Mac Overlays: Allow multiple overlays with sandwich strategy

cc/output/overlay_strategy_common.cc

 // Copyright 2015 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_strategy_common.h"
 
 #include <limits>
 
 #include "cc/quads/io_surface_draw_quad.h"
 #include "cc/quads/solid_color_draw_quad.h"
@@ skipping 15 matching lines @@
 }
 
 bool OverlayStrategyCommon::Attempt(RenderPassList* render_passes_in_draw_order,
                                     OverlayCandidateList* candidate_list,
                                     float device_scale_factor) {
   if (!capability_checker_)
     return false;
   RenderPass* root_render_pass = render_passes_in_draw_order->back();
   DCHECK(root_render_pass);
 
+  // Add our primary surface.
+  OverlayCandidate main_image;
+  main_image.display_rect = gfx::RectF(root_render_pass->output_rect);
+  DCHECK(candidate_list->empty());
+  candidate_list->push_back(main_image);
+
+  bool created_overlay = false;
   QuadList& quad_list = root_render_pass->quad_list;
-  for (auto it = quad_list.begin(); it != quad_list.end(); ++it) {
+  for (auto it = quad_list.begin(); it != quad_list.end();) {
     OverlayCandidate candidate;
-    const DrawQuad* draw_quad = *it;
-    if (IsOverlayQuad(draw_quad) &&
-        GetCandidateQuadInfo(*draw_quad, &candidate) &&
-        delegate_->TryOverlay(capability_checker_, render_passes_in_draw_order,
-                              candidate_list, candidate, it,
-                              device_scale_factor))
-      return true;
+    if (!GetCandidateQuadInfo(**it, &candidate)) {
+      ++it;
+      continue;
+    }
+
+    OverlayResult result = delegate_->TryOverlay(
+        capability_checker_, render_passes_in_draw_order, candidate_list,
+        candidate, &it, device_scale_factor);
+    switch (result) {
+      case DID_NOT_CREATE_OVERLAY:
+        ++it;
+        break;
+      case CREATED_OVERLAY_STOP_LOOKING:
+        return true;
+      case CREATED_OVERLAY_KEEP_LOOKING:
+        created_overlay = true;
+        break;
+    }
   }
-  return false;
-}
 
-bool OverlayStrategyCommon::IsOverlayQuad(const DrawQuad* draw_quad) {
-  switch (draw_quad->material) {
-    case DrawQuad::TEXTURE_CONTENT:
-      return TextureDrawQuad::MaterialCast(draw_quad)->allow_overlay();
-    case DrawQuad::STREAM_VIDEO_CONTENT:
-      return StreamVideoDrawQuad::MaterialCast(draw_quad)->allow_overlay();
-    case DrawQuad::IO_SURFACE_CONTENT:
-      return IOSurfaceDrawQuad::MaterialCast(draw_quad)->allow_overlay;
-    default:
-      return false;
+  if (!created_overlay) {
+    DCHECK_EQ(1u, candidate_list->size());
+    candidate_list->clear();
   }
+
+  return created_overlay;
 }
 
 // static
 bool OverlayStrategyCommon::IsInvisibleQuad(const DrawQuad* draw_quad) {
   if (draw_quad->material == DrawQuad::SOLID_COLOR) {
     const SolidColorDrawQuad* solid_quad =
         SolidColorDrawQuad::MaterialCast(draw_quad);
     SkColor color = solid_quad->color;
     float opacity = solid_quad->shared_quad_state->opacity;
     float alpha = (SkColorGetA(color) * (1.0f / 255.0f)) * opacity;
     return solid_quad->ShouldDrawWithBlending() &&
            alpha < std::numeric_limits<float>::epsilon();
   }
   return false;
 }
 
 bool OverlayStrategyCommon::GetTextureQuadInfo(const TextureDrawQuad& quad,
                                                OverlayCandidate* quad_info) {
+  if (!quad.allow_overlay())
+    return false;
   gfx::OverlayTransform overlay_transform =
       OverlayCandidate::GetOverlayTransform(
           quad.shared_quad_state->quad_to_target_transform, quad.y_flipped);
   if (quad.background_color != SK_ColorTRANSPARENT ||
       quad.premultiplied_alpha ||
       overlay_transform == gfx::OVERLAY_TRANSFORM_INVALID)
     return false;
   quad_info->resource_id = quad.resource_id();
   quad_info->resource_size_in_pixels = quad.resource_size_in_pixels();
   quad_info->transform = overlay_transform;
   quad_info->uv_rect = BoundingRect(quad.uv_top_left, quad.uv_bottom_right);
   return true;
 }
 
 bool OverlayStrategyCommon::GetVideoQuadInfo(const StreamVideoDrawQuad& quad,
                                              OverlayCandidate* quad_info) {
+  if (!quad.allow_overlay())
+    return false;
   gfx::OverlayTransform overlay_transform =
       OverlayCandidate::GetOverlayTransform(
           quad.shared_quad_state->quad_to_target_transform, false);
   if (overlay_transform == gfx::OVERLAY_TRANSFORM_INVALID)
     return false;
   if (!quad.matrix.IsScaleOrTranslation()) {
     // We cannot handle anything other than scaling & translation for texture
     // coordinates yet.
     return false;
   }
@@ skipping 23 matching lines @@
   } else {
     quad_info->transform = OverlayCandidate::ModifyTransform(
         quad_info->transform, gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL);
     quad_info->uv_rect = gfx::RectF(uv0.x(), uv0.y(), delta.x(), delta.y());
   }
   return true;
 }
 
 bool OverlayStrategyCommon::GetIOSurfaceQuadInfo(const IOSurfaceDrawQuad& quad,
                                                  OverlayCandidate* quad_info) {
+  if (!quad.allow_overlay)
+    return false;
   gfx::OverlayTransform overlay_transform =
       OverlayCandidate::GetOverlayTransform(
           quad.shared_quad_state->quad_to_target_transform, false);
   if (overlay_transform != gfx::OVERLAY_TRANSFORM_NONE)
     return false;
   quad_info->resource_id = quad.io_surface_resource_id();
   quad_info->resource_size_in_pixels = quad.io_surface_size;
   quad_info->transform = overlay_transform;
   quad_info->uv_rect = gfx::RectF(1.f, 1.f);
   return true;
@@ skipping 26 matching lines @@
       return false;
   }
 
   quad_info->format = RGBA_8888;
   quad_info->display_rect = OverlayCandidate::GetOverlayRect(
       draw_quad.shared_quad_state->quad_to_target_transform, draw_quad.rect);
   return true;
 }
 
 }  // namespace cc