From 903452d2dfd357e1f6e59b94fc33c6a192415235 Mon Sep 17 00:00:00 2001
From: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Date: Fri, 22 Jun 2012 11:43:52 +0200
Subject: [PATCH] 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 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/tests/interactive/test-touch-events.c b/tests/interactive/test-touch-events.c
index 46c6d8809..f81545062 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;