1 /* 2 * Copyright (C) 2017 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "Color.h" 18 19 #include <cmath> 20 21 namespace android { 22 namespace uirenderer { 23 24 static inline bool almostEqual(float a, float b) { 25 return std::abs(a - b) < 1e-2f; 26 } 27 28 bool transferFunctionCloseToSRGB(const SkColorSpace* colorSpace) { 29 if (colorSpace == nullptr) return true; 30 if (colorSpace->isSRGB()) return true; 31 32 SkColorSpaceTransferFn transferFunction; 33 if (colorSpace->isNumericalTransferFn(&transferFunction)) { 34 // sRGB transfer function params: 35 const float sRGBParamA = 1 / 1.055f; 36 const float sRGBParamB = 0.055f / 1.055f; 37 const float sRGBParamC = 1 / 12.92f; 38 const float sRGBParamD = 0.04045f; 39 const float sRGBParamE = 0.0f; 40 const float sRGBParamF = 0.0f; 41 const float sRGBParamG = 2.4f; 42 43 // This comparison will catch Display P3 44 return 45 almostEqual(sRGBParamA, transferFunction.fA) 46 && almostEqual(sRGBParamB, transferFunction.fB) 47 && almostEqual(sRGBParamC, transferFunction.fC) 48 && almostEqual(sRGBParamD, transferFunction.fD) 49 && almostEqual(sRGBParamE, transferFunction.fE) 50 && almostEqual(sRGBParamF, transferFunction.fF) 51 && almostEqual(sRGBParamG, transferFunction.fG); 52 } 53 54 return false; 55 } 56 57 }; // namespace uirenderer 58 }; // namespace android 59
