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 /** Utility that sets the gamma table 22 */ 23 static void MakeGammaTable(uint8_t table[256], SkScalar gamma); 24 25 /** Utility that creates a clipping table: clamps values below min to 0 26 and above max to 255, and rescales the remaining into 0..255 27 */ 28 static void MakeClipTable(uint8_t table[256], uint8_t min, uint8_t max); 29 30 static SkMaskFilter* Create(const uint8_t table[256]) { 31 return new SkTableMaskFilter(table); 32 } 33 34 static SkMaskFilter* CreateGamma(SkScalar gamma) { 35 uint8_t table[256]; 36 MakeGammaTable(table, gamma); 37 return new SkTableMaskFilter(table); 38 } 39 40 static SkMaskFilter* CreateClip(uint8_t min, uint8_t max) { 41 uint8_t table[256]; 42 MakeClipTable(table, min, max); 43 return new SkTableMaskFilter(table); 44 } 45 46 SkMask::Format getFormat() const override; 47 bool filterMask(SkMask*, const SkMask&, const SkMatrix&, SkIPoint*) const override; 48 49 SK_TO_STRING_OVERRIDE() 50 SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTableMaskFilter) 51 52 protected: 53 ~SkTableMaskFilter() override; 54 55 void flatten(SkWriteBuffer&) const override; 56 57 private: 58 SkTableMaskFilter(); 59 explicit SkTableMaskFilter(const uint8_t table[256]); 60 61 uint8_t fTable[256]; 62 63 typedef SkMaskFilter INHERITED; 64 }; 65 66 #endif 67
