Index: gfx/color_utils.cc |
=================================================================== |
--- gfx/color_utils.cc (revision 73487) |
+++ gfx/color_utils.cc (working copy) |
@@ -1,300 +0,0 @@ |
-// Copyright (c) 2010 The Chromium Authors. All rights reserved. |
-// Use of this source code is governed by a BSD-style license that can be |
-// found in the LICENSE file. |
- |
-#include "gfx/color_utils.h" |
- |
-#include <math.h> |
-#if defined(OS_WIN) |
-#include <windows.h> |
-#endif |
- |
-#include <algorithm> |
- |
-#include "base/basictypes.h" |
-#include "base/logging.h" |
-#include "build/build_config.h" |
-#if defined(OS_WIN) |
-#include "skia/ext/skia_utils_win.h" |
-#endif |
-#include "third_party/skia/include/core/SkBitmap.h" |
- |
-namespace color_utils { |
- |
-// Helper functions ----------------------------------------------------------- |
- |
-namespace { |
- |
-double calcHue(double temp1, double temp2, double hue) { |
- if (hue < 0.0) |
- ++hue; |
- else if (hue > 1.0) |
- --hue; |
- |
- if (hue * 6.0 < 1.0) |
- return temp1 + (temp2 - temp1) * hue * 6.0; |
- if (hue * 2.0 < 1.0) |
- return temp2; |
- if (hue * 3.0 < 2.0) |
- return temp1 + (temp2 - temp1) * (2.0 / 3.0 - hue) * 6.0; |
- |
- return temp1; |
-} |
- |
-int GetLumaForColor(SkColor* color) { |
- int luma = static_cast<int>((0.3 * SkColorGetR(*color)) + |
- (0.59 * SkColorGetG(*color)) + |
- (0.11 * SkColorGetB(*color))); |
- return std::max(std::min(luma, 255), 0); |
-} |
- |
-// Next two functions' formulas from: |
-// http://www.w3.org/TR/WCAG20/#relativeluminancedef |
-// http://www.w3.org/TR/WCAG20/#contrast-ratiodef |
- |
-double ConvertSRGB(double eight_bit_component) { |
- const double component = eight_bit_component / 255.0; |
- return (component <= 0.03928) ? |
- (component / 12.92) : pow((component + 0.055) / 1.055, 2.4); |
-} |
- |
-SkColor LumaInvertColor(const SkColor& color) { |
- HSL hsl; |
- SkColorToHSL(color, &hsl); |
- hsl.l = 1.0 - hsl.l; |
- return HSLToSkColor(hsl, 255); |
-} |
- |
-double ContrastRatio(double foreground_luminance, double background_luminance) { |
- // NOTE: Only pass in numbers obtained from RelativeLuminance(), since those |
- // are guaranteed to be > 0 and thus not cause a divide-by-zero error here. |
- return (foreground_luminance > background_luminance) ? |
- (foreground_luminance / background_luminance) : |
- (background_luminance / foreground_luminance); |
-} |
- |
-} // namespace |
- |
-// ---------------------------------------------------------------------------- |
- |
-double RelativeLuminance(SkColor color) { |
- return (0.2126 * ConvertSRGB(SkColorGetR(color))) + |
- (0.7152 * ConvertSRGB(SkColorGetG(color))) + |
- (0.0722 * ConvertSRGB(SkColorGetB(color))) + 0.05; |
-} |
- |
-void SkColorToHSL(SkColor c, HSL* hsl) { |
- double r = static_cast<double>(SkColorGetR(c)) / 255.0; |
- double g = static_cast<double>(SkColorGetG(c)) / 255.0; |
- double b = static_cast<double>(SkColorGetB(c)) / 255.0; |
- double vmax = std::max(std::max(r, g), b); |
- double vmin = std::min(std::min(r, g), b); |
- double delta = vmax - vmin; |
- hsl->l = (vmax + vmin) / 2; |
- if (delta) { |
- double dr = (((vmax - r) / 6.0) + (delta / 2.0)) / delta; |
- double dg = (((vmax - g) / 6.0) + (delta / 2.0)) / delta; |
