1 2 /* 3 * Copyright 2006 The Android Open Source Project 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 10 #ifndef SkTableMaskFilter_DEFINED 11 #define SkTableMaskFilter_DEFINED 12 13 #include "SkMaskFilter.h" 14 #include "SkScalar.h" 15 16 /** \class SkTableMaskFilter 17 18 Applies a table lookup on each of the alpha values in the mask. 19 Helper methods create some common tables (e.g. gamma, clipping) 20 */ 21 class SkTableMaskFilter : public SkMaskFilter { 22 public: 23 SkTableMaskFilter(); 24 SkTableMaskFilter(const uint8_t table[256]); 25 virtual ~SkTableMaskFilter(); 26 27 void setTable(const uint8_t table[256]); 28 29 /** Utility that sets the gamma table 30 */ 31 static void MakeGammaTable(uint8_t table[256], SkScalar gamma); 32 33 /** Utility that creates a clipping table: clamps values below min to 0 34 and above max to 255, and rescales the remaining into 0..255 35 */ 36 static void MakeClipTable(uint8_t table[256], uint8_t min, uint8_t max); 37 38 static SkTableMaskFilter* CreateGamma(SkScalar gamma) { 39 uint8_t table[256]; 40 MakeGammaTable(table, gamma); 41 return SkNEW_ARGS(SkTableMaskFilter, (table)); 42 } 43 44 static SkTableMaskFilter* CreateClip(uint8_t min, uint8_t max) { 45 uint8_t table[256]; 46 MakeClipTable(table, min, max); 47 return SkNEW_ARGS(SkTableMaskFilter, (table)); 48 } 49 50 // overrides from SkMaskFilter 51 virtual SkMask::Format getFormat(); 52 virtual bool filterMask(SkMask*, const SkMask&, const SkMatrix&, SkIPoint*); 53 54 // overrides from SkFlattenable 55 virtual void flatten(SkFlattenableWriteBuffer& wb); 56 virtual Factory getFactory(); 57 58 protected: 59 SkTableMaskFilter(SkFlattenableReadBuffer& rb); 60 static SkFlattenable* Factory(SkFlattenableReadBuffer&); 61 62 private: 63 uint8_t fTable[256]; 64 65 typedef SkMaskFilter INHERITED; 66 }; 67 68 #endif 69 70
