Split the geometry information from weston_surface out into weston_view

The weston_surface structure is split into two structures:

 * The weston_surface structure storres everything required for a
   client-side or server-side surface.  This includes buffers; callbacks;
   backend private data; input, damage, and opaque regions; and a few other
   bookkeeping bits.

 * The weston_view structure represents an entity in the scenegraph and
   storres all of the geometry information.  This includes clip region,
   alpha, position, and the transformation list as well as all of the
   temporary information derived from the geometry state.  Because a view,
   and not a surface, is a scenegraph element, the view is what is placed
   in layers and planes.

There are a few things worth noting about the surface/view split:

 1. This is *not* a modification to the protocol.  It is, instead, a
    modification to Weston's internal scenegraph to allow a single surface
    to exist in multiple places at a time.  Clients are completely unaware
    of how many views to a particular surface exist.

 2. A view is considered a direct child of a surface and is destroyed when
    the surface is destroyed.  Because of this, the view.surface pointer is
    always valid and non-null.

 3. The compositor's surface_list is replaced with a view_list.  Due to
    subsurfaces, building the view list is a little more complicated than
    it used to be and involves building a tree of views on the fly whenever
    subsurfaces are used.  However, this means that backends can remain
    completely subsurface-agnostic.

 4. Surfaces and views both keep track of which outputs they are on.

 5. The weston_surface structure now has width and height fields.  These
    are populated when a new buffer is attached before surface.configure
    is called.  This is because there are many surface-based operations
    that really require the width and height and digging through the views
    didn't work well.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
diff --git a/src/compositor-drm.c b/src/compositor-drm.c
index 60b4cba..e32e4a8 100644
--- a/src/compositor-drm.c
+++ b/src/compositor-drm.c
@@ -156,7 +156,7 @@
 	struct gbm_bo *cursor_bo[2];
 	struct weston_plane cursor_plane;
 	struct weston_plane fb_plane;
-	struct weston_surface *cursor_surface;
+	struct weston_view *cursor_view;
 	int current_cursor;
 	struct drm_fb *current, *next;
 	struct backlight *backlight;
@@ -448,23 +448,23 @@
 }
 
 static struct weston_plane *
-drm_output_prepare_scanout_surface(struct weston_output *_output,
-				   struct weston_surface *es)
+drm_output_prepare_scanout_view(struct weston_output *_output,
+				struct weston_view *ev)
 {
 	struct drm_output *output = (struct drm_output *) _output;
 	struct drm_compositor *c =
 		(struct drm_compositor *) output->base.compositor;
-	struct weston_buffer *buffer = es->buffer_ref.buffer;
+	struct weston_buffer *buffer = ev->surface->buffer_ref.buffer;
 	struct gbm_bo *bo;
 	uint32_t format;
 
-	if (es->geometry.x != output->base.x ||
-	    es->geometry.y != output->base.y ||
+	if (ev->geometry.x != output->base.x ||
+	    ev->geometry.y != output->base.y ||
 	    buffer == NULL || c->gbm == NULL ||
 	    buffer->width != output->base.current_mode->width ||
 	    buffer->height != output->base.current_mode->height ||
-	    output->base.transform != es->buffer_transform ||
-	    es->transform.enabled)
+	    output->base.transform != ev->surface->buffer_transform ||
+	    ev->transform.enabled)
 		return NULL;
 
 	bo = gbm_bo_import(c->gbm, GBM_BO_IMPORT_WL_BUFFER,
@@ -474,7 +474,7 @@
 	if (!bo)
 		return NULL;
 
-	format = drm_output_check_scanout_format(output, es, bo);
+	format = drm_output_check_scanout_format(output, ev->surface, bo);
 	if (format == 0) {
 		gbm_bo_destroy(bo);
 		return NULL;
@@ -766,7 +766,7 @@
 
 static uint32_t
 drm_output_check_sprite_format(struct drm_sprite *s,
-			       struct weston_surface *es, struct gbm_bo *bo)
+			       struct weston_view *ev, struct gbm_bo *bo)
 {
 	uint32_t i, format;
 
