Add flag for SkGpuSurface creation to enable distance fields.

include/core/SkSurface.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkSurface_DEFINED
 #define SkSurface_DEFINED
 
@@ skipping 38 matching lines @@
     /**
      *  Helper version of NewRaster. It creates a SkImageInfo with the
      *  specified width and height, and populates the rest of info to match
      *  pixels in SkPMColor format.
      */
     static SkSurface* NewRasterPMColor(int width, int height) {
         return NewRaster(SkImageInfo::MakeN32Premul(width, height));
     }
 
     /**
+     *  Text rendering modes that can be passed to NewRenderTarget*
+     */
+    enum TextRenderMode {
+        /**
+         *  This will use the standard text rendering method
+         */
+        kStandard_TextRenderMode,
+        /**
+         *  This will use signed distance fields for text rendering when possible
+         */
+        kDistanceField_TextRenderMode,
+    };
+
+    /**
      *  Return a new surface using the specified render target.
      */
-    static SkSurface* NewRenderTargetDirect(GrRenderTarget*);
+    static SkSurface* NewRenderTargetDirect(GrRenderTarget*,
+                                            TextRenderMode trm = kStandard_TextRenderMode);
 
     /**
      *  Return a new surface whose contents will be drawn to an offscreen
      *  render target, allocated by the surface.
      */
-    static SkSurface* NewRenderTarget(GrContext*, const SkImageInfo&, int sampleCount = 0);
+    static SkSurface* NewRenderTarget(GrContext*, const SkImageInfo&, int sampleCount = 0,
+                                      TextRenderMode trm = kStandard_TextRenderMode);
 
     /**
      *  Return a new surface whose contents will be drawn to an offscreen
      *  render target, allocated by the surface from the scratch texture pool
      *  managed by the GrContext. The scratch texture pool serves the purpose
      *  of retaining textures after they are no longer in use in order to
      *  re-use them later without having to re-allocate.  Scratch textures
      *  should be used in cases where high turnover is expected. This allows,
      *  for example, the copy on write to recycle a texture from a recently
      *  released SkImage snapshot of the surface.
      *  Note: Scratch textures count against the GrContext's cached resource
      *  budget.
      */
-    static SkSurface* NewScratchRenderTarget(GrContext*, const SkImageInfo&, int sampleCount = 0);
+    static SkSurface* NewScratchRenderTarget(GrContext*, const SkImageInfo&, int sampleCount = 0,
+                                             TextRenderMode trm = kStandard_TextRenderMode);
 
     int width() const { return fWidth; }
     int height() const { return fHeight; }
 
     /**
      *  Returns a unique non-zero, unique value identifying the content of this
      *  surface. Each time the content is changed changed, either by drawing
      *  into this surface, or explicitly calling notifyContentChanged()) this
      *  method will return a new value.
      *
@@ skipping 86 matching lines @@
 
 private:
     const int   fWidth;
     const int   fHeight;
     uint32_t    fGenerationID;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif