| /* |
| * Copyright (C) 2017 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" |
| |
| #include "Color.h" |
| #include <wtf/MathExtras.h> |
| |
| namespace WebCore { |
| |
| FloatComponents::FloatComponents(const Color& color) |
| { |
| color.getRGBA(components[0], components[1], components[2], components[3]); |
| } |
| |
| ColorComponents::ColorComponents(const FloatComponents& floatComponents) |
| { |
| components[0] = clampedColorComponent(floatComponents.components[0]); |
| components[1] = clampedColorComponent(floatComponents.components[1]); |
| components[2] = clampedColorComponent(floatComponents.components[2]); |
| components[3] = clampedColorComponent(floatComponents.components[3]); |
| } |
| |
| // These are the standard sRGB <-> linearRGB conversion functions (https://en.wikipedia.org/wiki/SRGB). |
| float linearToSRGBColorComponent(float c) |
| { |
| if (c < 0.0031308f) |
| return 12.92f * c; |
| |
| return clampTo<float>(1.055f * std::pow(c, 1.0f / 2.4f) - 0.055f, 0, 1); |
| } |
| |
| float sRGBToLinearColorComponent(float c) |
| { |
| if (c <= 0.04045f) |
| return c / 12.92f; |
| |
| return clampTo<float>(std::pow((c + 0.055f) / 1.055f, 2.4f), 0, 1); |
| } |
| |
| FloatComponents sRGBColorToLinearComponents(const Color& color) |
| { |
| float r, g, b, a; |
| color.getRGBA(r, g, b, a); |
| return { |
| sRGBToLinearColorComponent(r), |
| sRGBToLinearColorComponent(g), |
| sRGBToLinearColorComponent(b), |
| a |
| }; |
| } |
| |
| FloatComponents sRGBToLinearComponents(const FloatComponents& sRGBColor) |
| { |
| return { |
| sRGBToLinearColorComponent(sRGBColor.components[0]), |
| sRGBToLinearColorComponent(sRGBColor.components[1]), |
| sRGBToLinearColorComponent(sRGBColor.components[2]), |
| sRGBColor.components[3] |
| }; |
| } |
| |
| FloatComponents linearToSRGBComponents(const FloatComponents& linearRGB) |
| { |
| return { |
| linearToSRGBColorComponent(linearRGB.components[0]), |
| linearToSRGBColorComponent(linearRGB.components[1]), |
| linearToSRGBColorComponent(linearRGB.components[2]), |
| linearRGB.components[3] |
| }; |
| } |
| |
| // This is similar to sRGBToLinearColorComponent but for some reason |
| // https://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef |
| // doesn't use the standard sRGB -> linearRGB threshold of 0.04045. |
| static float sRGBToLinearColorComponentForLuminance(float c) |
| { |
| if (c <= 0.03928f) |
| return c / 12.92f; |
| |
| return clampTo<float>(std::pow((c + 0.055f) / 1.055f, 2.4f), 0, 1); |
| } |
| |
| float luminance(const FloatComponents& sRGBComponents) |
| { |
| // Values from https://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef |
| return 0.2126f * sRGBToLinearColorComponentForLuminance(sRGBComponents.components[0]) |
| + 0.7152f * sRGBToLinearColorComponentForLuminance(sRGBComponents.components[1]) |
| + 0.0722f * sRGBToLinearColorComponentForLuminance(sRGBComponents.components[2]); |
| } |
| |
| float contrastRatio(const FloatComponents& componentsA, const FloatComponents& componentsB) |
| { |
| // Uses the WCAG 2.0 definition of contrast ratio. |
| // https://www.w3.org/TR/WCAG20/#contrast-ratiodef |
| float lighterLuminance = luminance(componentsA); |
| float darkerLuminance = luminance(componentsB); |
| |
| if (lighterLuminance < darkerLuminance) |
| std::swap(lighterLuminance, darkerLuminance); |
| |
| return (lighterLuminance + 0.05) / (darkerLuminance + 0.05); |
| } |
| |
| FloatComponents sRGBToHSL(const FloatComponents& sRGBColor) |
| { |
| // http://en.wikipedia.org/wiki/HSL_color_space. |
| float r = sRGBColor.components[0]; |
| float g = sRGBColor.components[1]; |
| float b = sRGBColor.components[2]; |
| |
| float max = std::max(std::max(r, g), b); |