@@ -776,9 +776,9 @@
 		pixman_region32_t r;
 
 		pixman_region32_init_rect(&r, 0, 0,
-					  es->geometry.width,
-					  es->geometry.height);
-		pixman_region32_subtract(&r, &r, &es->opaque);
+					  ev->geometry.width,
+					  ev->geometry.height);
+		pixman_region32_subtract(&r, &r, &ev->surface->opaque);
 
 		if (!pixman_region32_not_empty(&r))
 			format = GBM_FORMAT_XRGB8888;
@@ -794,15 +794,15 @@
 }
 
 static int
-drm_surface_transform_supported(struct weston_surface *es)
+drm_view_transform_supported(struct weston_view *ev)
 {
-	return !es->transform.enabled ||
-		(es->transform.matrix.type < WESTON_MATRIX_TRANSFORM_ROTATE);
+	return !ev->transform.enabled ||
+		(ev->transform.matrix.type < WESTON_MATRIX_TRANSFORM_ROTATE);
 }
 
 static struct weston_plane *
-drm_output_prepare_overlay_surface(struct weston_output *output_base,
-				   struct weston_surface *es)
+drm_output_prepare_overlay_view(struct weston_output *output_base,
+				struct weston_view *ev)
 {
 	struct weston_compositor *ec = output_base->compositor;
 	struct drm_compositor *c =(struct drm_compositor *) ec;
@@ -817,28 +817,28 @@
 	if (c->gbm == NULL)
 		return NULL;
 
-	if (es->buffer_transform != output_base->transform)
+	if (ev->surface->buffer_transform != output_base->transform)
 		return NULL;
 
-	if (es->buffer_scale != output_base->current_scale)
+	if (ev->surface->buffer_scale != output_base->current_scale)
 		return NULL;
 
 	if (c->sprites_are_broken)
 		return NULL;
 
-	if (es->output_mask != (1u << output_base->id))
+	if (ev->output_mask != (1u << output_base->id))
 		return NULL;
 
-	if (es->buffer_ref.buffer == NULL)
+	if (ev->surface->buffer_ref.buffer == NULL)
 		return NULL;
 
-	if (es->alpha != 1.0f)
+	if (ev->alpha != 1.0f)
 		return NULL;
 
-	if (wl_shm_buffer_get(es->buffer_ref.buffer->resource))
+	if (wl_shm_buffer_get(ev->surface->buffer_ref.buffer->resource))
 		return NULL;
 
-	if (!drm_surface_transform_supported(es))
+	if (!drm_view_transform_supported(ev))
 		return NULL;
 
 	wl_list_for_each(s, &c->sprite_list, link) {
@@ -856,12 +856,12 @@
 		return NULL;
 
 	bo = gbm_bo_import(c->gbm, GBM_BO_IMPORT_WL_BUFFER,
-			   es->buffer_ref.buffer->resource,
+			   ev->surface->buffer_ref.buffer->resource,
 			   GBM_BO_USE_SCANOUT);
 	if (!bo)
 		return NULL;
 
-	format = drm_output_check_sprite_format(s, es, bo);
+	format = drm_output_check_sprite_format(s, ev, bo);
 	if (format == 0) {
 		gbm_bo_destroy(bo);
 		return NULL;
@@ -873,9 +873,9 @@
 		return NULL;
 	}
 
-	drm_fb_set_buffer(s->next, es->buffer_ref.buffer);
+	drm_fb_set_buffer(s->next, ev->surface->buffer_ref.buffer);
 
-	box = pixman_region32_extents(&es->transform.boundingbox);
+	box = pixman_region32_extents(&ev->transform.boundingbox);
 	s->plane.x = box->x1;
 	s->plane.y = box->y1;
 
@@ -885,7 +885,7 @@
 	 * for us already).
 	 */
 	pixman_region32_init(&dest_rect);
-	pixman_region32_intersect(&dest_rect, &es->transform.boundingbox,
+	pixman_region32_intersect(&dest_rect, &ev->transform.boundingbox,
 				  &output_base->region);
 	pixman_region32_translate(&dest_rect, -output_base->x, -output_base->y);
 	box = pixman_region32_extents(&dest_rect);
@@ -901,36 +901,37 @@
 	pixman_region32_fini(&dest_rect);
 
 	pixman_region32_init(&src_rect);
-	pixman_region32_intersect(&src_rect, &es->transform.boundingbox,
+	pixman_region32_intersect(&src_rect, &ev->transform.boundingbox,
 				  &output_base->region);
 	box = pixman_region32_extents(&src_rect);
 
