1 /* 2 * Copyright 2016 Google Inc. 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 SkColorSpace_DEFINED 9 #define SkColorSpace_DEFINED 10 11 // Some terms 12 // 13 // PCS : Profile Connection Space : where color number values have an absolute meaning. 14 // Part of the work float is to convert colors to and from this space... 15 // src_linear_unit_floats --> PCS --> PCS' --> dst_linear_unit_floats 16 // 17 // Some nice documents 18 // 19 // http://www.cambridgeincolour.com/tutorials/color-space-conversion.htm 20 // https://www.w3.org/Graphics/Color/srgb 21 // http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html 22 // 23 24 #include "SkRefCnt.h" 25 26 struct SkFloat3 { 27 float fVec[3]; 28 29 void dump() const; 30 }; 31 32 struct SkFloat3x3 { 33 float fMat[9]; 34 35 void dump() const; 36 }; 37 38 struct SkPM4f; 39 void SkApply3x3ToPM4f(const SkFloat3x3&, const SkPM4f src[], SkPM4f dst[], int count); 40 41 class SkColorSpace : public SkRefCnt { 42 public: 43 enum Named { 44 kUnknown_Named, 45 kDevice_Named, 46 kSRGB_Named, 47 }; 48 49 /** 50 * Return a colorspace instance, given a 3x3 transform from linear_RGB to D50_XYZ 51 * and the src-gamma, return a ColorSpace 52 */ 53 static SkColorSpace* NewRGB(const SkFloat3x3& toXYZD50, const SkFloat3& gamma); 54 55 static SkColorSpace* NewNamed(Named); 56 static SkColorSpace* NewICC(const void*, size_t); 57 gamma()58 SkFloat3 gamma() const { return fGamma; } named()59 Named named() const { return fNamed; } uniqueID()60 uint32_t uniqueID() const { return fUniqueID; } 61 62 enum Result { 63 kFailure_Result, 64 kIdentity_Result, 65 kNormal_Result, 66 }; 67 68 /** 69 * Given a src and dst colorspace, return the 3x3 matrix that will convert src_linear_RGB 70 * values into dst_linear_RGB values. 71 */ 72 static Result Concat(const SkColorSpace* src, const SkColorSpace* dst, SkFloat3x3* result); 73 74 static void Test(); 75 void dump() const; 76 77 protected: 78 SkColorSpace(const SkFloat3x3& toXYZ, const SkFloat3& gamma, Named); 79 80 private: 81 const SkFloat3x3 fToXYZD50; 82 const SkFloat3 fGamma; 83 const uint32_t fUniqueID; 84 const Named fNamed; 85 }; 86 87 #endif 88