Change GR_COMPRESS_ALPHA_MASK from compile-time flag to run-time flag

include/gpu/GrContext.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 GrContext_DEFINED
 #define GrContext_DEFINED
 
@@ skipping 31 matching lines @@
 class GrVertexBuffer;
 class GrVertexBufferAllocPool;
 class GrStrokeInfo;
 class GrSoftwarePathRenderer;
 class SkStrokeRec;
 
 class SK_API GrContext : public SkRefCnt {
 public:
     SK_DECLARE_INST_COUNT(GrContext)
 
+    struct Options {
+        Options()
+            : fDrawPathToCompressedTexture(false)
+            { }
+
+        // EXPERIMENTAL
+        // May be removed in the future, or may become standard depending
+        // on the outcomes of a variety of internal tests.
+        bool fDrawPathToCompressedTexture;
+    };
+
     /**
      * Creates a GrContext for a backend context.
      */
-    static GrContext* Create(GrBackend, GrBackendContext);
+    static GrContext* Create(GrBackend, GrBackendContext, const Options* opts = NULL);
 
     virtual ~GrContext();
 
     /**
      * The GrContext normally assumes that no outsider is setting state
      * within the underlying 3D API's context/device/whatever. This call informs
      * the context that the state was modified and it should resend. Shouldn't
      * be called frequently for good performance.
      * The flag bits, state, is dpendent on which backend is used by the
      * context, either GL or D3D (possible in future).
@@ skipping 866 matching lines @@
     GrStencilBuffer* findStencilBuffer(int width, int height, int sampleCnt);
 
     GrPathRenderer* getPathRenderer(
                     const SkPath& path,
                     const SkStrokeRec& stroke,
                     const GrDrawTarget* target,
                     bool allowSW,
                     GrPathRendererChain::DrawType drawType = GrPathRendererChain::kColor_DrawType,
                     GrPathRendererChain::StencilSupport* stencilSupport = NULL);
 
+    /**
+     *  This returns true if the underlying graphics device and system is

[bsalomon, 2014/08/11 20:51:32]

update comment?

+     *  capable of drawing paths to compressed textures. This generally provides
+     *  a speedup on mobile devices with advanced GPUs, but it only gets turned
+     *  on when there is a clear speedup benefit.
+     */
+    const Options& getOptions() const { return fOptions; }
+
 #if GR_CACHE_STATS
     void printCacheStats() const;
 #endif
 
 private:
     // Used to indicate whether a draw should be performed immediately or queued in fDrawBuffer.
     enum BufferedDraw {
         kYes_BufferedDraw,
         kNo_BufferedDraw,
     };
@@ skipping 28 matching lines @@
 
     struct CleanUpData {
         PFCleanUpFunc fFunc;
         void*         fInfo;
     };
 
     SkTDArray<CleanUpData>          fCleanUpData;
 
     int                             fMaxTextureSizeOverride;
 
-    GrContext(); // init must be called after the constructor.
+    const Options                   fOptions;
+
+    GrContext(const Options&); // init must be called after the constructor.
     bool init(GrBackend, GrBackendContext);
 
     void setupDrawBuffer();
 
     class AutoRestoreEffects;
     class AutoCheckFlush;
     /// Sets the paint and returns the target to draw into. The paint can be NULL in which case the
     /// draw state is left unmodified.
     GrDrawTarget* prepareToDraw(const GrPaint*, BufferedDraw, AutoRestoreEffects*, AutoCheckFlush*);
 
@@ skipping 126 matching lines @@
     }
 
     GrTexture* texture() { return fTexture; }
 
 private:
     GrContext*                    fContext;
     GrTexture*                    fTexture;
 };
 
 #endif