compositor, clients: make damage double-buffered

This change depends on the Wayland commit
"protocol: double-buffered state for wl_surface".

Implement double-buffering of damage in the compositor as required by
the new protocol.

Ensure all Weston demo clients call wl_surface_commit() after
wl_surface_damage().

Mesa does not need a fix for this, as the patch adding
wl_surface_commit() call to Mesa already takes care of damage, too;
Mesa commit: "wayland: use wl_surface_commit()"

Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>

clients/simple-touch.c

@@ -142,6 +142,10 @@ touch_paint(struct touch *touch, int32_t x, int32_t y, int32_t id)
 	p[2] = c;
 
 	wl_surface_damage(touch->surface, x - 2, y - 2, 5, 5);
+	/* todo: We could queue up more damage before committing, if there
+	 * are more input events to handle.
+	 */
+	wl_surface_commit(touch->surface);
 }
 
 static void

clients/smoke.c

@@ -223,6 +223,7 @@ redraw_handler(struct widget *widget, void *data)
 
 	callback = wl_surface_frame(window_get_wl_surface(smoke->window));
 	wl_callback_add_listener(callback, &listener, smoke);
+	wl_surface_commit(window_get_wl_surface(smoke->window));
 }
 
 static int

src/compositor.c

@@ -274,6 +274,7 @@ weston_surface_create(struct weston_compositor *compositor)
 
 	surface->pending.buffer_destroy_listener.notify =
 		surface_handle_pending_buffer_destroy;
+	pixman_region32_init(&surface->pending.damage);
 
 	return surface;
 }
@@ -780,6 +781,8 @@ destroy_surface(struct wl_resource *resource)
 	if (weston_surface_is_mapped(surface))
 		weston_surface_unmap(surface);
 
+	pixman_region32_fini(&surface->pending.damage);
+
 	if (surface->pending.buffer)
 		wl_list_remove(&surface->pending.buffer_destroy_listener.link);
 
@@ -1166,11 +1169,11 @@ surface_damage(struct wl_client *client,
 	       struct wl_resource *resource,
 	       int32_t x, int32_t y, int32_t width, int32_t height)
 {
-	struct weston_surface *es = resource->data;
+	struct weston_surface *surface = resource->data;
 
-	pixman_region32_union_rect(&es->damage, &es->damage,
+	pixman_region32_union_rect(&surface->pending.damage,
+				   &surface->pending.damage,
 				   x, y, width, height);
-	weston_surface_schedule_repaint(es);
 }
 
 static void
@@ -1265,6 +1268,12 @@ surface_commit(struct wl_client *client, struct wl_resource *resource)
 	if (surface->buffer && surface->configure)
 		surface->configure(surface, surface->pending.sx,
 				   surface->pending.sy);
+
+	/* wl_surface.damage */
+	pixman_region32_union(&surface->damage, &surface->damage,
+			      &surface->pending.damage);
+	empty_region(&surface->pending.damage);
+	weston_surface_schedule_repaint(surface);
 }
 
 static const struct wl_surface_interface surface_interface = {

src/compositor.h

@@ -474,6 +474,9 @@ struct weston_surface {
 		struct wl_listener buffer_destroy_listener;
 		int32_t sx;
 		int32_t sy;
+
+		/* wl_surface.damage */
+		pixman_region32_t damage;
 	} pending;
 
 	/*