1caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy/* 2caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy * Copyright (C) 2017 The Android Open Source Project 3caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy * 4caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy * Licensed under the Apache License, Version 2.0 (the "License"); 5caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy * you may not use this file except in compliance with the License. 6caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy * You may obtain a copy of the License at 7caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy * 8caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy * http://www.apache.org/licenses/LICENSE-2.0 9caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy * 10caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy * Unless required by applicable law or agreed to in writing, software 11caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy * distributed under the License is distributed on an "AS IS" BASIS, 12caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy * See the License for the specific language governing permissions and 14caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy * limitations under the License. 15caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy */ 16caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy 17caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy#include "Color.h" 18caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy 19caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy#include <cmath> 20caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy 21caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guynamespace android { 22caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guynamespace uirenderer { 23caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy 24caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guystatic inline bool almostEqual(float a, float b) { 25caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy return std::abs(a - b) < 1e-2f; 26caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy} 27caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy 28caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guybool transferFunctionCloseToSRGB(const SkColorSpace* colorSpace) { 29caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy if (colorSpace == nullptr) return true; 30caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy if (colorSpace->isSRGB()) return true; 31caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy 32caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy SkColorSpaceTransferFn transferFunction; 33caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy if (colorSpace->isNumericalTransferFn(&transferFunction)) { 34caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy // sRGB transfer function params: 35caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy const float sRGBParamA = 1 / 1.055f; 36caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy const float sRGBParamB = 0.055f / 1.055f; 37caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy const float sRGBParamC = 1 / 12.92f; 38caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy const float sRGBParamD = 0.04045f; 39caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy const float sRGBParamE = 0.0f; 40caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy const float sRGBParamF = 0.0f; 41caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy const float sRGBParamG = 2.4f; 42caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy 43caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy // This comparison will catch Display P3 44caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy return 45caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy almostEqual(sRGBParamA, transferFunction.fA) 46caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy && almostEqual(sRGBParamB, transferFunction.fB) 47caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy && almostEqual(sRGBParamC, transferFunction.fC) 48caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy && almostEqual(sRGBParamD, transferFunction.fD) 49caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy && almostEqual(sRGBParamE, transferFunction.fE) 50caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy && almostEqual(sRGBParamF, transferFunction.fF) 51caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy && almostEqual(sRGBParamG, transferFunction.fG); 52caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy } 53caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy 54caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy return false; 55caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy} 56caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy 57caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy}; // namespace uirenderer 58caaaa66e57293e4a6f312649bf472eab84d5c7feRomain Guy}; // namespace android 59