| float min = std::min(std::min(r, g), b); |
| float chroma = max - min; |
| |
| float hue; |
| if (!chroma) |
| hue = 0; |
| else if (max == r) |
| hue = (60.0f * ((g - b) / chroma)) + 360.0f; |
| else if (max == g) |
| hue = (60.0f * ((b - r) / chroma)) + 120.0f; |
| else |
| hue = (60.0f * ((r - g) / chroma)) + 240.0f; |
| |
| if (hue >= 360.0f) |
| hue -= 360.0f; |
| |
| hue /= 360.0f; |
| |
| float lightness = 0.5f * (max + min); |
| float saturation; |
| if (!chroma) |
| saturation = 0; |
| else if (lightness <= 0.5f) |
| saturation = (chroma / (max + min)); |
| else |
| saturation = (chroma / (2.0f - (max + min))); |
| |
| return { |
| hue, |
| saturation, |
| lightness, |
| sRGBColor.components[3] |
| }; |
| } |
| |
| // Hue is in the range 0-6, other args in 0-1. |
| static float calcHue(float temp1, float temp2, float hueVal) |
| { |
| if (hueVal < 0.0f) |
| hueVal += 6.0f; |
| else if (hueVal >= 6.0f) |
| hueVal -= 6.0f; |
| if (hueVal < 1.0f) |
| return temp1 + (temp2 - temp1) * hueVal; |
| if (hueVal < 3.0f) |
| return temp2; |
| if (hueVal < 4.0f) |
| return temp1 + (temp2 - temp1) * (4.0f - hueVal); |
| return temp1; |
| } |
| |
| // Explanation of this algorithm can be found in the CSS Color 4 Module |
| // specification at https://drafts.csswg.org/css-color-4/#hsl-to-rgb with |
| // further explanation available at http://en.wikipedia.org/wiki/HSL_color_space |
| FloatComponents HSLToSRGB(const FloatComponents& hslColor) |
| { |
| float hue = hslColor.components[0]; |
| float saturation = hslColor.components[1]; |
| float lightness = hslColor.components[2]; |
| |
| // Convert back to RGB. |
| if (!saturation) { |
| return { |
| lightness, |
| lightness, |
| lightness, |
| hslColor.components[3] |
| }; |
| } |
| |
| float temp2 = lightness <= 0.5f ? lightness * (1.0f + saturation) : lightness + saturation - lightness * saturation; |
| float temp1 = 2.0f * lightness - temp2; |
| |
| hue *= 6.0f; // calcHue() wants hue in the 0-6 range. |
| return { |
| calcHue(temp1, temp2, hue + 2.0f), |
| calcHue(temp1, temp2, hue), |
| calcHue(temp1, temp2, hue - 2.0f), |
| hslColor.components[3] |
| }; |
| } |
| |
| ColorMatrix::ColorMatrix() |
| { |
| makeIdentity(); |
| } |
| |
| ColorMatrix::ColorMatrix(float values[20]) |
| { |
| m_matrix[0][0] = values[0]; |
| m_matrix[0][1] = values[1]; |
| m_matrix[0][2] = values[2]; |
| m_matrix[0][3] = values[3]; |
| m_matrix[0][4] = values[4]; |
| |
| m_matrix[1][0] = values[5]; |
| m_matrix[1][1] = values[6]; |
| m_matrix[1][2] = values[7]; |
| m_matrix[1][3] = values[8]; |
| m_matrix[1][4] = values[9]; |
| |
| m_matrix[2][0] = values[10]; |
| m_matrix[2][1] = values[11]; |
| m_matrix[2][2] = values[12]; |
| m_matrix[2][3] = values[13]; |
| m_matrix[2][4] = values[14]; |
| |
| m_matrix[3][0] = values[15]; |
| m_matrix[3][1] = values[16]; |
| m_matrix[3][2] = values[17]; |
| m_matrix[3][3] = values[18]; |
| m_matrix[3][4] = values[19]; |
| } |
| |
| void ColorMatrix::makeIdentity() |
| { |
| memset(m_matrix, 0, sizeof(m_matrix)); |
| m_matrix[0][0] = 1; |
| m_matrix[1][1] = 1; |
| m_matrix[2][2] = 1; |
| m_matrix[3][3] = 1; |
| } |
| |
| ColorMatrix ColorMatrix::grayscaleMatrix(float amount) |
| { |
| ColorMatrix matrix; |
| |
| float oneMinusAmount = clampTo(1 - amount, 0.0, 1.0); |
| |
| // Values from https://www.w3.org/TR/filter-effects-1/#grayscaleEquivalent |
| matrix.m_matrix[0][0] = 0.2126f + 0.7874f * oneMinusAmount; |
| matrix.m_matrix[0][1] = 0.7152f - 0.7152f * oneMinusAmount; |
| matrix.m_matrix[0][2] = 0.0722f - 0.0722f * oneMinusAmount; |
| |
| matrix.m_matrix[1][0] = 0.2126f - 0.2126f * oneMinusAmount; |
| matrix.m_matrix[1][1] = 0.7152f + 0.2848f * oneMinusAmount; |
