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