1 /* 2 * Copyright 2024 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 #pragma once 17 18 #include <SkRuntimeEffect.h> 19 #include <SkShader.h> 20 21 namespace android { 22 namespace renderengine { 23 namespace skia { 24 25 /** 26 * Generates a shader for computing a gainmap, given an SDR base image and its idealized HDR 27 * rendition. The shader follows the procedure in the UltraHDR spec: 28 * https://developer.android.com/media/platform/hdr-image-format#gain_map-generation, but makes some 29 * simplifying assumptions about metadata typical for RenderEngine's usage. 30 */ 31 class GainmapFactory { 32 public: 33 GainmapFactory(); 34 // Generates the gainmap shader. The hdrSdrRatio is the max_content_boost in the UltraHDR 35 // specification. 36 sk_sp<SkShader> createSkShader(const sk_sp<SkShader>& sdr, const sk_sp<SkShader>& hdr, 37 float hdrSdrRatio); 38 39 private: 40 sk_sp<SkRuntimeEffect> mEffect; 41 }; 42 } // namespace skia 43 } // namespace renderengine 44 } // namespace android 45