Split picture layer quads to allow removing more occluded area.

cc/layers/picture_layer_impl.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layers/picture_layer_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 344 matching lines @@
           // trying to produce, even though it may not be ideal. Since that's
           // the best the layer can promise in the future, consider those as
           // complete. But if a tile is ideal scale, we don't want to consider
           // it incomplete and trying to replace it with a tile at a worse
           // scale.
           if (iter->contents_scale_key() != raster_contents_scale_ &&
               iter->contents_scale_key() != ideal_contents_scale_ &&
               geometry_rect.Intersects(scaled_viewport_for_tile_priority)) {
             append_quads_data->num_incomplete_tiles++;
           }
-
-          TileDrawQuad* quad =
-              render_pass->CreateAndAppendDrawQuad<TileDrawQuad>();
-          quad->SetNew(shared_quad_state, geometry_rect, opaque_rect,
-                       visible_geometry_rect, draw_info.resource_id(),
-                       texture_rect, draw_info.resource_size(),
-                       draw_info.contents_swizzled(), nearest_neighbor_);
-          ValidateQuadResources(quad);
+          Region unoccluded_region(visible_geometry_rect);
+          scaled_occlusion.OccludeContentRegion(&unoccluded_region);
+          for (Region::Iterator iterator(unoccluded_region);
+               iterator.has_rect(); iterator.next()) {
+            TileDrawQuad* quad =
+                render_pass->CreateAndAppendDrawQuad<TileDrawQuad>();
+            quad->SetNew(shared_quad_state, geometry_rect, opaque_rect,
+                         iterator.rect(), draw_info.resource_id(), texture_rect,
+                         draw_info.resource_size(),
+                         draw_info.contents_swizzled(), nearest_neighbor_);
+            ValidateQuadResources(quad);
+          }
           has_draw_quad = true;
           break;
         }
         case TileDrawInfo::SOLID_COLOR_MODE: {
           float alpha =
               (SkColorGetA(draw_info.solid_color()) * (1.0f / 255.0f)) *
               shared_quad_state->opacity;
           if (mask_type_ == Layer::LayerMaskType::MULTI_TEXTURE_MASK ||
               alpha >= std::numeric_limits<float>::epsilon()) {
-            SolidColorDrawQuad* quad =
-                render_pass->CreateAndAppendDrawQuad<SolidColorDrawQuad>();
-            quad->SetNew(shared_quad_state, geometry_rect,
-                         visible_geometry_rect, draw_info.solid_color(), false);
-            ValidateQuadResources(quad);
+            Region unoccluded_region(visible_geometry_rect);
+            scaled_occlusion.OccludeContentRegion(&unoccluded_region);
+            for (Region::Iterator iterator(unoccluded_region);
+                 iterator.has_rect(); iterator.next()) {
+              SolidColorDrawQuad* quad =
+                  render_pass->CreateAndAppendDrawQuad<SolidColorDrawQuad>();
+              quad->SetNew(shared_quad_state, geometry_rect, iterator.rect(),
+                           draw_info.solid_color(), false);
+              ValidateQuadResources(quad);
+            }
           }
           has_draw_quad = true;
           break;
         }
         case TileDrawInfo::OOM_MODE:
           break;  // Checkerboard.
       }
     }
 
     if (!has_draw_quad) {
@@ skipping 1086 matching lines @@
   }
 
   invalidation_.Union(invalidation);
   tilings_->UpdateTilingsForImplSideInvalidation(invalidation);
   SetNeedsPushProperties();
   TRACE_EVENT_END1("cc", "PictureLayerImpl::InvalidateRegionForImages",
                    "Invalidation", invalidation.ToString());
 }
 
 }  // namespace cc