- double db = (((vmax - b) / 6.0) + (delta / 2.0)) / delta; |
- // We need to compare for the max value because comparing vmax to r, |
- // g or b can sometimes result in values overflowing registers. |
- if (r >= g && r >= b) |
- hsl->h = db - dg; |
- else if (g >= r && g >= b) |
- hsl->h = (1.0 / 3.0) + dr - db; |
- else // (b >= r && b >= g) |
- hsl->h = (2.0 / 3.0) + dg - dr; |
- |
- if (hsl->h < 0.0) |
- ++hsl->h; |
- else if (hsl->h > 1.0) |
- --hsl->h; |
- |
- hsl->s = delta / ((hsl->l < 0.5) ? (vmax + vmin) : (2 - vmax - vmin)); |
- } else { |
- hsl->h = hsl->s = 0; |
- } |
-} |
- |
-SkColor HSLToSkColor(const HSL& hsl, SkAlpha alpha) { |
- double hue = hsl.h; |
- double saturation = hsl.s; |
- double lightness = hsl.l; |
- |
- // If there's no color, we don't care about hue and can do everything based |
- // on brightness. |
- if (!saturation) { |
- uint8 light; |
- |
- if (lightness < 0) |
- light = 0; |
- else if (lightness >= 1.0) |
- light = 255; |
- else |
- light = SkDoubleToFixed(lightness) >> 8; |
- |
- return SkColorSetARGB(alpha, light, light, light); |
- } |
- |
- double temp2 = (lightness < 0.5) ? |
- (lightness * (1.0 + saturation)) : |
- (lightness + saturation - (lightness * saturation)); |
- double temp1 = 2.0 * lightness - temp2; |
- return SkColorSetARGB(alpha, |
- static_cast<int>(calcHue(temp1, temp2, hue + 1.0 / 3.0) * 255), |
- static_cast<int>(calcHue(temp1, temp2, hue) * 255), |
- static_cast<int>(calcHue(temp1, temp2, hue - 1.0 / 3.0) * 255)); |
-} |
- |
-SkColor HSLShift(SkColor color, const HSL& shift) { |
- HSL hsl; |
- int alpha = SkColorGetA(color); |
- SkColorToHSL(color, &hsl); |
- |
- // Replace the hue with the tint's hue. |
- if (shift.h >= 0) |
- hsl.h = shift.h; |
- |
- // Change the saturation. |
- if (shift.s >= 0) { |
- if (shift.s <= 0.5) |
- hsl.s *= shift.s * 2.0; |
- else |
- hsl.s += (1.0 - hsl.s) * ((shift.s - 0.5) * 2.0); |
- } |
- |
- SkColor result = HSLToSkColor(hsl, alpha); |
- |
- if (shift.l < 0) |
- return result; |
- |
- // Lightness shifts in the style of popular image editors aren't |
- // actually represented in HSL - the L value does have some effect |
- // on saturation. |
- double r = static_cast<double>(SkColorGetR(result)); |
- double g = static_cast<double>(SkColorGetG(result)); |
- double b = static_cast<double>(SkColorGetB(result)); |
- if (shift.l <= 0.5) { |
- r *= (shift.l * 2.0); |
- g *= (shift.l * 2.0); |
- b *= (shift.l * 2.0); |
- } else { |
- r += (255.0 - r) * ((shift.l - 0.5) * 2.0); |
- g += (255.0 - g) * ((shift.l - 0.5) * 2.0); |
- b += (255.0 - b) * ((shift.l - 0.5) * 2.0); |
- } |
- return SkColorSetARGB(alpha, |
- static_cast<int>(r), |
- static_cast<int>(g), |
- static_cast<int>(b)); |
-} |
- |
-bool IsColorCloseToTransparent(SkAlpha alpha) { |
- const int kCloseToBoundary = 64; |
- return alpha < kCloseToBoundary; |
-} |
- |
-bool IsColorCloseToGrey(int r, int g, int b) { |
- const int kAverageBoundary = 15; |
- int average = (r + g + b) / 3; |
- return (abs(r - average) < kAverageBoundary) && |
- (abs(g - average) < kAverageBoundary) && |
- (abs(b - average) < kAverageBoundary); |
-} |
- |
-SkColor GetAverageColorOfFavicon(SkBitmap* favicon, SkAlpha alpha) { |
- int r = 0, g = 0, b = 0; |
