Make GM render to render targets that are also textures.

include/gpu/SkGpuDevice.h

 
 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 
 #ifndef SkGpuDevice_DEFINED
 #define SkGpuDevice_DEFINED
 
 #include "SkGr.h"
 #include "SkBitmap.h"
 #include "SkDevice.h"
 #include "SkRegion.h"
 #include "GrContext.h"
 
 struct SkDrawProcs;
 struct GrSkDrawProcs;
 class GrTextContext;
 
 /**
  *  Subclass of SkDevice, which directs all drawing to the GrGpu owned by the
  *  canvas.
  */
 class SK_API SkGpuDevice : public SkDevice {
 public:
+
+    /**
+     * Creates an SkGpuDevice from a GrSurface. This will fail if the surface is not a render
+     * target. The caller owns a ref on the returned device.
+     */
+    static SkGpuDevice* Create(GrSurface* surface);
+
     /**
      *  New device that will create an offscreen renderTarget based on the
      *  config, width, height, and sampleCount. The device's storage will not
      *  count against the GrContext's texture cache budget. The device's pixels
-     *  will be uninitialized.
+     *  will be uninitialized. TODO: This can fail, replace with a factory function.
      */
     SkGpuDevice(GrContext*, SkBitmap::Config, int width, int height, int sampleCount = 0);
 
     /**
      *  New device that will render to the specified renderTarget.
+     *  DEPRECATED: Use Create(surface)
      */
     SkGpuDevice(GrContext*, GrRenderTarget*);
 
     /**
      *  New device that will render to the texture (as a rendertarget).
      *  The GrTexture's asRenderTarget() must be non-NULL or device will not
      *  function.
+     *  DEPRECATED: Use Create(surface)
      */
     SkGpuDevice(GrContext*, GrTexture*);
 
     virtual ~SkGpuDevice();
 
     GrContext* context() const { return fContext; }
 
     virtual SkGpuRenderTarget* accessRenderTarget() SK_OVERRIDE;
 
     // overrides from SkDevice
@@ skipping 119 matching lines @@
 
     /**
      * Returns non-initialized instance.
      */
     GrTextContext* getTextContext();
 
     typedef SkDevice INHERITED;
 };
 
 #endif