| matrix.m_matrix[1][2] = 0.0722f - 0.0722f * oneMinusAmount; |
| |
| matrix.m_matrix[2][0] = 0.2126f - 0.2126f * oneMinusAmount; |
| matrix.m_matrix[2][1] = 0.7152f - 0.7152f * oneMinusAmount; |
| matrix.m_matrix[2][2] = 0.0722f + 0.9278f * oneMinusAmount; |
| |
| return matrix; |
| } |
| |
| ColorMatrix ColorMatrix::saturationMatrix(float amount) |
| { |
| ColorMatrix matrix; |
| |
| // Values from https://www.w3.org/TR/filter-effects-1/#feColorMatrixElement |
| matrix.m_matrix[0][0] = 0.213f + 0.787f * amount; |
| matrix.m_matrix[0][1] = 0.715f - 0.715f * amount; |
| matrix.m_matrix[0][2] = 0.072f - 0.072f * amount; |
| |
| matrix.m_matrix[1][0] = 0.213f - 0.213f * amount; |
| matrix.m_matrix[1][1] = 0.715f + 0.285f * amount; |
| matrix.m_matrix[1][2] = 0.072f - 0.072f * amount; |
| |
| matrix.m_matrix[2][0] = 0.213f - 0.213f * amount; |
| matrix.m_matrix[2][1] = 0.715f - 0.715f * amount; |
| matrix.m_matrix[2][2] = 0.072f + 0.928f * amount; |
| |
| return matrix; |
| } |
| |
| ColorMatrix ColorMatrix::hueRotateMatrix(float angleInDegrees) |
| { |
| float cosHue = cos(deg2rad(angleInDegrees)); |
| float sinHue = sin(deg2rad(angleInDegrees)); |
| |
| ColorMatrix matrix; |
| |
| // Values from https://www.w3.org/TR/filter-effects-1/#feColorMatrixElement |
| matrix.m_matrix[0][0] = 0.213f + cosHue * 0.787f - sinHue * 0.213f; |
| matrix.m_matrix[0][1] = 0.715f - cosHue * 0.715f - sinHue * 0.715f; |
| matrix.m_matrix[0][2] = 0.072f - cosHue * 0.072f + sinHue * 0.928f; |
| |
| matrix.m_matrix[1][0] = 0.213f - cosHue * 0.213f + sinHue * 0.143f; |
| matrix.m_matrix[1][1] = 0.715f + cosHue * 0.285f + sinHue * 0.140f; |
| matrix.m_matrix[1][2] = 0.072f - cosHue * 0.072f - sinHue * 0.283f; |
| |
| matrix.m_matrix[2][0] = 0.213f - cosHue * 0.213f - sinHue * 0.787f; |
| matrix.m_matrix[2][1] = 0.715f - cosHue * 0.715f + sinHue * 0.715f; |
| matrix.m_matrix[2][2] = 0.072f + cosHue * 0.928f + sinHue * 0.072f; |
| |
| return matrix; |
| } |
| |
| ColorMatrix ColorMatrix::sepiaMatrix(float amount) |
| { |
| ColorMatrix matrix; |
| |
| float oneMinusAmount = clampTo(1 - amount, 0.0, 1.0); |
| |
| // Values from https://www.w3.org/TR/filter-effects-1/#sepiaEquivalent |
| matrix.m_matrix[0][0] = 0.393f + 0.607f * oneMinusAmount; |
| matrix.m_matrix[0][1] = 0.769f - 0.769f * oneMinusAmount; |
| matrix.m_matrix[0][2] = 0.189f - 0.189f * oneMinusAmount; |
| |
| matrix.m_matrix[1][0] = 0.349f - 0.349f * oneMinusAmount; |
| matrix.m_matrix[1][1] = 0.686f + 0.314f * oneMinusAmount; |
| matrix.m_matrix[1][2] = 0.168f - 0.168f * oneMinusAmount; |
| |
| matrix.m_matrix[2][0] = 0.272f - 0.272f * oneMinusAmount; |
| matrix.m_matrix[2][1] = 0.534f - 0.534f * oneMinusAmount; |
| matrix.m_matrix[2][2] = 0.131f + 0.869f * oneMinusAmount; |
| |
| return matrix; |
| } |
| |
| void ColorMatrix::transformColorComponents(FloatComponents& colorComonents) const |
| { |
| float red = colorComonents.components[0]; |
| float green = colorComonents.components[1]; |
| float blue = colorComonents.components[2]; |
| float alpha = colorComonents.components[3]; |
| |
| colorComonents.components[0] = m_matrix[0][0] * red + m_matrix[0][1] * green + m_matrix[0][2] * blue + m_matrix[0][3] * alpha + m_matrix[0][4]; |
| colorComonents.components[1] = m_matrix[1][0] * red + m_matrix[1][1] * green + m_matrix[1][2] * blue + m_matrix[1][3] * alpha + m_matrix[1][4]; |
| colorComonents.components[2] = m_matrix[2][0] * red + m_matrix[2][1] * green + m_matrix[2][2] * blue + m_matrix[2][3] * alpha + m_matrix[2][4]; |
| colorComonents.components[3] = m_matrix[3][0] * red + m_matrix[3][1] * green + m_matrix[3][2] * blue + m_matrix[3][3] * alpha + m_matrix[3][4]; |
| } |
| |
| } // namespace WebCore |