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 #include "include/core/SkRefCnt.h" 12 #include "include/private/SkFixed.h" 13 #include "include/private/SkOnce.h" 14 #include "include/third_party/skcms/skcms.h" 15 #include <memory> 16 17 class SkData; 18 19 /** 20 * Describes a color gamut with primaries and a white point. 21 */ 22 struct SK_API SkColorSpacePrimaries { 23 float fRX; 24 float fRY; 25 float fGX; 26 float fGY; 27 float fBX; 28 float fBY; 29 float fWX; 30 float fWY; 31 32 /** 33 * Convert primaries and a white point to a toXYZD50 matrix, the preferred color gamut 34 * representation of SkColorSpace. 35 */ 36 bool toXYZD50(skcms_Matrix3x3* toXYZD50) const; 37 }; 38 39 namespace SkNamedTransferFn { 40 41 // Like SkNamedGamut::kSRGB, keeping this bitwise exactly the same as skcms makes things fastest. 42 static constexpr skcms_TransferFunction kSRGB = 43 { 2.4f, (float)(1/1.055), (float)(0.055/1.055), (float)(1/12.92), 0.04045f, 0.0f, 0.0f }; 44 45 static constexpr skcms_TransferFunction k2Dot2 = 46 { 2.2f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f }; 47 48 static constexpr skcms_TransferFunction kLinear = 49 { 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f }; 50 51 static constexpr skcms_TransferFunction kRec2020 = 52 {2.22222f, 0.909672f, 0.0903276f, 0.222222f, 0.0812429f, 0, 0}; 53 54 static constexpr skcms_TransferFunction kPQ = 55 {-2.0f, -107/128.0f, 1.0f, 32/2523.0f, 2413/128.0f, -2392/128.0f, 8192/1305.0f }; 56 57 static constexpr skcms_TransferFunction kHLG = 58 {-3.0f, 2.0f, 2.0f, 1/0.17883277f, 0.28466892f, 0.55991073f, 0.0f }; 59 60 } // namespace SkNamedTransferFn 61 62 namespace SkNamedGamut { 63 64 static constexpr skcms_Matrix3x3 kSRGB = {{ 65 // ICC fixed-point (16.16) representation, taken from skcms. Please keep them exactly in sync. 66 // 0.436065674f, 0.385147095f, 0.143066406f, 67 // 0.222488403f, 0.716873169f, 0.060607910f, 68 // 0.013916016f, 0.097076416f, 0.714096069f, 69 { SkFixedToFloat(0x6FA2), SkFixedToFloat(0x6299), SkFixedToFloat(0x24A0) }, 70 { SkFixedToFloat(0x38F5), SkFixedToFloat(0xB785), SkFixedToFloat(0x0F84) }, 71 { SkFixedToFloat(0x0390), SkFixedToFloat(0x18DA), SkFixedToFloat(0xB6CF) }, 72 }}; 73 74 static constexpr skcms_Matrix3x3 kAdobeRGB = {{ 75 // ICC fixed-point (16.16) repesentation of: 76 // 0.60974, 0.20528, 0.14919, 77 // 0.31111, 0.62567, 0.06322, 78 // 0.01947, 0.06087, 0.74457, 79 { SkFixedToFloat(0x9c18), SkFixedToFloat(0x348d), SkFixedToFloat(0x2631) }, 80 { SkFixedToFloat(0x4fa5), SkFixedToFloat(0xa02c), SkFixedToFloat(0x102f) }, 81 { SkFixedToFloat(0x04fc), SkFixedToFloat(0x0f95), SkFixedToFloat(0xbe9c) }, 82 }}; 83 84 static constexpr skcms_Matrix3x3 kDisplayP3 = {{ 85 { 0.515102f, 0.291965f, 0.157153f }, 86 { 0.241182f, 0.692236f, 0.0665819f }, 87 { -0.00104941f, 0.0418818f, 0.784378f }, 88 }}; 89 90 static constexpr skcms_Matrix3x3 kRec2020 = {{ 91 { 0.673459f, 0.165661f, 0.125100f }, 92 { 0.279033f, 0.675338f, 0.0456288f }, 93 { -0.00193139f, 0.0299794f, 0.797162f }, 94 }}; 95 96 static constexpr skcms_Matrix3x3 kXYZ = {{ 97 { 1.0f, 0.0f, 0.0f }, 98 { 0.0f, 1.0f, 0.0f }, 99 { 0.0f, 0.0f, 1.0f }, 100 }}; 101 102 } // namespace SkNamedGamut 103 104 class SK_API SkColorSpace : public SkNVRefCnt<SkColorSpace> { 105 public: 106 /** 107 * Create the sRGB color space. 108 */ 109 static sk_sp<SkColorSpace> MakeSRGB(); 110 111 /** 112 * Colorspace with the sRGB primaries, but a linear (1.0) gamma. 113 */ 114 static sk_sp<SkColorSpace> MakeSRGBLinear(); 115 116 /** 117 * Create an SkColorSpace from a transfer function and a row-major 3x3 transformation to XYZ. 118 */ 119 static sk_sp<SkColorSpace> MakeRGB(const skcms_TransferFunction& transferFn, 120 const skcms_Matrix3x3& toXYZ); 121 122 /** 123 * Create an SkColorSpace from a parsed (skcms) ICC profile. 124 */ 125 static sk_sp<SkColorSpace> Make(const skcms_ICCProfile&); 126 127 /** 128 * Convert this color space to an skcms ICC profile struct. 129 */ 130 void toProfile(skcms_ICCProfile*) const; 131 132 /** 133 * Returns true if the color space gamma is near enough to be approximated as sRGB. 134 */ 135 bool gammaCloseToSRGB() const; 136 137 /** 138 * Returns true if the color space gamma is linear. 