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Diffstat (limited to 'layout/base/nsCSSColorUtils.cpp')
| -rw-r--r-- | layout/base/nsCSSColorUtils.cpp | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/layout/base/nsCSSColorUtils.cpp b/layout/base/nsCSSColorUtils.cpp new file mode 100644 index 0000000000..66e6a333ba --- /dev/null +++ b/layout/base/nsCSSColorUtils.cpp @@ -0,0 +1,202 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* functions that manipulate colors */ + +#include "nsCSSColorUtils.h" +#include "nsDebug.h" +#include <math.h> + +// Weird color computing code stolen from winfe which was stolen +// from the xfe which was written originally by Eric Bina. So there. + +#define RED_LUMINOSITY 299 +#define GREEN_LUMINOSITY 587 +#define BLUE_LUMINOSITY 114 +#define INTENSITY_FACTOR 25 +#define LUMINOSITY_FACTOR 75 + +void NS_GetSpecial3DColors(nscolor aResult[2], nscolor aBorderColor) { + const float kDarkerScale = 2.0f / 3.0f; + + uint8_t r = NS_GET_R(aBorderColor); + uint8_t g = NS_GET_G(aBorderColor); + uint8_t b = NS_GET_B(aBorderColor); + uint8_t a = NS_GET_A(aBorderColor); + if (r == 0 && g == 0 && b == 0) { + // 0.3 * black + aResult[0] = NS_RGBA(76, 76, 76, a); + // 0.7 * black + aResult[1] = NS_RGBA(178, 178, 178, a); + return; + } + + aResult[0] = NS_RGBA(uint8_t(r * kDarkerScale), uint8_t(g * kDarkerScale), + uint8_t(b * kDarkerScale), a); + aResult[1] = aBorderColor; +} + +int NS_GetBrightness(uint8_t aRed, uint8_t aGreen, uint8_t aBlue) { + uint8_t intensity = (aRed + aGreen + aBlue) / 3; + + uint8_t luminosity = NS_GetLuminosity(NS_RGB(aRed, aGreen, aBlue)) / 1000; + + return ((intensity * INTENSITY_FACTOR) + (luminosity * LUMINOSITY_FACTOR)) / + 100; +} + +int32_t NS_GetLuminosity(nscolor aColor) { + // When aColor is not opaque, the perceived luminosity will depend + // on what color(s) aColor is ultimately drawn on top of, which we + // do not know. + NS_ASSERTION(NS_GET_A(aColor) == 255, + "impossible to compute luminosity of a non-opaque color"); + + return (NS_GET_R(aColor) * RED_LUMINOSITY + + NS_GET_G(aColor) * GREEN_LUMINOSITY + + NS_GET_B(aColor) * BLUE_LUMINOSITY); +} + +// Function to convert RGB color space into the HSV colorspace +// Hue is the primary color defined from 0 to 359 degrees +// Saturation is defined from 0 to 255. The higher the number.. the deeper +// the color Value is the brightness of the color. 0 is black, 255 is white. +void NS_RGB2HSV(nscolor aColor, uint16_t& aHue, uint16_t& aSat, + uint16_t& aValue, uint8_t& aAlpha) { + uint8_t r, g, b; + int16_t delta, min, max, r1, b1, g1; + float hue; + + r = NS_GET_R(aColor); + g = NS_GET_G(aColor); + b = NS_GET_B(aColor); + + if (r > g) { + max = r; + min = g; + } else { + max = g; + min = r; + } + + if (b > max) { + max = b; + } + if (b < min) { + min = b; + } + + // value or brightness will always be the max of all the colors(RGB) + aValue = max; + delta = max - min; + aSat = (max != 0) ? ((delta * 255) / max) : 0; + r1 = r; + b1 = b; + g1 = g; + + if (aSat == 0) { + hue = 1000; + } else { + if (r == max) { + hue = (float)(g1 - b1) / (float)delta; + } else if (g1 == max) { + hue = 2.0f + (float)(b1 - r1) / (float)delta; + } else { + hue = 4.0f + (float)(r1 - g1) / (float)delta; + } + } + + if (hue < 999) { + hue *= 60; + if (hue < 0) { + hue += 360; + } + } else { + hue = 0; + } + + aHue = (uint16_t)hue; + + aAlpha = NS_GET_A(aColor); +} + +// Function to convert HSV color space into the RGB colorspace +// Hue is the primary color defined from 0 to 359 degrees +// Saturation is defined from 0 to 255. The higher the number.. the deeper +// the color Value is the brightness of the color. 0 is black, 255 is white. +void NS_HSV2RGB(nscolor& aColor, uint16_t aHue, uint16_t aSat, uint16_t aValue, + uint8_t aAlpha) { + uint16_t r = 0, g = 0, b = 0; + uint16_t i, p, q, t; + double h, f, percent; + + if (aSat == 0) { + // achromatic color, no hue is defined + r = aValue; + g = aValue; + b = aValue; + } else { + // hue in in degrees around the color wheel defined from + // 0 to 360 degrees. + if (aHue >= 360) { + aHue = 0; + } + + // we break the color wheel into 6 areas.. these + // areas define how the saturation and value define the color. + // reds behave differently than the blues + h = (double)aHue / 60.0; + i = (uint16_t)floor(h); + f = h - (double)i; + percent = ((double)aValue / + 255.0); // this needs to be a value from 0 to 1, so a percentage + // can be calculated of the saturation. + p = (uint16_t)(percent * (255 - aSat)); + q = (uint16_t)(percent * (255 - (aSat * f))); + t = (uint16_t)(percent * (255 - (aSat * (1.0 - f)))); + + // i is guaranteed to never be larger than 5. + switch (i) { + case 0: + r = aValue; + g = t; + b = p; + break; + case 1: + r = q; + g = aValue; + b = p; + break; + case 2: + r = p; + g = aValue; + b = t; + break; + case 3: + r = p; + g = q; + b = aValue; + break; + case 4: + r = t; + g = p; + b = aValue; + break; + case 5: + r = aValue; + g = p; + b = q; + break; + } + } + aColor = NS_RGBA(r, g, b, aAlpha); +} + +#undef RED_LUMINOSITY +#undef GREEN_LUMINOSITY +#undef BLUE_LUMINOSITY +#undef INTENSITY_FACTOR +#undef LUMINOSITY_FACTOR |