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();
+        bool fDrawPathToCompressedTexture;

[bsalomon, 2014/08/11 19:00:47]

Should we label this field experimental or something? I imagine in the future we
will either always use it or not based on what the testing looks like.

[krajcevski, 2014/08/11 19:09:55]

Done.

+    };
+
     /**
      * 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 249 matching lines @@
 
     /**
      *  Temporarily override the true max texture size. Note: an override
      *  larger then the true max texture size will have no effect.
      *  This entry point is mainly meant for testing texture size dependent
      *  features and is only available if defined outside of Skia (see
      *  bleed GM.
      */
     void setMaxTextureSizeOverride(int maxTextureSizeOverride);
 
+    /**
+     *  This returns true if the underlying graphics device and system is
+     *  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.
+     */
+    bool supportsDrawPathToCompressedTexture() const;

[bsalomon, 2014/08/11 19:00:47]

Does this need to be public? It feels like we're exposing an implementation
detail that most users shouldn't care about.

[krajcevski, 2014/08/11 19:09:55]

I moved it to the "for internal use only" section.

+
     ///////////////////////////////////////////////////////////////////////////
     // Render targets
 
     /**
      * Sets the render target.
      * @param target    the render target to set.
      */
     void setRenderTarget(GrRenderTarget* target) {
         fRenderTarget.reset(SkSafeRef(target));
     }
@@ skipping 644 matching lines @@
     int                             fUPMToPMConversion;
 
     struct CleanUpData {
         PFCleanUpFunc fFunc;
         void*         fInfo;
     };
 
     SkTDArray<CleanUpData>          fCleanUpData;
 
     int                             fMaxTextureSizeOverride;
+    bool                            fSupportsDrawPathToCompressed;
 
     GrContext(); // init must be called after the constructor.
-    bool init(GrBackend, GrBackendContext);
+    bool init(GrBackend, GrBackendContext, const Options& opts);
 
     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*);
 
     void internalDrawPath(GrDrawTarget* target, bool useAA, const SkPath& path,
@@ skipping 125 matching lines @@
     }
 
     GrTexture* texture() { return fTexture; }
 
 private:
     GrContext*                    fContext;
     GrTexture*                    fTexture;
 };
 
 #endif