Bug 1757201 - Fix mix-blend mode on parent surfaces with snapping ena…

…bled r=gfx-reviewers,lsalzman Differential Revision: https://phabricator.services.mozilla.com/D139904 [ghsync] From https://hg.mozilla.org/mozilla-central/rev/7aaefe97188d8b0f65da8e52980de830761a8153
EllisonZhang · Mar 2, 2022 · 216acba · 216acba
1 parent 4fe3556
commit 216acba
Show file tree

Hide file tree

Showing 4 changed files with 142 additions and 9 deletions.
diff --git a/webrender/src/picture.rs b/webrender/src/picture.rs
@@ -3761,6 +3761,29 @@ impl SurfaceInfo {
         }
     }
 
+    pub fn map_to_device_rect(
+        &self,
+        local_rect: &PictureRect,
+        spatial_tree: &SpatialTree,
+    ) -> DeviceRect {
+        let raster_rect = if self.raster_spatial_node_index != self.surface_spatial_node_index {
+            assert_eq!(self.device_pixel_scale.0, 1.0);
+
+            let local_to_world = SpaceMapper::new_with_target(
+                spatial_tree.root_reference_frame_index(),
+                self.surface_spatial_node_index,
+                WorldRect::max_rect(),
+                spatial_tree,
+            );
+
+            local_to_world.map(&local_rect).unwrap()
+        } else {
+            local_rect.cast_unit()
+        };
+
+        raster_rect * self.device_pixel_scale
+    }
+
     /// Clip and transform a local rect to a device rect suitable for allocating
     /// a child off-screen surface of this surface (e.g. for clip-masks)
     pub fn get_surface_rect(
@@ -5051,20 +5074,17 @@ impl PicturePrimitive {
                         frame_context.fb_config.dual_source_blending_is_enabled &&
                             frame_context.fb_config.dual_source_blending_is_supported,
                     ).is_none() => {
-
                         let parent_surface = &frame_state.surfaces[parent_surface_index.0];
-                        let parent_raster_spatial_node_index = parent_surface.raster_spatial_node_index;
-                        let parent_device_pixel_scale = parent_surface.device_pixel_scale;
 
                         // Create a space mapper that will allow mapping from the local rect
                         // of the mix-blend primitive into the space of the surface that we
                         // need to read back from. Note that we use the parent's raster spatial
                         // node here, so that we are in the correct device space of the parent
                         // surface, whether it establishes a raster root or not.
                         let map_pic_to_parent = SpaceMapper::new_with_target(
-                            parent_raster_spatial_node_index,
-                            self.spatial_node_index,
-                            RasterRect::max_rect(),         // TODO(gw): May need a conservative estimate?
+                            parent_surface.surface_spatial_node_index,
+                            surface_spatial_node_index,
+                            parent_surface.clipping_rect,
                             frame_context.spatial_tree,
                         );
                         let pic_in_raster_space = map_pic_to_parent
@@ -5073,8 +5093,8 @@ impl PicturePrimitive {
 
                         // Apply device pixel ratio for parent surface to get into device
                         // pixels for that surface.
-                        let backdrop_rect = pic_in_raster_space.cast_unit() * parent_device_pixel_scale;
-                        let parent_surface_rect = parent_surface.clipping_rect.cast_unit() * parent_device_pixel_scale;
+                        let backdrop_rect = pic_in_raster_space;
+                        let parent_surface_rect = parent_surface.clipping_rect;
 
                         // If there is no available parent surface to read back from (for example, if
                         // the parent surface is affected by a clip that doesn't affect the child
@@ -5088,7 +5108,16 @@ impl PicturePrimitive {
                                 // from the primitive rect within the readback region. This is
                                 // 0..1 for aligned surfaces, but doing it this way allows
                                 // accurate sampling if the primitive bounds have fractional values.
-                                let available_rect = available_rect.round_out();
+
+                                let backdrop_rect = parent_surface.map_to_device_rect(
+                                    &backdrop_rect,
+                                    frame_context.spatial_tree,
+                                );
+
+                                let available_rect = parent_surface.map_to_device_rect(
+                                    &available_rect,
+                                    frame_context.spatial_tree,
+                                ).round_out();
 
