| /* |
| * Copyright (C) 2017, 2020 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
| * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "config.h" |
| #include "ColorUtilities.h" |
| |
| namespace WebCore { |
| |
| SRGBA<float> premultiplied(const SRGBA<float>& color) |
| { |
| auto [r, g, b, a] = color; |
| return { r * a, g * a, b * a, a }; |
| } |
| |
| SRGBA<float> unpremultiplied(const SRGBA<float>& color) |
| { |
| auto [r, g, b, a] = color; |
| if (!a) |
| return color; |
| return makeFromComponentsClampingExceptAlpha<SRGBA<float>>(r / a, g / a, b / a, a); |
| } |
| |
| SRGBA<uint8_t> premultipliedFlooring(SRGBA<uint8_t> color) |
| { |
| auto [r, g, b, a] = color; |
| if (!a) |
| return { 0, 0, 0, 0 }; |
| if (a == 255) |
| return color; |
| return makeFromComponentsClampingExceptAlpha<SRGBA<uint8_t>>(fastDivideBy255(r * a), fastDivideBy255(g * a), fastDivideBy255(b * a), a); |
| } |
| |
| SRGBA<uint8_t> premultipliedCeiling(SRGBA<uint8_t> color) |
| { |
| auto [r, g, b, a] = color; |
| if (!a) |
| return { 0, 0, 0, 0 }; |
| if (a == 255) |
| return color; |
| return makeFromComponentsClampingExceptAlpha<SRGBA<uint8_t>>(fastDivideBy255(r * a + 254), fastDivideBy255(g * a + 254), fastDivideBy255(b * a + 254), a); |
| } |
| |
| static inline uint16_t unpremultipliedComponentByte(uint8_t c, uint8_t a) |
| { |
| return (fastMultiplyBy255(c) + a - 1) / a; |
| } |
| |
| SRGBA<uint8_t> unpremultiplied(SRGBA<uint8_t> color) |
| { |
| auto [r, g, b, a] = color; |
| if (!a || a == 255) |
| return color; |
| return makeFromComponentsClampingExceptAlpha<SRGBA<uint8_t>>(unpremultipliedComponentByte(r, a), unpremultipliedComponentByte(g, a), unpremultipliedComponentByte(b, a), a); |
| } |
| |
| } // namespace WebCore |