-	weston_surface_from_global_fixed(es,
-					 wl_fixed_from_int(box->x1),
-					 wl_fixed_from_int(box->y1),
-					 &sx1, &sy1);
-	weston_surface_from_global_fixed(es,
-					 wl_fixed_from_int(box->x2),
-					 wl_fixed_from_int(box->y2),
-					 &sx2, &sy2);
+	weston_view_from_global_fixed(ev,
+				      wl_fixed_from_int(box->x1),
+				      wl_fixed_from_int(box->y1),
+				      &sx1, &sy1);
+	weston_view_from_global_fixed(ev,
+				      wl_fixed_from_int(box->x2),
+				      wl_fixed_from_int(box->y2),
+				      &sx2, &sy2);
 
 	if (sx1 < 0)
 		sx1 = 0;
 	if (sy1 < 0)
 		sy1 = 0;
-	if (sx2 > wl_fixed_from_int(es->geometry.width))
-		sx2 = wl_fixed_from_int(es->geometry.width);
-	if (sy2 > wl_fixed_from_int(es->geometry.height))
-		sy2 = wl_fixed_from_int(es->geometry.height);
+	if (sx2 > wl_fixed_from_int(ev->geometry.width))
+		sx2 = wl_fixed_from_int(ev->geometry.width);
+	if (sy2 > wl_fixed_from_int(ev->geometry.height))
+		sy2 = wl_fixed_from_int(ev->geometry.height);
 
 	tbox.x1 = sx1;
 	tbox.y1 = sy1;
 	tbox.x2 = sx2;
 	tbox.y2 = sy2;
 
-	tbox = weston_transformed_rect(wl_fixed_from_int(es->geometry.width),
-				       wl_fixed_from_int(es->geometry.height),
-				       es->buffer_transform, es->buffer_scale, tbox);
+	tbox = weston_transformed_rect(wl_fixed_from_int(ev->geometry.width),
+				       wl_fixed_from_int(ev->geometry.height),
+				       ev->surface->buffer_transform,
+				       ev->surface->buffer_scale, tbox);
 
 	s->src_x = tbox.x1 << 8;
 	s->src_y = tbox.y1 << 8;
@@ -942,8 +943,8 @@
 }
 
 static struct weston_plane *
-drm_output_prepare_cursor_surface(struct weston_output *output_base,
-				  struct weston_surface *es)
+drm_output_prepare_cursor_view(struct weston_output *output_base,
+			       struct weston_view *ev)
 {
 	struct drm_compositor *c =
 		(struct drm_compositor *) output_base->compositor;
@@ -953,18 +954,18 @@
 		return NULL;
 	if (output->base.transform != WL_OUTPUT_TRANSFORM_NORMAL)
 		return NULL;
-	if (output->cursor_surface)
+	if (output->cursor_view)
 		return NULL;
-	if (es->output_mask != (1u << output_base->id))
+	if (ev->output_mask != (1u << output_base->id))
 		return NULL;
 	if (c->cursors_are_broken)
 		return NULL;
-	if (es->buffer_ref.buffer == NULL ||
-	    !wl_shm_buffer_get(es->buffer_ref.buffer->resource) ||
-	    es->geometry.width > 64 || es->geometry.height > 64)
+	if (ev->surface->buffer_ref.buffer == NULL ||
+	    !wl_shm_buffer_get(ev->surface->buffer_ref.buffer->resource) ||
+	    ev->geometry.width > 64 || ev->geometry.height > 64)
 		return NULL;
 
-	output->cursor_surface = es;
+	output->cursor_view = ev;
 
 	return &output->cursor_plane;
 }
@@ -972,7 +973,7 @@
 static void
 drm_output_set_cursor(struct drm_output *output)
 {
-	struct weston_surface *es = output->cursor_surface;
+	struct weston_view *ev = output->cursor_view;
 	struct drm_compositor *c =
 		(struct drm_compositor *) output->base.compositor;
 	EGLint handle, stride;
@@ -981,24 +982,24 @@
 	unsigned char *s;
 	int i, x, y;
 
-	output->cursor_surface = NULL;
-	if (es == NULL) {
+	output->cursor_view = NULL;
+	if (ev == NULL) {
 		drmModeSetCursor(c->drm.fd, output->crtc_id, 0, 0, 0);
 		return;
 	}
 
