src/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 "cc/quads/draw_quad.h"
   8 #include "cc/quads/texture_draw_quad.h"
   9 #include "ui/gfx/geometry/rect_conversions.h"
  10 #include "ui/gfx/transform.h"
  11
  12 namespace cc {
  13
  14 OverlayStrategySingleOnTop::OverlayStrategySingleOnTop(
  15     OverlayCandidateValidator* capability_checker,
  16     ResourceProvider* resource_provider)
  17     : capability_checker_(capability_checker),
  18       resource_provider_(resource_provider) {}
  19
  20 bool OverlayStrategySingleOnTop::Attempt(
  21     RenderPassList* render_passes_in_draw_order,
  22     OverlayCandidateList* candidate_list) {
  23   // Only attempt to handle very simple case for now.
  24   if (!capability_checker_)
  25     return false;
  26
  27   RenderPass* root_render_pass = render_passes_in_draw_order->back();
  28   DCHECK(root_render_pass);
  29
  30   QuadList& quad_list = root_render_pass->quad_list;
  31   QuadList::Iterator candidate_iterator = quad_list.end();
  32   for (QuadList::Iterator it = quad_list.begin(); it != quad_list.end(); ++it) {
  33     const DrawQuad* draw_quad = &*it;
  34     if (draw_quad->material == DrawQuad::TEXTURE_CONTENT) {
  35       const TextureDrawQuad& quad = *TextureDrawQuad::MaterialCast(draw_quad);
  36       if (!resource_provider_->AllowOverlay(quad.resource_id)) {
  37         continue;
  38       }
  39       // Check that no prior quads overlap it.
  40       bool intersects = false;
  41       gfx::RectF rect = draw_quad->rect;
  42       draw_quad->quadTransform().TransformRect(&rect);
  43       for (QuadList::Iterator overlap_iter = quad_list.begin();
  44            overlap_iter != it;
  45            ++overlap_iter) {
  46         gfx::RectF overlap_rect = overlap_iter->rect;
  47         overlap_iter->quadTransform().TransformRect(&overlap_rect);
  48         if (rect.Intersects(overlap_rect)) {
  49           intersects = true;
  50           break;
  51         }
  52       }
  53       if (intersects)
  54         continue;
  55       candidate_iterator = it;
  56       break;
  57     }
  58   }
  59   if (candidate_iterator == quad_list.end())
  60     return false;
  61   const TextureDrawQuad& quad =
  62       *TextureDrawQuad::MaterialCast(&*candidate_iterator);
  63
  64   // Simple quads only.
  65   gfx::OverlayTransform overlay_transform =
  66       OverlayCandidate::GetOverlayTransform(quad.quadTransform(), quad.flipped);
  67   if (overlay_transform == gfx::OVERLAY_TRANSFORM_INVALID ||
  68       !quad.quadTransform().IsIdentityOrTranslation() || quad.needs_blending ||
  69       quad.shared_quad_state->opacity != 1.f ||
  70       quad.shared_quad_state->blend_mode != SkXfermode::kSrcOver_Mode ||
  71       quad.premultiplied_alpha || quad.background_color != SK_ColorTRANSPARENT)
  72     return false;
  73
  74   // Add our primary surface.
  75   OverlayCandidateList candidates;
  76   OverlayCandidate main_image;
  77   main_image.display_rect = root_render_pass->output_rect;
  78   main_image.format = RGBA_8888;
  79   candidates.push_back(main_image);
  80
  81   // Add the overlay.
  82   OverlayCandidate candidate;
  83   candidate.transform = overlay_transform;
  84   candidate.display_rect =
  85       OverlayCandidate::GetOverlayRect(quad.quadTransform(), quad.rect);
  86   candidate.uv_rect = BoundingRect(quad.uv_top_left, quad.uv_bottom_right);
  87   candidate.format = RGBA_8888;
  88   candidate.resource_id = quad.resource_id;
  89   candidate.plane_z_order = 1;
  90   candidates.push_back(candidate);
  91
  92   // Check for support.
  93   capability_checker_->CheckOverlaySupport(&candidates);
  94
  95   // If the candidate can be handled by an overlay, create a pass for it.
  96   if (candidates[1].overlay_handled) {
  97     quad_list.EraseAndInvalidateAllPointers(candidate_iterator);
  98     candidate_list->swap(candidates);
  99     return true;
 100   }
 101   return false;
 102 }
 103
 104 }  // namespace cc