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 virtual ~SkTableMaskFilter(); 22 23 /** Utility that sets the gamma table 24 */ 25 static void MakeGammaTable(uint8_t table[256], SkScalar gamma); 26 27 /** Utility that creates a clipping table: clamps values below min to 0 28 and above max to 255, and rescales the remaining into 0..255 29 */ 30 static void MakeClipTable(uint8_t table[256], uint8_t min, uint8_t max); 31 Create(const uint8_t table[256])32 static SkTableMaskFilter* Create(const uint8_t table[256]) { 33 return SkNEW_ARGS(SkTableMaskFilter, (table)); 34 } 35 CreateGamma(SkScalar gamma)36 static SkTableMaskFilter* CreateGamma(SkScalar gamma) { 37 uint8_t table[256]; 38 MakeGammaTable(table, gamma); 39 return SkNEW_ARGS(SkTableMaskFilter, (table)); 40 } 41 CreateClip(uint8_t min,uint8_t max)42 static SkTableMaskFilter* CreateClip(uint8_t min, uint8_t max) { 43 uint8_t table[256]; 44 MakeClipTable(table, min, max); 45 return SkNEW_ARGS(SkTableMaskFilter, (table)); 46 } 47 48 virtual SkMask::Format getFormat() const SK_OVERRIDE; 49 virtual bool filterMask(SkMask*, const SkMask&, const SkMatrix&, 50 SkIPoint*) const SK_OVERRIDE; 51 52 SK_TO_STRING_OVERRIDE() 53 SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTableMaskFilter) 54 55 protected: 56 SkTableMaskFilter(); 57 explicit SkTableMaskFilter(const uint8_t table[256]); 58 explicit SkTableMaskFilter(SkReadBuffer& rb); 59 virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE; 60 61 private: 62 uint8_t fTable[256]; 63 64 typedef SkMaskFilter INHERITED; 65 }; 66 67 #endif 68