Splitting of layers for correct intersections

Sorting 3d-sorted layers and rendering them in that order causes issues
when layers intersect. Instead place 3d-sorted layers in a bsp tree and
fragment any intersecting layers into non-rectangular quads. We can then
render the fragments in the correct sorted order regardless of
intersections.

BUG=455918,159225,132122,230833

Review URL: https://codereview.chromium.org/595593002

Cr-Commit-Position: refs/heads/master@{#320276}

1 files changed, 16 insertions, 0 deletions

diff --git a/cc/output/bsp_walk_action.h b/cc/output/bsp_walk_action.h
index ac8fa41..a89d8ea 100644
--- a/cc/output/bsp_walk_action.h
+++ b/cc/output/bsp_walk_action.h
@@ -20,6 +20,22 @@ class CC_EXPORT BspWalkAction {
 
 // The BspTree class takes ownership of all the DrawPolygons returned in list_
 // so the BspTree must be preserved while elements in that vector are in use.
+class CC_EXPORT BspWalkActionDrawPolygon : public BspWalkAction {
+ public:
+  void operator()(DrawPolygon* item) override;
+
+  BspWalkActionDrawPolygon(DirectRenderer* renderer,
+                           DirectRenderer::DrawingFrame* frame,
+                           const gfx::Rect& render_pass_scissor,
+                           bool using_scissor_as_optimization);
+
+ private:
+  DirectRenderer* renderer_;
+  DirectRenderer::DrawingFrame* frame_;
+  const gfx::Rect& render_pass_scissor_;
+  bool using_scissor_as_optimization_;
+};
+
 class CC_EXPORT BspWalkActionToVector : public BspWalkAction {
  public:
   explicit BspWalkActionToVector(std::vector<DrawPolygon*>* in_list);