Gamma correction for distance field text.

src/core/SkMaskGamma.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 SkMaskGamma_DEFINED
 #define SkMaskGamma_DEFINED
 
@@ skipping 118 matching lines @@
     /** The type of the mask pre-blend which will be returned from preBlend(SkColor). */
     typedef SkTMaskPreBlend<R_LUM_BITS, G_LUM_BITS, B_LUM_BITS> PreBlend;
 
     /**
      * Provides access to the tables appropriate for converting linear alpha
      * values into gamma correcting alpha values when drawing the given color
      * through the mask. The destination color will be approximated.
      */
     PreBlend preBlend(SkColor color) const;
 
+    /**
+     * Get dimensions for the full table set, so it can be allocated as a block.
+     */
+    void getGammaTableDimensions(int* tableWidth, int* numTables) const {
+        *tableWidth = 256;
+        *numTables = (1 << MAX_LUM_BITS);
+    }
+
+    /**
+     * Provides direct access to the full table set, so it can be uploaded
+     * into a texture.
+     */
+    const uint8_t* getGammaTables() const {
+        return (const uint8_t*) fGammaTables;
+    }
+    
 private:
     static const int MAX_LUM_BITS =
           B_LUM_BITS > (R_LUM_BITS > G_LUM_BITS ? R_LUM_BITS : G_LUM_BITS)
         ? B_LUM_BITS : (R_LUM_BITS > G_LUM_BITS ? R_LUM_BITS : G_LUM_BITS);
     uint8_t fGammaTables[1 << MAX_LUM_BITS][256];
     bool fIsLinear;
 
     typedef SkRefCnt INHERITED;
 };
 
@@ skipping 58 matching lines @@
  */
 template<bool APPLY_LUT> static inline U8CPU sk_apply_lut_if(U8CPU component, const uint8_t*) {
     return component;
 }
 template<> /*static*/ inline U8CPU sk_apply_lut_if<true>(U8CPU component, const uint8_t* lut) {
     return lut[component];
 }
 ///@}
 
 #endif