compositor(-drm): Pageflip to fullscreen surfaces
diff --git a/compositor/compositor-drm.c b/compositor/compositor-drm.c
index 10ba65a..7527023 100644
--- a/compositor/compositor-drm.c
+++ b/compositor/compositor-drm.c
@@ -63,6 +63,9 @@
 	uint32_t fb_id[2];
 	EGLImageKHR image[2];
 	uint32_t current;	
+
+	uint32_t fs_surf_fb_id;
+	uint32_t pending_fs_surf_fb_id;
 };
 
 static int
@@ -87,6 +90,8 @@
 	struct drm_output *output = (struct drm_output *) output_base;
 	struct drm_compositor *c =
 		(struct drm_compositor *) output->base.compositor;
+	int ret;
+	uint32_t fb_id = 0;
 
 	if (drm_output_prepare_render(&output->base))
 		return -1;
@@ -94,8 +99,29 @@
 
 	output->current ^= 1;
 
+	if (output->base.scanout_surface) {
+		EGLint handle, stride;
+
+		eglExportDRMImageMESA(c->base.display,
+				      output->base.scanout_surface->image,
+				      NULL, &handle, &stride);
+
+		ret = drmModeAddFB(c->drm.fd,
+				   output->base.width, output->base.height,
+				   32, 32, stride, handle,
+				   &output->fs_surf_fb_id);
+		if (ret)
+			return -1;
+
+		printf("pageflip to fullscreen buffer: %d\n", handle);
+
+		fb_id = output->fs_surf_fb_id;
+	} else {
+		fb_id = output->fb_id[output->current ^ 1];
+	}
+
 	drmModePageFlip(c->drm.fd, output->crtc_id,
-			output->fb_id[output->current ^ 1],
+			fb_id,
 			DRM_MODE_PAGE_FLIP_EVENT, output);
 
 	return 0;
@@ -105,11 +131,52 @@
 page_flip_handler(int fd, unsigned int frame,
 		  unsigned int sec, unsigned int usec, void *data)
 {
-	struct wlsc_output *output = data;
+	struct drm_output *output = (struct drm_output *) data;
+	struct drm_compositor *c =
+		(struct drm_compositor *) output->base.compositor;
 	uint32_t msecs;
 
+	if (output->pending_fs_surf_fb_id) {
+		drmModeRmFB(c->drm.fd, output->pending_fs_surf_fb_id);
+		output->pending_fs_surf_fb_id = 0;
+	}
+
+	if (output->fs_surf_fb_id) {
+		output->pending_fs_surf_fb_id = output->fs_surf_fb_id;
+		output->fs_surf_fb_id = 0;
+	}
+
 	msecs = sec * 1000 + usec / 1000;
-	wlsc_output_finish_frame(output, msecs);
+	wlsc_output_finish_frame(&output->base, msecs);
+}
+
+static int
+drm_output_image_is_scanoutable(struct wlsc_output *output_base,
+				EGLImageKHR image)
+{
+	struct drm_output *output = (struct drm_output *) output_base;
+	struct drm_compositor *c =
+		(struct drm_compositor *) output->base.compositor;
+	EGLint handle, stride;
+	int ret;
+	uint32_t fb_id = 0;
+
+	eglExportDRMImageMESA(c->base.display, image,
+			      NULL, &handle, &stride);
+
+	ret = drmModeAddFB(c->drm.fd,
+			   output->base.width, output->base.height,
+			   32, 32, stride, handle,
+			   &fb_id);
+	if (ret)
+		return 0;
+
+	/* FIXME: change interface to keep this fb_id,
+	 * to be used directly in next pageflip? */
+	if (fb_id)
+		drmModeRmFB(c->drm.fd, fb_id);
+
+	return fb_id != 0;
 }
 
 static void
@@ -285,6 +352,7 @@
 
 	output->base.prepare_render = drm_output_prepare_render;
 	output->base.present = drm_output_present;
+	output->base.image_is_scanoutable = drm_output_image_is_scanoutable;
 
 	wl_list_insert(ec->base.output_list.prev, &output->base.link);
 
diff --git a/compositor/compositor-wayland.c b/compositor/compositor-wayland.c
index 097b23e..93fb577 100644
--- a/compositor/compositor-wayland.c
+++ b/compositor/compositor-wayland.c
@@ -197,6 +197,13 @@
 }
 
 static int
+wayland_output_image_is_scanoutable(struct wlsc_output *output_base,
+				    EGLImageKHR image)
+{
+	return 0;
+}
+
+static int
 wayland_compositor_create_output(struct wayland_compositor *c,
 				 int width, int height)
 {
@@ -246,6 +253,7 @@
 
 	output->base.prepare_render = wayland_output_prepare_render;
 	output->base.present = wayland_output_present;
+	output->base.image_is_scanoutable = wayland_output_image_is_scanoutable;
 
 	wl_list_insert(c->base.output_list.prev, &output->base.link);
 
diff --git a/compositor/compositor-x11.c b/compositor/compositor-x11.c
index 48dd347..e63d6be 100644
--- a/compositor/compositor-x11.c
+++ b/compositor/compositor-x11.c
@@ -191,6 +191,13 @@
 	return 0;
 }
 