-	if (es->buffer_ref.buffer &&
+	if (ev->surface->buffer_ref.buffer &&
 	    pixman_region32_not_empty(&output->cursor_plane.damage)) {
 		pixman_region32_fini(&output->cursor_plane.damage);
 		pixman_region32_init(&output->cursor_plane.damage);
 		output->current_cursor ^= 1;
 		bo = output->cursor_bo[output->current_cursor];
 		memset(buf, 0, sizeof buf);
-		stride = wl_shm_buffer_get_stride(es->buffer_ref.buffer->shm_buffer);
-		s = wl_shm_buffer_get_data(es->buffer_ref.buffer->shm_buffer);
-		for (i = 0; i < es->geometry.height; i++)
+		stride = wl_shm_buffer_get_stride(ev->surface->buffer_ref.buffer->shm_buffer);
+		s = wl_shm_buffer_get_data(ev->surface->buffer_ref.buffer->shm_buffer);
+		for (i = 0; i < ev->geometry.height; i++)
 			memcpy(buf + i * 64, s + i * stride,
-			       es->geometry.width * 4);
+			       ev->geometry.width * 4);
 
 		if (gbm_bo_write(bo, buf, sizeof buf) < 0)
 			weston_log("failed update cursor: %m\n");
@@ -1011,8 +1012,8 @@
 		}
 	}
 
-	x = (es->geometry.x - output->base.x) * output->base.current_scale;
-	y = (es->geometry.y - output->base.y) * output->base.current_scale;
+	x = (ev->geometry.x - output->base.x) * output->base.current_scale;
+	y = (ev->geometry.y - output->base.y) * output->base.current_scale;
 	if (output->cursor_plane.x != x || output->cursor_plane.y != y) {
 		if (drmModeMoveCursor(c->drm.fd, output->crtc_id, x, y)) {
 			weston_log("failed to move cursor: %m\n");
@@ -1029,7 +1030,7 @@
 {
 	struct drm_compositor *c =
 		(struct drm_compositor *) output->compositor;
-	struct weston_surface *es, *next;
+	struct weston_view *ev, *next;
 	pixman_region32_t overlap, surface_overlap;
 	struct weston_plane *primary, *next_plane;
 
@@ -1048,36 +1049,39 @@
 	 */
 	pixman_region32_init(&overlap);
 	primary = &c->base.primary_plane;
-	wl_list_for_each_safe(es, next, &c->base.surface_list, link) {
+
+	/* Flag all visible surfaces as keep_buffer = 1 */
+	wl_list_for_each(ev, &c->base.view_list, link)
+		ev->surface->keep_buffer = 1;
+
+	wl_list_for_each_safe(ev, next, &c->base.view_list, link) {
 		/* test whether this buffer can ever go into a plane:
 		 * non-shm, or small enough to be a cursor
 		 */
-		if ((es->buffer_ref.buffer &&
-		     !wl_shm_buffer_get(es->buffer_ref.buffer->resource)) ||
-		    (es->geometry.width <= 64 && es->geometry.height <= 64))
-			es->keep_buffer = 1;
-		else
-			es->keep_buffer = 0;
+		if (!ev->surface->buffer_ref.buffer ||
+		    (wl_shm_buffer_get(ev->surface->buffer_ref.buffer->resource) &&
+		    (ev->geometry.width > 64 || ev->geometry.height > 64)))
+			ev->surface->keep_buffer = 0;
 
 		pixman_region32_init(&surface_overlap);
 		pixman_region32_intersect(&surface_overlap, &overlap,
-					  &es->transform.boundingbox);
+					  &ev->transform.boundingbox);
 
 		next_plane = NULL;
 		if (pixman_region32_not_empty(&surface_overlap))
 			next_plane = primary;
 		if (next_plane == NULL)
-			next_plane = drm_output_prepare_cursor_surface(output, es);
+			next_plane = drm_output_prepare_cursor_view(output, ev);
 		if (next_plane == NULL)
-			next_plane = drm_output_prepare_scanout_surface(output, es);
+			next_plane = drm_output_prepare_scanout_view(output, ev);
 		if (next_plane == NULL)
-			next_plane = drm_output_prepare_overlay_surface(output, es);
+			next_plane = drm_output_prepare_overlay_view(output, ev);
 		if (next_plane == NULL)
 			next_plane = primary;
-		weston_surface_move_to_plane(es, next_plane);
+		weston_view_move_to_plane(ev, next_plane);
 		if (next_plane == primary)
 			pixman_region32_union(&overlap, &overlap,
-					      &es->transform.boundingbox);
+					      &ev->transform.boundingbox);
 
 		pixman_region32_fini(&surface_overlap);
 	}