Gamma correction for distance field text.

src/core/SkScalerContext.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkScalerContext_DEFINED
 #define SkScalerContext_DEFINED
 
@@ skipping 166 matching lines @@
     */
     SkUnichar glyphIDToChar(uint16_t glyphID);
 
     unsigned    getGlyphCount() { return this->generateGlyphCount(); }
     void        getAdvance(SkGlyph*);
     void        getMetrics(SkGlyph*);
     void        getImage(const SkGlyph&);
     void        getPath(const SkGlyph&, SkPath*);
     void        getFontMetrics(SkPaint::FontMetrics*);
 
+    /** Return the size in bytes of the associated gamma lookup table
+     */
+    static size_t GetGammaLUTSize(SkScalar contrast, SkScalar paintGamma, SkScalar deviceGamma,
+                                  int* width, int* height);
+
+    /** Get the associated gamma lookup table. The 'data' pointer must point to pre-allocated
+        memory, with size in bytes greater than or equal to the return value of getGammaLUTSize().
+     */
+    static void   GetGammaLUTData(SkScalar contrast, SkScalar paintGamma, SkScalar deviceGamma,
+                                  void* data);
+
 #ifdef SK_BUILD_FOR_ANDROID
     unsigned getBaseGlyphCount(SkUnichar charCode);
 
     // This function must be public for SkTypeface_android.h, but should not be
     // called by other callers
     SkFontID findTypefaceIdForChar(SkUnichar uni);
 #endif
 
     static void MakeRec(const SkPaint&, const SkDeviceProperties* deviceProperties,
                         const SkMatrix*, Rec* rec);
@@ skipping 140 matching lines @@
     return static_cast<SkPaint::Hinting>(hint);
 }
 
 void SkScalerContextRec::setHinting(SkPaint::Hinting hinting) {
     fFlags = (fFlags & ~SkScalerContext::kHinting_Mask) |
                                 (hinting << SkScalerContext::kHinting_Shift);
 }
 
 
 #endif