Compute damage rect for Cast video compositing

cc/output/overlay_processor.cc

 // Copyright 2014 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/output/overlay_processor.h"
 
 #include "cc/output/output_surface.h"
 #include "cc/output/overlay_strategy_single_on_top.h"
 #include "cc/output/overlay_strategy_underlay.h"
 #include "cc/quads/draw_quad.h"
@@ skipping 21 matching lines @@
   cc::OverlayCandidateList* candidates_;
 
   DISALLOW_COPY_AND_ASSIGN(SendPromotionHintsBeforeReturning);
 };
 #endif
 
 }  // namespace
 
 namespace cc {
 
+bool OverlayProcessor::Strategy::GetSwapWithDamageRect(gfx::Rect* rect) {
+  return false;
+}
+
 OverlayProcessor::OverlayProcessor(OutputSurface* surface) : surface_(surface) {
 }
 
 void OverlayProcessor::Initialize() {
   DCHECK(surface_);
   OverlayCandidateValidator* validator =
       surface_->GetOverlayCandidateValidator();
   if (validator)
     validator->GetStrategies(&strategies_);
 }
@@ skipping 29 matching lines @@
   overlay_damage_rect_ = render_pass->output_rect;
   *damage_rect = gfx::Rect();
   return true;
 }
 
 void OverlayProcessor::ProcessForOverlays(ResourceProvider* resource_provider,
                                           RenderPass* render_pass,
                                           OverlayCandidateList* candidates,
                                           CALayerOverlayList* ca_layer_overlays,
                                           gfx::Rect* damage_rect) {
+  have_swap_with_damage_rect_ = false;
 #if defined(OS_ANDROID)
   // Be sure to send out notifications, regardless of whether we get to
   // processing for overlays or not.  If we don't, then we should notify that
   // they are not promotable.
   SendPromotionHintsBeforeReturning notifier(resource_provider, candidates);
 #endif
 
   // If we have any copy requests, we can't remove any quads for overlays or
   // CALayers because the framebuffer would be missing the removed quads'
   // contents.
   if (!render_pass->copy_requests.empty()) {
     // If overlay processing was skipped for a frame there's no way to be sure
     // of the state of the previous frame, so reset.
     previous_frame_underlay_rect_ = gfx::Rect();
     return;
   }
 
   // First attempt to process for CALayers.
   if (ProcessForCALayers(resource_provider, render_pass, candidates,
                          ca_layer_overlays, damage_rect)) {
     return;
   }
 
   // Only if that fails, attempt hardware overlay strategies.
   for (const auto& strategy : strategies_) {
     if (!strategy->Attempt(resource_provider, render_pass, candidates))
       continue;
 
+    have_swap_with_damage_rect_ =
+        strategy->GetSwapWithDamageRect(&swap_with_damage_rect_);
+
     UpdateDamageRect(candidates, damage_rect);
     return;
   }
 }
 
+bool OverlayProcessor::GetSwapWithDamageRect(gfx::Rect* damage_rect) {
+  DCHECK(damage_rect);
+  *damage_rect = swap_with_damage_rect_;
+  return have_swap_with_damage_rect_;
+}
+
 // Subtract on-top overlays from the damage rect, unless the overlays use
 // the backbuffer as their content (in which case, add their combined rect
 // back to the damage at the end).
 // Also subtract unoccluded underlays from the damage rect if we know that the
 // same underlay was scheduled on the previous frame. If the renderer decides
 // not to swap the framebuffer there will still be a transparent hole in the
 // previous frame. This only handles the common case of a single underlay quad
 // for fullscreen video.
 void OverlayProcessor::UpdateDamageRect(OverlayCandidateList* candidates,
                                         gfx::Rect* damage_rect) {
@@ skipping 14 matching lines @@
   }
 
   if (this_frame_underlay_rect == previous_frame_underlay_rect_)
     damage_rect->Subtract(this_frame_underlay_rect);
   previous_frame_underlay_rect_ = this_frame_underlay_rect;
 
   damage_rect->Union(output_surface_overlay_damage_rect);
 }
 
 }  // namespace cc