClutterActor *canvas)
 {
+  ClutterEvent *copy;
+
   if (event->type != CLUTTER_TOUCH_UPDATE)
     return FALSE;
 
-  events = g_slist_append (events, clutter_event_copy (event));
-
+  copy = clutter_event_copy (event);
+  g_queue_push_tail (&events, copy);
+  g_queue_push_tail (&all_events, copy);
   clutter_actor_queue_redraw (canvas);
 
   return TRUE;
@@ -133,6 +153,7 @@ test_touch_events_main (int argc, char *argv[])
   canvas = clutter_cairo_texture_new (1, 1);
   g_signal_connect (canvas, "paint", G_CALLBACK (canvas_paint), NULL);
   g_signal_connect (canvas, "draw", G_CALLBACK (draw_touches), NULL);
+  g_signal_connect (canvas, "create-surface", G_CALLBACK (create_surface), NULL);
   clutter_cairo_texture_set_auto_resize (CLUTTER_CAIRO_TEXTURE (canvas), TRUE);
   clutter_actor_add_constraint (canvas,
                                 clutter_bind_constraint_new (stage,
@@ -161,7 +182,9 @@ test_touch_events_main (int argc, char *argv[])
 
   clutter_main ();
 
-  g_slist_free_full (events, (GDestroyNotify) clutter_event_free);
+  g_queue_foreach (&all_events, (GFunc) clutter_event_free, NULL);
+  g_queue_clear (&events);
+  g_queue_clear (&all_events);
   g_hash_table_destroy (sequence_to_color);
 
   return EXIT_SUCCESS;