More framework support for TransferBuffers

src/gpu/GrResourceProvider.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 GrResourceProvider_DEFINED
 #define GrResourceProvider_DEFINED
 
@@ skipping 94 matching lines @@
 
     enum BufferUsage {
         /** Caller intends to specify the buffer data rarely with respect to the number of draws
             that read the data. */
         kStatic_BufferUsage,
         /** Caller intends to respecify the buffer data frequently between draws. */
         kDynamic_BufferUsage,
     };
     GrIndexBuffer* createIndexBuffer(size_t size, BufferUsage, uint32_t flags);
     GrVertexBuffer* createVertexBuffer(size_t size, BufferUsage, uint32_t flags);
+    enum TransferType {

[bsalomon, 2015/12/18 15:24:38]

We could put this in GrTypesPriv.h if you anticipate having a bunch of redefs of
this basic idea.

[jvanverth1, 2016/01/04 21:24:09]

Done.

+        /** Caller intends to use the buffer to transfer data to the GPU */
+        kCpuToGpu_TransferType,
+        /** Caller intends to use the buffer to transfer data from the GPU */
+        kGpuToCpu_TransferType
+    };    
+    GrTransferBuffer* createTransferBuffer(size_t size, TransferType, uint32_t flags);
 
     GrTexture* createApproxTexture(const GrSurfaceDesc& desc, uint32_t flags) {
         SkASSERT(0 == flags || kNoPendingIO_Flag == flags);
         return this->internalCreateApproxTexture(desc, flags);
     }
 
     /**  Returns a GrBatchAtlas. This function can be called anywhere, but the returned atlas should
      *   only be used inside of GrBatch::generateGeometry
      *   @param GrPixelConfig    The pixel config which this atlas will store
      *   @param width            width in pixels of the atlas
@@ skipping 28 matching lines @@
                                                     const GrUniqueKey& key);
 
     const GrIndexBuffer* createQuadIndexBuffer();
 
     GrUniqueKey fQuadIndexBufferKey;
 
     typedef GrTextureProvider INHERITED;
 };
 
 #endif