Start of hardware overlay support in CC with Ubercompositor.

cc/quads/render_pass.h

 // Copyright 2011 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.
 
 #ifndef CC_QUADS_RENDER_PASS_H_
 #define CC_QUADS_RENDER_PASS_H_
 
 #include <utility>
 
 #include "base/basictypes.h"
@@ skipping 44 matching lines @@
     }
     bool operator!=(const Id& other) const {
       return !(*this == other);
     }
     bool operator<(const Id& other) const {
       return layer_id < other.layer_id ||
           (layer_id == other.layer_id && index < other.index);
     }
   };
 
+  enum HwOverlayState { NO_OVERLAY, RENDER_AND_OVERLAY, SIMPLE_OVERLAY, };

[enne (OOO), 2014/03/14 18:13:41]

bikeshed: maybe just OverlayState? Are there other kinds of overlays?

+
   ~RenderPass();
 
   static scoped_ptr<RenderPass> Create();
   static scoped_ptr<RenderPass> Create(size_t num_layers);
 
   // A shallow copy of the render pass, which does not include its quads or copy
   // requests.
   scoped_ptr<RenderPass> Copy(Id new_id) const;
 
   // A deep copy of the render passes in the list including the quads.
@@ skipping 29 matching lines @@
 
   // If non-empty, the renderer should produce a copy of the render pass'
   // contents as a bitmap, and give a copy of the bitmap to each callback in
   // this list. This property should not be serialized between compositors, as
   // it only makes sense in the root compositor.
   ScopedPtrVector<CopyOutputRequest> copy_requests;
 
   QuadList quad_list;
   SharedQuadStateList shared_quad_state_list;
 
+  // Specifies whether the pass is going into an overlay, needs to be rendered
+  // into a buffer before it can be presented to overlay hardware or a quad
+  // inside it is presented as is.

[piman, 2014/03/14 03:42:34]

nit: this would be a great comment to have on the enum rather than here.

+  HwOverlayState overlay_state;

[piman, 2014/03/14 03:42:34]

Generally, adding a field here requires it to be added to
ParamTraits<cc::RenderPass> in cc_messages.cc (and also to corresponding tests).

That said, in this case I'm not sure we'd ever want to IPC the value of this
field. If not indeed, we should simply add a DCHECK in
ParamTraits<cc::RenderPass>::Write that it's the default value.

[alexst (slow to review), 2014/03/14 19:54:22]

Yes, this should only exist in one process. I added a DCHECK, thank you for
noting that.

+
  protected:
   explicit RenderPass(size_t num_layers);
   RenderPass();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(RenderPass);
 };
 
 }  // namespace cc
 
@@ skipping 13 matching lines @@
 #error define a hash function for your compiler
 #endif  // COMPILER
 }  // namespace BASE_HASH_NAMESPACE
 
 namespace cc {
 typedef ScopedPtrVector<RenderPass> RenderPassList;
 typedef base::hash_map<RenderPass::Id, RenderPass*> RenderPassIdHashMap;
 }  // namespace cc
 
 #endif  // CC_QUADS_RENDER_PASS_H_