cc/output/overlay_strategy_single_on_top.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "cc/output/overlay_strategy_single_on_top.h"
   6
   7 #include <limits>
   8
   9 #include "cc/quads/draw_quad.h"
  10
  11 namespace cc {
  12
  13 OverlayStrategySingleOnTop::OverlayStrategySingleOnTop(
  14     OverlayCandidateValidator* capability_checker,
  15     ResourceProvider* resource_provider)
  16     : OverlayStrategyCommon(capability_checker, resource_provider) {
  17 }
  18
  19 bool OverlayStrategySingleOnTop::Attempt(
  20     RenderPassList* render_passes_in_draw_order,
  21     OverlayCandidateList* candidate_list) {
  22   // Only attempt to handle very simple case for now.
  23   if (!capability_checker_)
  24     return false;
  25
  26   RenderPass* root_render_pass = render_passes_in_draw_order->back();
  27   DCHECK(root_render_pass);
  28
  29   OverlayCandidate candidate;
  30   QuadList& quad_list = root_render_pass->quad_list;
  31   auto candidate_iterator = quad_list.end();
  32   for (auto it = quad_list.begin(); it != quad_list.end(); ++it) {
  33     const DrawQuad* draw_quad = *it;
  34     if (IsOverlayQuad(draw_quad)) {
  35       // Check that no prior quads overlap it.
  36       bool intersects = false;
  37       gfx::RectF rect = draw_quad->rect;
  38       draw_quad->quadTransform().TransformRect(&rect);
  39       for (auto overlap_iter = quad_list.cbegin(); overlap_iter != it;
  40            ++overlap_iter) {
  41         gfx::RectF overlap_rect = overlap_iter->rect;
  42         overlap_iter->quadTransform().TransformRect(&overlap_rect);
  43         if (rect.Intersects(overlap_rect) && !IsInvisibleQuad(*overlap_iter)) {
  44           intersects = true;
  45           break;
  46         }
  47       }
  48       if (intersects || !GetCandidateQuadInfo(*draw_quad, &candidate))
  49         continue;
  50       candidate_iterator = it;
  51       break;
  52     }
  53   }
  54   if (candidate_iterator == quad_list.end())
  55     return false;
  56
  57   // Add our primary surface.
  58   OverlayCandidateList candidates;
  59   OverlayCandidate main_image;
  60   main_image.display_rect = root_render_pass->output_rect;
  61   candidates.push_back(main_image);
  62
  63   // Add the overlay.
  64   candidate.plane_z_order = 1;
  65   candidates.push_back(candidate);
  66
  67   // Check for support.
  68   capability_checker_->CheckOverlaySupport(&candidates);
  69
  70   // If the candidate can be handled by an overlay, create a pass for it.
  71   if (candidates[1].overlay_handled) {
  72     quad_list.EraseAndInvalidateAllPointers(candidate_iterator);
  73     candidate_list->swap(candidates);
  74     return true;
  75   }
  76   return false;
  77 }
  78
  79 }  // namespace cc