                                 let backdrop_uv = calculate_uv_rect_kind(
                                     available_rect,

diff --git a/wrench/reftests/text/mix-blend-layers-ref.yaml b/wrench/reftests/text/mix-blend-layers-ref.yaml
@@ -0,0 +1,50 @@
+---
+root:
+  items:
+    - type: stacking-context
+      bounds: [100, 100, 0, 0]
+      blend-container: true
+      items:
+        - type: "shadow"
+          blur-radius: 0
+          offset: [-10, -4]
+          color: [255, 255, 0, 1]
+        - text: "Fault"
+          origin: 200 300
+          size: 200
+          color: [0, 0, 0, 0]
+          font: "VeraBd.ttf"
+        -
+          type: "pop-all-shadows"
+
+        - type: stacking-context
+          blend-container: true
+          mix-blend-mode: darken
+          items:
+            - type: "shadow"
+              blur-radius: 0
+              offset: [6, -8]
+              color: [0, 255, 255, 1]
+            - text: "Fault"
+              origin: 200 300
+              size: 200
+              color: [0, 0, 0, 0]
+              font: "VeraBd.ttf"
+            -
+              type: "pop-all-shadows"
+
+            - type: stacking-context
+              blend-container: true
+              mix-blend-mode: darken
+              items:
+                - type: "shadow"
+                  blur-radius: 0
+                  offset: [10, 4]
+                  color: [255, 0, 255, 1]
+                - text: "Fault"
+                  origin: 200 300
+                  size: 200
+                  color: [0, 0, 0, 0]
+                  font: "VeraBd.ttf"
+                -
+                  type: "pop-all-shadows"
diff --git a/wrench/reftests/text/mix-blend-layers.yaml b/wrench/reftests/text/mix-blend-layers.yaml
@@ -0,0 +1,53 @@
+# Verify that surfaces with differing surface/raster spatial nodes correctly sample from
+# parent mix-blend container surfaces
+---
+root:
+  items:
+    - type: stacking-context
+      bounds: [100, 100, 0, 0]
+      transform: scale(2)
+      blend-container: true
+      items:
+        - type: "shadow"
+          blur-radius: 0
+          offset: [-5, -2]
+          color: [255, 255, 0, 1]
+        - text: "Fault"
+          origin: 100 150
+          size: 100
+          color: [0, 0, 0, 0]
+          font: "VeraBd.ttf"
+        -
+          type: "pop-all-shadows"
+
+        - type: stacking-context
+          blend-container: true
+          mix-blend-mode: darken
+          items:
+            - type: "shadow"
+              blur-radius: 0
+              offset: [3, -4]
+              color: [0, 255, 255, 1]
+            - text: "Fault"
+              origin: 100 150
+              size: 100
+              color: [0, 0, 0, 0]
+              font: "VeraBd.ttf"
+            -
+              type: "pop-all-shadows"
+
+            - type: stacking-context
+              blend-container: true
+              mix-blend-mode: darken
+              items:
+                - type: "shadow"
+                  blur-radius: 0
+                  offset: [5, 2]
+                  color: [255, 0, 255, 1]
+                - text: "Fault"
+                  origin: 100 150
+                  size: 100
+                  color: [0, 0, 0, 0]
+                  font: "VeraBd.ttf"
+                -
+                  type: "pop-all-shadows"
diff --git a/wrench/reftests/text/reftest.list b/wrench/reftests/text/reftest.list
@@ -85,3 +85,4 @@ skip_on(android) fuzzy(220,7600) == raster_root_C_8192.yaml raster_root_C_ref.ya
 == subpx-bg-mask.yaml subpx-bg-mask-ref.yaml
 platform(linux,mac) == rotate-snap-clip.yaml rotate-snap-clip-ref.yaml
 platform(linux,mac) == rotate-snap-filter.yaml rotate-snap-filter-ref.yaml
+== mix-blend-layers.yaml mix-blend-layers-ref.yaml