Recycle stencil buffers across render targets.

src/gpu/GrStencilBuffer.h

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef GrStencilBuffer_DEFINED
@@ skipping 29 matching lines @@
 
     // called to determine if we have to render the clip into SB.
     bool mustRenderClip(int32_t clipStackGenID,
                         const SkIRect& clipSpaceRect,
                         const SkIPoint clipSpaceToStencilOffset) const {
         return fLastClipStackGenID != clipStackGenID ||
                fLastClipSpaceOffset != clipSpaceToStencilOffset ||
                !fLastClipStackRect.contains(clipSpaceRect);
     }
 
-    static void ComputeKey(int width, int height, int sampleCnt, GrScratchKey* key);
+    // We create a unique stencil buffer at each width, height and sampleCnt and share it for
+    // all render targets that require a stencil with those params.
+    static void ComputeSharedStencilBufferKey(int width, int height, int sampleCnt,
+                                              GrUniqueKey* key);
 
 protected:
     GrStencilBuffer(GrGpu* gpu, LifeCycle lifeCycle, int width, int height, int bits, int sampleCnt)
         : GrGpuResource(gpu, lifeCycle)
         , fWidth(width)
         , fHeight(height)
         , fBits(bits)
         , fSampleCnt(sampleCnt)
         , fLastClipStackGenID(SkClipStack::kInvalidGenID) {
-        if (kCached_LifeCycle == lifeCycle) {
-            GrScratchKey key;
-            ComputeKey(width, height, sampleCnt, &key);
-            this->setScratchKey(key);
-        }
         fLastClipStackRect.setEmpty();
     }
 
 private:
 
     int fWidth;
     int fHeight;
     int fBits;
     int fSampleCnt;
 
     int32_t     fLastClipStackGenID;
     SkIRect     fLastClipStackRect;
     SkIPoint    fLastClipSpaceOffset;
 
     typedef GrGpuResource INHERITED;
 };
 
 #endif