+static int
+x11_output_image_is_scanoutable(struct wlsc_output *output_base,
+				EGLImageKHR image)
+{
+	return 0;
+}
+
 static void
 x11_output_set_wm_protocols(struct x11_output *output)
 {
@@ -339,6 +346,7 @@
 
 	output->base.prepare_render = x11_output_prepare_render;
 	output->base.present = x11_output_present;
+	output->base.image_is_scanoutable = x11_output_image_is_scanoutable;
 
 	wl_list_insert(c->base.output_list.prev, &output->base.link);
 
diff --git a/compositor/compositor.c b/compositor/compositor.c
index ed3069d..e88293a 100644
--- a/compositor/compositor.c
+++ b/compositor/compositor.c
@@ -143,6 +143,7 @@
 
 	surface->compositor = compositor;
 	surface->visual = NULL;
+	surface->image = EGL_NO_IMAGE_KHR;
 	surface->x = x;
 	surface->y = y;
 	surface->width = width;
@@ -202,6 +203,10 @@
 	wl_list_remove(&surface->link);
 	glDeleteTextures(1, &surface->texture);
 
+	if (surface->image != EGL_NO_IMAGE_KHR)
+		eglDestroyImageKHR(surface->compositor->display,
+				   surface->image);
+
 	time = get_time();
 	wl_list_for_each_safe(l, next,
 			      &surface->surface.destroy_listener_list, link)
@@ -282,19 +287,17 @@
 {
 	struct wlsc_surface *es = (struct wlsc_surface *) surface;
 	struct wlsc_compositor *ec = es->compositor;
-	EGLImageKHR *image;
 
 	if (buffer->attach) {
 		buffer->attach(buffer, surface);
 	} else {
-		image = eglCreateImageKHR(ec->display, ec->context,
-					  EGL_WAYLAND_BUFFER_WL,
-					  buffer, NULL);
+		es->image = eglCreateImageKHR(ec->display, ec->context,
+					      EGL_WAYLAND_BUFFER_WL,
+					      buffer, NULL);
 
 		glBindTexture(GL_TEXTURE_2D, es->texture);
-		glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, image);
+		glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, es->image);
 		es->visual = buffer->visual;
-		eglDestroyImageKHR(ec->display, image);
 	}
 }
 
@@ -491,6 +494,21 @@
 	compositor->repaint_on_timeout = 1;
 }
 
+static int
+wlsc_surface_is_scanoutable(struct wlsc_surface *es,
+			    struct wlsc_output *output)
+{
+	if (es->width != output->width ||
+	    es->height != output->height ||
+	    es->image == NULL)
+		return 0;
+
+	if (!output->image_is_scanoutable(output, es->image))
+		return 0;
+
+	return 1;
+}
+
 static void
 wlsc_output_repaint(struct wlsc_output *output)
 {
@@ -518,12 +536,20 @@
 			      &output->previous_damage_region);
 	pixman_region32_copy(&output->previous_damage_region, &new_damage);
 
+	output->scanout_surface = NULL;
+
 	es = container_of(ec->surface_list.next, struct wlsc_surface, link);
 	if (es->map_type == WLSC_SURFACE_MAP_FULLSCREEN &&
 	    es->fullscreen_output == output) {
-		if (es->width < output->width || es->height < output->height)
-			glClear(GL_COLOR_BUFFER_BIT);
-		wlsc_surface_draw(es, output, &total_damage);
+		if (es->visual == &ec->compositor.rgb_visual &&
+		    wlsc_surface_is_scanoutable(es, output)) {
+			output->scanout_surface = es;
+		} else {
+			if (es->width < output->width ||
+			    es->height < output->height)
+				glClear(GL_COLOR_BUFFER_BIT);
+			wlsc_surface_draw(es, output, &total_damage);
+		}
 	} else {
 		wl_list_for_each(es, &ec->surface_list, link) {
 			if (es->visual != &ec->compositor.rgb_visual)
diff --git a/compositor/compositor.h b/compositor/compositor.h
index e48c2b2..12905f0 100644
--- a/compositor/compositor.h
+++ b/compositor/compositor.h
@@ -51,8 +51,12 @@
 	int repaint_needed;
 	int finished;
 
+	struct wlsc_surface *scanout_surface;
+
 	int (*prepare_render)(struct wlsc_output *output);
 	int (*present)(struct wlsc_output *output);
+	int (*image_is_scanoutable)(struct wlsc_output *output,
+				    EGLImageKHR image);
 };
 
 enum wlsc_pointer_type {
@@ -157,6 +161,8 @@
 	struct wlsc_output *output;
 	enum wlsc_surface_map_type map_type;
 	struct wlsc_output *fullscreen_output;
+
+	EGLImageKHR image;
 };
 
 void