nsCSSColorUtils.h (1987B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */ 3 /* This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 /* functions that manipulate colors */ 8 9 #ifndef __nsCSSColorUtils_h 10 #define __nsCSSColorUtils_h 11 12 #include "nsColor.h" 13 14 // "Sufficient contrast" is determined by 15 // "Techniques For Accessibility Evalution And Repair Tools". 16 // See http://www.w3.org/TR/AERT#color-contrast 17 #define NS_SUFFICIENT_LUMINOSITY_DIFFERENCE 125000 18 // NS_SUFFICIENT_LUMINOSITY_DIFFERENCE is the a11y standard for text 19 // on a background. Use 20% of that standard since we have a background 20 // on top of another background 21 #define NS_SUFFICIENT_LUMINOSITY_DIFFERENCE_BG \ 22 (NS_SUFFICIENT_LUMINOSITY_DIFFERENCE / 5) 23 24 #define NS_LUMINOSITY_DIFFERENCE(a, b) \ 25 int32_t(mozilla::Abs(NS_GetLuminosity(a | 0xff000000) - \ 26 NS_GetLuminosity(b | 0xff000000))) 27 28 // Maximum value that NS_GetLuminosity can return. 29 #define NS_MAX_LUMINOSITY 255000 30 31 // To determine 3D colors for groove / ridge borders based on the border color 32 void NS_GetSpecial3DColors(nscolor aResult[2], nscolor aBorderColor); 33 34 // Determins brightness for a specific color 35 int NS_GetBrightness(uint8_t aRed, uint8_t aGreen, uint8_t aBlue); 36 37 // Get Luminosity of a specific color. That is same as Y of YIQ color space. 38 // The range of return value is 0 to NS_MAX_LUMINOSITY. 39 int32_t NS_GetLuminosity(nscolor aColor); 40 41 // function to convert from RGBA color space to HSVA color space 42 void NS_RGB2HSV(nscolor aColor, uint16_t& aHue, uint16_t& aSat, 43 uint16_t& aValue, uint8_t& aAlpha); 44 45 // function to convert from HSVA color space to RGBA color space 46 void NS_HSV2RGB(nscolor& aColor, uint16_t aHue, uint16_t aSat, uint16_t aValue, 47 uint8_t aAlpha); 48 49 #endif