Auto merge of #3302 - gw3583:pic-state, r=kvark

Remove local_rect_changed from PictureState.

This can now be handled internally, and removes one more need
for the PictureState structure during the main traversal.

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webrender/src/frame_builder.rs

@@ -106,7 +106,6 @@ pub struct PictureContext {
 /// the children are processed.
 pub struct PictureState {
     pub is_cacheable: bool,
-    pub local_rect_changed: bool,
     pub map_local_to_pic: SpaceMapper<LayoutPixel, PicturePixel>,
     pub map_pic_to_world: SpaceMapper<PicturePixel, WorldPixel>,
     pub map_pic_to_raster: SpaceMapper<PicturePixel, RasterPixel>,

webrender/src/picture.rs

@@ -559,7 +559,6 @@ impl PicturePrimitive {
 
         let state = PictureState {
             is_cacheable: true,
-            local_rect_changed: false,
             map_local_to_pic,
             map_pic_to_world,
             map_pic_to_raster,
@@ -607,25 +606,35 @@ impl PicturePrimitive {
         context: PictureContext,
         state: PictureState,
         frame_state: &mut FrameBuildingState,
-    ) -> (bool, Option<ClipNodeCollector>) {
+    ) -> Option<ClipNodeCollector> {
         self.prim_list = prim_list;
         self.state = Some((state, context));
 
         match self.raster_config {
             Some(ref raster_config) => {
                 let local_rect = frame_state.surfaces[raster_config.surface_index.0].rect;
                 let local_rect = LayoutRect::from_untyped(&local_rect.to_untyped());
-                let local_rect_changed = local_rect != self.local_rect;
-                self.local_rect = local_rect;
 
-                if local_rect_changed {
-                    frame_state.gpu_cache.invalidate(&mut self.gpu_location);
+                // If the local rect changed (due to transforms in child primitives) then
+                // invalidate the GPU cache location to re-upload the new local rect
+                // and stretch size. Drop shadow filters also depend on the local rect
+                // size for the extra GPU cache data handle.
+                // TODO(gw): In future, if we support specifying a flag which gets the
+                //           stretch size from the segment rect in the shaders, we can
+                //           remove this invalidation here completely.
+                if self.local_rect != local_rect {
+                    frame_state.gpu_cache.invalidate(&self.gpu_location);
+                    if let PictureCompositeMode::Filter(FilterOp::DropShadow(..)) = raster_config.composite_mode {
+                        frame_state.gpu_cache.invalidate(&self.extra_gpu_data_handle);
+                    }
                 }
 
-                (local_rect_changed, Some(frame_state.clip_store.pop_surface()))
+                self.local_rect = local_rect;
+
+                Some(frame_state.clip_store.pop_surface())
             }
             None => {
-                (false, None)
+                None
             }
         }
     }
@@ -957,7 +966,6 @@ impl PicturePrimitive {
         prim_instance: &PrimitiveInstance,
         prim_local_rect: &LayoutRect,
         surface_index: SurfaceIndex,
-        pic_state: &mut PictureState,
         frame_context: &FrameBuildingContext,
         frame_state: &mut FrameBuildingState,
     ) -> bool {
@@ -1198,14 +1206,6 @@ impl PicturePrimitive {
                 let render_task_id = frame_state.render_tasks.add(blur_render_task);
                 surfaces[surface_index.0].tasks.push(render_task_id);
 
-                // If the local rect of the contents changed, force the cache handle
-                // to be invalidated so that the primitive data below will get
-                // uploaded to the GPU this frame. This can occur during property
-                // animation.
-                if pic_state.local_rect_changed {
-                    frame_state.gpu_cache.invalidate(&mut self.extra_gpu_data_handle);
-                }
-
                 if let Some(mut request) = frame_state.gpu_cache.request(&mut self.extra_gpu_data_handle) {
                     // TODO(gw): This is very hacky code below! It stores an extra
                     //           brush primitive below for the special case of a

webrender/src/prim_store.rs

@@ -2200,7 +2200,7 @@ impl PrimitiveStore {
                 }
 
                 // Restore the dependencies (borrow check dance)
-                let (local_rect_changed, clip_node_collector) = self
+                let clip_node_collector = self
                     .pictures[pic_context_for_children.pic_index.0]
                     .restore_context(
                         prim_list,
@@ -2209,8 +2209,6 @@ impl PrimitiveStore {
                         frame_state,
                     );
 
-                pic_state.local_rect_changed |= local_rect_changed;
-
                 (is_passthrough, clip_node_collector)
             }
             None => {
@@ -2364,7 +2362,6 @@ impl PrimitiveStore {
                     prim_instance,
                     &prim_local_rect,
                     pic_context.surface_index,
-                    pic_state,
                     frame_context,
                     frame_state,
                 ) {