- |
- SkAutoLockPixels favicon_lock(*favicon); |
- SkColor* pixels = static_cast<SkColor*>(favicon->getPixels()); |
- // Assume ARGB_8888 format. |
- DCHECK(favicon->getConfig() == SkBitmap::kARGB_8888_Config); |
- SkColor* current_color = pixels; |
- |
- DCHECK(favicon->width() <= 16 && favicon->height() <= 16); |
- |
- int pixel_count = favicon->width() * favicon->height(); |
- int color_count = 0; |
- for (int i = 0; i < pixel_count; ++i, ++current_color) { |
- // Disregard this color if it is close to black, close to white, or close |
- // to transparent since any of those pixels do not contribute much to the |
- // color makeup of this icon. |
- int cr = SkColorGetR(*current_color); |
- int cg = SkColorGetG(*current_color); |
- int cb = SkColorGetB(*current_color); |
- |
- if (IsColorCloseToTransparent(SkColorGetA(*current_color)) || |
- IsColorCloseToGrey(cr, cg, cb)) |
- continue; |
- |
- r += cr; |
- g += cg; |
- b += cb; |
- ++color_count; |
- } |
- |
- return color_count ? |
- SkColorSetARGB(alpha, r / color_count, g / color_count, b / color_count) : |
- SkColorSetARGB(alpha, 0, 0, 0); |
-} |
- |
-void BuildLumaHistogram(SkBitmap* bitmap, int histogram[256]) { |
- SkAutoLockPixels bitmap_lock(*bitmap); |
- // Assume ARGB_8888 format. |
- DCHECK(bitmap->getConfig() == SkBitmap::kARGB_8888_Config); |
- |
- int pixel_width = bitmap->width(); |
- int pixel_height = bitmap->height(); |
- for (int y = 0; y < pixel_height; ++y) { |
- SkColor* current_color = static_cast<uint32_t*>(bitmap->getAddr32(0, y)); |
- for (int x = 0; x < pixel_width; ++x, ++current_color) |
- histogram[GetLumaForColor(current_color)]++; |
- } |
-} |
- |
-SkColor AlphaBlend(SkColor foreground, SkColor background, SkAlpha alpha) { |
- if (alpha == 0) |
- return background; |
- if (alpha == 255) |
- return foreground; |
- |
- int f_alpha = SkColorGetA(foreground); |
- int b_alpha = SkColorGetA(background); |
- |
- double normalizer = (f_alpha * alpha + b_alpha * (255 - alpha)) / 255.0; |
- if (normalizer == 0.0) |
- return SkColorSetARGB(0, 0, 0, 0); |
- |
- double f_weight = f_alpha * alpha / normalizer; |
- double b_weight = b_alpha * (255 - alpha) / normalizer; |
- |
- double r = (SkColorGetR(foreground) * f_weight + |
- SkColorGetR(background) * b_weight) / 255.0; |
- double g = (SkColorGetG(foreground) * f_weight + |
- SkColorGetG(background) * b_weight) / 255.0; |
- double b = (SkColorGetB(foreground) * f_weight + |
- SkColorGetB(background) * b_weight) / 255.0; |
- |
- return SkColorSetARGB(static_cast<int>(normalizer), |
- static_cast<int>(r), |
- static_cast<int>(g), |
- static_cast<int>(b)); |
-} |
- |
-SkColor GetReadableColor(SkColor foreground, SkColor background) { |
- const SkColor foreground2 = LumaInvertColor(foreground); |
- const double background_luminance = RelativeLuminance(background); |
- return (ContrastRatio(RelativeLuminance(foreground), background_luminance) >= |
- ContrastRatio(RelativeLuminance(foreground2), background_luminance)) ? |
- foreground : foreground2; |
-} |
- |
-SkColor GetSysSkColor(int which) { |
-#if defined(OS_WIN) |
- return skia::COLORREFToSkColor(GetSysColor(which)); |
-#else |
- NOTIMPLEMENTED(); |
- return SK_ColorLTGRAY; |
-#endif |
-} |
- |
-} // namespace color_utils |