139 */ 140 bool gammaIsLinear() const; 141 142 /** 143 * Sets |fn| to the transfer function from this color space. Returns true if the transfer 144 * function can be represented as coefficients to the standard ICC 7-parameter equation. 145 * Returns false otherwise (eg, PQ, HLG). 146 */ 147 bool isNumericalTransferFn(skcms_TransferFunction* fn) const; 148 149 /** 150 * Returns true and sets |toXYZD50| if the color gamut can be described as a matrix. 151 * Returns false otherwise. 152 */ 153 bool toXYZD50(skcms_Matrix3x3* toXYZD50) const; 154 155 /** 156 * Returns a hash of the gamut transformation to XYZ D50. Allows for fast equality checking 157 * of gamuts, at the (very small) risk of collision. 158 */ toXYZD50Hash()159 uint32_t toXYZD50Hash() const { return fToXYZD50Hash; } 160 161 /** 162 * Returns a color space with the same gamut as this one, but with a linear gamma. 163 * For color spaces whose gamut can not be described in terms of XYZ D50, returns 164 * linear sRGB. 165 */ 166 sk_sp<SkColorSpace> makeLinearGamma() const; 167 168 /** 169 * Returns a color space with the same gamut as this one, with with the sRGB transfer 170 * function. For color spaces whose gamut can not be described in terms of XYZ D50, returns 171 * sRGB. 172 */ 173 sk_sp<SkColorSpace> makeSRGBGamma() const; 174 175 /** 176 * Returns a color space with the same transfer function as this one, but with the primary 177 * colors rotated. For any XYZ space, this produces a new color space that maps RGB to GBR 178 * (when applied to a source), and maps RGB to BRG (when applied to a destination). For other 179 * types of color spaces, returns nullptr. 180 * 181 * This is used for testing, to construct color spaces that have severe and testable behavior. 182 */ 183 sk_sp<SkColorSpace> makeColorSpin() const; 184 185 /** 186 * Returns true if the color space is sRGB. 187 * Returns false otherwise. 188 * 189 * This allows a little bit of tolerance, given that we might see small numerical error 190 * in some cases: converting ICC fixed point to float, converting white point to D50, 191 * rounding decisions on transfer function and matrix. 192 * 193 * This does not consider a 2.2f exponential transfer function to be sRGB. While these 194 * functions are similar (and it is sometimes useful to consider them together), this 195 * function checks for logical equality. 196 */ 197 bool isSRGB() const; 198 199 /** 200 * Returns nullptr on failure. Fails when we fallback to serializing ICC data and 201 * the data is too large to serialize. 202 */ 203 sk_sp<SkData> serialize() const; 204 205 /** 206 * If |memory| is nullptr, returns the size required to serialize. 207 * Otherwise, serializes into |memory| and returns the size. 208 */ 209 size_t writeToMemory(void* memory) const; 210 211 static sk_sp<SkColorSpace> Deserialize(const void* data, size_t length); 212 213 /** 214 * If both are null, we return true. If one is null and the other is not, we return false. 215 * If both are non-null, we do a deeper compare. 216 */ 217 static bool Equals(const SkColorSpace*, const SkColorSpace*); 218 219 void transferFn(float gabcdef[7]) const; // DEPRECATED: Remove when webview usage is gone 220 void transferFn(skcms_TransferFunction* fn) const; 221 void invTransferFn(skcms_TransferFunction* fn) const; 222 void gamutTransformTo(const SkColorSpace* dst, skcms_Matrix3x3* src_to_dst) const; 223 transferFnHash()224 uint32_t transferFnHash() const { return fTransferFnHash; } hash()225 uint64_t hash() const { return (uint64_t)fTransferFnHash << 32 | fToXYZD50Hash; } 226 227 private: 228 friend class SkColorSpaceSingletonFactory; 229 230 SkColorSpace(const skcms_TransferFunction& transferFn, const skcms_Matrix3x3& toXYZ); 231 232 void computeLazyDstFields() const; 233 234 uint32_t fTransferFnHash; 235 uint32_t fToXYZD50Hash; 236 237 skcms_TransferFunction fTransferFn; 238 skcms_Matrix3x3 fToXYZD50; 239 240 mutable skcms_TransferFunction fInvTransferFn; 241 mutable skcms_Matrix3x3 fFromXYZD50; 242 mutable SkOnce fLazyDstFieldsOnce; 243 }; 244 245 #endif 246