clear stencil buffer using special purpose FBO

src/gpu/GrGpu.cpp

 
 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGpu.h"
@@ skipping 79 matching lines @@
     SkAutoTUnref<GrStencilBuffer> sb(static_cast<GrStencilBuffer*>(
         this->getContext()->getResourceCache()->findAndRefUniqueResource(sbKey)));
     if (sb) {
         if (this->attachStencilBufferToRenderTarget(sb, rt)) {
             rt->renderTargetPriv().didAttachStencilBuffer(sb);
             return true;
         }
         return false;
     }
     if (this->createStencilBufferForRenderTarget(rt, width, height)) {
-        // Right now we're clearing the stencil buffer here after it is
-        // attached to an RT for the first time. When we start matching
-        // stencil buffers with smaller color targets this will no longer
-        // be correct because it won't be guaranteed to clear the entire
-        // sb.
-        // We used to clear down in the GL subclass using a special purpose
-        // FBO. But iOS doesn't allow a stencil-only FBO. It reports unsupported
-        // FBO status.
-        this->clearStencil(rt);
         GrStencilBuffer* sb = rt->renderTargetPriv().getStencilBuffer();
         sb->resourcePriv().setUniqueKey(sbKey);
         return true;
     } else {
         return false;
     }
 }
 
 GrTexture* GrGpu::wrapBackendTexture(const GrBackendTextureDesc& desc) {
     this->handleDirtyContext();
@@ skipping 193 matching lines @@
                       GrDrawTarget::PathIndexType indexType,
                       const float transformValues[],
                       GrDrawTarget::PathTransformType transformType,
                       int count,
                       const GrStencilSettings& stencilSettings) {
     this->handleDirtyContext();
     pathRange->willDrawPaths(indices, indexType, count);
     this->onDrawPaths(args, pathRange, indices, indexType, transformValues,
                       transformType, count, stencilSettings);
 }