Join non-overlapping Xfer barriers

src/gpu/GrTargetCommands.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrTargetCommands_DEFINED
 #define GrTargetCommands_DEFINED
 
@@ skipping 15 matching lines @@
 class GrTargetCommands : ::SkNoncopyable {
     struct SetState;
 
 public:
     GrTargetCommands(GrGpu* gpu,
                      GrVertexBufferAllocPool* vertexPool,
                      GrIndexBufferAllocPool* indexPool)
         : fCmdBuffer(kCmdBufferInitialSizeInBytes)
         , fPrevState(NULL)
         , fBatchTarget(gpu, vertexPool, indexPool)
-        , fDrawBatch(NULL) {
+        , fDrawBatch(NULL)
+        , fXferBarrier(NULL) {
     }
 
     class Cmd : ::SkNoncopyable {
     public:
         enum CmdType {
             kDraw_CmdType              = 1,
             kStencilPath_CmdType       = 2,
             kSetState_CmdType          = 3,
             kClear_CmdType             = 4,
             kCopySurface_CmdType       = 5,
@@ skipping 251 matching lines @@
         void execute(GrGpu*, const SetState*) override;
 
         // TODO it wouldn't be too hard to let batches allocate in the cmd buffer
         SkAutoTUnref<GrBatch>  fBatch;
 
     private:
         GrBatchTarget*         fBatchTarget;
     };
 
     struct XferBarrier : public Cmd {
-        XferBarrier(GrXferBarrierType type)
+        XferBarrier(GrXferBarrierType type, GrRenderTarget* rt)
             : Cmd(kXferBarrier_CmdType)
-            , fType(type) {}
+            , fType(type)
+            , fRenderTarget(rt) {}
 
         void execute(GrGpu*, const SetState*) override;
 
         const GrXferBarrierType   fType;
-        SkIRect                   fBounds;
+        SkIRect                   fReadBounds;
+        SkIRect                   fInvalidBounds;
+
+        // The cmd buffer keeps these ptrs alive.
+        GrRenderTarget* const                      fRenderTarget;
+        SkSTArray<4, const GrXferProcessor*, true> fXferProcessors;
     };
 
      static const int kCmdBufferInitialSizeInBytes = 8 * 1024;
 
      typedef void* TCmdAlign; // This wouldn't be enough align if a command used long double.
      typedef GrTRecorder<Cmd, TCmdAlign> CmdBuffer;
 
      CmdBuffer                           fCmdBuffer;
      SetState*                           fPrevState;
      GrBatchTarget                       fBatchTarget;
      // TODO hack until batch is everywhere
      GrTargetCommands::DrawBatch*        fDrawBatch;
+     XferBarrier*                        fXferBarrier;
 
      // This will go away when everything uses batch.  However, in the short term anything which
      // might be put into the GrInOrderDrawBuffer needs to make sure it closes the last batch
      void closeBatch();
 };
 
 #endif