1 /* 2 * Copyright 2017 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 SkPngPriv_DEFINED 9 #define SkPngPriv_DEFINED 10 11 #include "include/core/SkTypes.h" 12 13 // We store kAlpha_8 images as GrayAlpha in png. Our private signal is significant bits for gray. 14 // If that is set to 1, we assume the gray channel can be ignored, and we output just alpha. 15 // We tried 0 at first, but png doesn't like a 0 sigbit for a channel it expects, hence we chose 1. 16 17 static constexpr int kGraySigBit_GrayAlphaIsJustAlpha = 1; 18 19 #endif 20