cc: Resource list for headup display

cc/layers/heads_up_display_layer_impl.cc

Index: cc/layers/heads_up_display_layer_impl.cc
diff --git a/cc/layers/heads_up_display_layer_impl.cc b/cc/layers/heads_up_display_layer_impl.cc
index fcb2733aee90279959fff97e43148cba86413eb4..1f926ee446e9de31c20433a2801897f38d3872ab 100644
--- a/cc/layers/heads_up_display_layer_impl.cc
+++ b/cc/layers/heads_up_display_layer_impl.cc
@@ -50,6 +50,18 @@ static inline SkPaint CreatePaint() {
   return paint;
 }
 
+class CompareResourceSize {

[danakj, 2014/08/29 16:42:46]

move this down above the function that uses it

+ public:
+  explicit CompareResourceSize(gfx::Size size_) : compare_size_(size_) {}

[danakj, 2014/08/29 16:42:47]

const gfx::Size&

+
+  bool operator()(const ScopedResource* resource) {
+    return (resource->size() == compare_size_);

[danakj, 2014/08/29 16:42:47]

drop the extra ()s

+  }
+
+ private:
+  const gfx::Size compare_size_;
+};
+
 HeadsUpDisplayLayerImpl::Graph::Graph(double indicator_value,
                                       double start_upper_bound)
     : value(0.0),
@@ -81,27 +93,46 @@ scoped_ptr<LayerImpl> HeadsUpDisplayLayerImpl::CreateLayerImpl(
   return HeadsUpDisplayLayerImpl::Create(tree_impl, id()).PassAs<LayerImpl>();
 }
 
-bool HeadsUpDisplayLayerImpl::WillDraw(DrawMode draw_mode,
-                                       ResourceProvider* resource_provider) {
-  if (draw_mode == DRAW_MODE_RESOURCELESS_SOFTWARE)
-    return false;
+void HeadsUpDisplayLayerImpl::AcquireResource(
+    ResourceProvider* resource_provider) {
+  for (ScopedPtrVector<ScopedResource>::iterator it = resources_.begin();
+       it != resources_.end();
+       ++it) {
+    if (!resource_provider->InUseByConsumer((*it)->id())) {
+      resources_.swap(it, resources_.end() - 1);
+      return;
+    }
+  }
 
-  if (!hud_resource_)
-    hud_resource_ = ScopedResource::Create(resource_provider);
+  scoped_ptr<ScopedResource> resource =
+      ScopedResource::Create(resource_provider);
+  resource->Allocate(
+      content_bounds(), ResourceProvider::TextureHintImmutable, RGBA_8888);
+  resources_.push_back(resource.Pass());
+}
 
-  // TODO(danakj): The HUD could swap between two textures instead of creating a
-  // texture every frame in ubercompositor.
-  if (hud_resource_->size() != content_bounds() ||
-      (hud_resource_->id() &&
-       resource_provider->InUseByConsumer(hud_resource_->id()))) {
-    hud_resource_->Free();
+void HeadsUpDisplayLayerImpl::ReleaseUnmatchedSizeResources(
+    ResourceProvider* resource_provider) {
+  ScopedPtrVector<ScopedResource>::iterator it_erase = resources_.end();
+  for (ScopedPtrVector<ScopedResource>::iterator it = resources_.begin();
+       it != resources_.end();
+       ++it) {
+    if ((*it)->size() != content_bounds()) {
+      it_erase = resources_.partition(CompareResourceSize(content_bounds()));

[danakj, 2014/08/29 16:42:47]

if you wanna use partition, why do the for loop around it? Just call partition
and done?

+      break;
+    }
   }
+  if (it_erase != resources_.end())

[danakj, 2014/08/29 16:42:46]

drop the if, just erase.

+    resources_.erase(it_erase, resources_.end());
+}
 
-  if (!hud_resource_->id()) {
-    hud_resource_->Allocate(
-        content_bounds(), ResourceProvider::TextureHintImmutable, RGBA_8888);
-  }
+bool HeadsUpDisplayLayerImpl::WillDraw(DrawMode draw_mode,
+                                       ResourceProvider* resource_provider) {
+  if (draw_mode == DRAW_MODE_RESOURCELESS_SOFTWARE)
+    return false;
 
+  ReleaseUnmatchedSizeResources(resource_provider);
+  AcquireResource(resource_provider);
   return LayerImpl::WillDraw(draw_mode, resource_provider);
 }
 
@@ -109,7 +140,7 @@ void HeadsUpDisplayLayerImpl::AppendQuads(
     RenderPass* render_pass,
     const OcclusionTracker<LayerImpl>& occlusion_tracker,
     AppendQuadsData* append_quads_data) {
-  if (!hud_resource_->id())
+  if (!resources_.back()->id())
     return;
 
   SharedQuadState* shared_quad_state =
@@ -130,7 +161,7 @@ void HeadsUpDisplayLayerImpl::AppendQuads(
                quad_rect,
                opaque_rect,
                visible_quad_rect,
-               hud_resource_->id(),
+               resources_.back()->id(),
                premultiplied_alpha,
                uv_top_left,
                uv_bottom_right,
@@ -142,7 +173,7 @@ void HeadsUpDisplayLayerImpl::AppendQuads(
 void HeadsUpDisplayLayerImpl::UpdateHudTexture(
     DrawMode draw_mode,
     ResourceProvider* resource_provider) {
-  if (draw_mode == DRAW_MODE_RESOURCELESS_SOFTWARE || !hud_resource_->id())
+  if (draw_mode == DRAW_MODE_RESOURCELESS_SOFTWARE || !resources_.back()->id())
     return;
 
   SkISize canvas_size;
@@ -179,14 +210,16 @@ void HeadsUpDisplayLayerImpl::UpdateHudTexture(
   DCHECK(pixels);
   gfx::Rect content_rect(content_bounds());
   DCHECK(info.colorType() == kN32_SkColorType);
-  resource_provider->SetPixels(hud_resource_->id(),
+  resource_provider->SetPixels(resources_.back()->id(),
                                static_cast<const uint8_t*>(pixels),
                                content_rect,
                                content_rect,
                                gfx::Vector2d());
 }
 
-void HeadsUpDisplayLayerImpl::ReleaseResources() { hud_resource_.reset(); }
+void HeadsUpDisplayLayerImpl::ReleaseResources() {
+  resources_.clear();
+}
 
 void HeadsUpDisplayLayerImpl::UpdateHudContents() {
   const LayerTreeDebugState& debug_state = layer_tree_impl()->debug_state();