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29 #include "HashTools.h"
30 #include <wtf/Assertions.h>
31 #include <wtf/HexNumber.h>
32 #include <wtf/MathExtras.h>
33 #include <wtf/text/StringBuilder.h>
40 const RGBA32 Color::black;
41 const RGBA32 Color::white;
42 const RGBA32 Color::darkGray;
43 const RGBA32 Color::gray;
44 const RGBA32 Color::lightGray;
45 const RGBA32 Color::transparent;
48 static const RGBA32 lightenedBlack = 0xFF545454;
49 static const RGBA32 darkenedWhite = 0xFFABABAB;
51 RGBA32 makeRGB(int r, int g, int b)
53 return 0xFF000000 | max(0, min(r, 255)) << 16 | max(0, min(g, 255)) << 8 | max(0, min(b, 255));
56 RGBA32 makeRGBA(int r, int g, int b, int a)
58 return max(0, min(a, 255)) << 24 | max(0, min(r, 255)) << 16 | max(0, min(g, 255)) << 8 | max(0, min(b, 255));
61 static int colorFloatToRGBAByte(float f)
63 // We use lroundf and 255 instead of nextafterf(256, 0) to match CG's rounding
64 return max(0, min(static_cast<int>(lroundf(255.0f * f)), 255));
67 RGBA32 makeRGBA32FromFloats(float r, float g, float b, float a)
69 return colorFloatToRGBAByte(a) << 24 | colorFloatToRGBAByte(r) << 16 | colorFloatToRGBAByte(g) << 8 | colorFloatToRGBAByte(b);
72 RGBA32 colorWithOverrideAlpha(RGBA32 color, float overrideAlpha)
74 RGBA32 rgbOnly = color & 0x00FFFFFF;
75 RGBA32 rgba = rgbOnly | colorFloatToRGBAByte(overrideAlpha) << 24;
79 static double calcHue(double temp1, double temp2, double hueVal)
83 else if (hueVal > 1.0)
85 if (hueVal * 6.0 < 1.0)
86 return temp1 + (temp2 - temp1) * hueVal * 6.0;
87 if (hueVal * 2.0 < 1.0)
89 if (hueVal * 3.0 < 2.0)
90 return temp1 + (temp2 - temp1) * (2.0 / 3.0 - hueVal) * 6.0;
94 // Explanation of this algorithm can be found in the CSS3 Color Module
95 // specification at http://www.w3.org/TR/css3-color/#hsl-color with further
96 // explanation available at http://en.wikipedia.org/wiki/HSL_color_space
98 // all values are in the range of 0 to 1.0
99 RGBA32 makeRGBAFromHSLA(double hue, double saturation, double lightness, double alpha)
101 const double scaleFactor = nextafter(256.0, 0.0);
104 int greyValue = static_cast<int>(lightness * scaleFactor);
105 return makeRGBA(greyValue, greyValue, greyValue, static_cast<int>(alpha * scaleFactor));
108 double temp2 = lightness < 0.5 ? lightness * (1.0 + saturation) : lightness + saturation - lightness * saturation;
109 double temp1 = 2.0 * lightness - temp2;
111 return makeRGBA(static_cast<int>(calcHue(temp1, temp2, hue + 1.0 / 3.0) * scaleFactor),
112 static_cast<int>(calcHue(temp1, temp2, hue) * scaleFactor),
113 static_cast<int>(calcHue(temp1, temp2, hue - 1.0 / 3.0) * scaleFactor),
114 static_cast<int>(alpha * scaleFactor));
117 RGBA32 makeRGBAFromCMYKA(float c, float m, float y, float k, float a)
119 double colors = 1 - k;
120 int r = static_cast<int>(nextafter(256, 0) * (colors * (1 - c)));
121 int g = static_cast<int>(nextafter(256, 0) * (colors * (1 - m)));
122 int b = static_cast<int>(nextafter(256, 0) * (colors * (1 - y)));
123 return makeRGBA(r, g, b, static_cast<float>(nextafter(256, 0) * a));
126 // originally moved here from the CSS parser
127 bool Color::parseHexColor(const UChar* name, unsigned length, RGBA32& rgb)
129 if (length != 3 && length != 6)
132 for (unsigned i = 0; i < length; ++i) {
133 if (!isASCIIHexDigit(name[i]))
136 value |= toASCIIHexValue(name[i]);
139 rgb = 0xFF000000 | value;
142 // #abc converts to #aabbcc
144 | (value & 0xF00) << 12 | (value & 0xF00) << 8
145 | (value & 0xF0) << 8 | (value & 0xF0) << 4
146 | (value & 0xF) << 4 | (value & 0xF);
150 bool Color::parseHexColor(const String& name, RGBA32& rgb)
152 return parseHexColor(name.characters(), name.length(), rgb);
155 int differenceSquared(const Color& c1, const Color& c2)
157 int dR = c1.red() - c2.red();
158 int dG = c1.green() - c2.green();
159 int dB = c1.blue() - c2.blue();
160 return dR * dR + dG * dG + dB * dB;
163 Color::Color(const String& name)
166 m_valid = parseHexColor(name.characters() + 1, name.length() - 1, m_color);
171 Color::Color(const char* name)
174 m_valid = parseHexColor(&name[1], m_color);
176 const NamedColor* foundColor = findColor(name, strlen(name));
177 m_color = foundColor ? foundColor->ARGBValue : 0;
178 m_valid = foundColor;
182 String Color::serialized() const
184 DEFINE_STATIC_LOCAL(const String, commaSpace, (", "));
185 DEFINE_STATIC_LOCAL(const String, rgbaParen, ("rgba("));
186 DEFINE_STATIC_LOCAL(const String, zeroPointZero, ("0.0"));
189 StringBuilder builder;
190 builder.reserveCapacity(7);
192 appendByteAsHex(red(), builder, Lowercase);
193 appendByteAsHex(green(), builder, Lowercase);
194 appendByteAsHex(blue(), builder, Lowercase);
195 return builder.toString();
198 Vector<UChar> result;
199 result.reserveInitialCapacity(28);
201 append(result, rgbaParen);
202 appendNumber(result, red());
203 append(result, commaSpace);
204 appendNumber(result, green());
205 append(result, commaSpace);
206 appendNumber(result, blue());
207 append(result, commaSpace);
209 // Match Gecko ("0.0" for zero, 5 decimals for anything else)
211 append(result, zeroPointZero);
213 append(result, String::format("%.5f", alpha() / 255.0f));
216 return String::adopt(result);
219 String Color::nameForRenderTreeAsText() const
222 return String::format("#%02X%02X%02X%02X", red(), green(), blue(), alpha());
223 return String::format("#%02X%02X%02X", red(), green(), blue());
226 static inline const NamedColor* findNamedColor(const String& name)
228 char buffer[64]; // easily big enough for the longest color name
229 unsigned length = name.length();
230 if (length > sizeof(buffer) - 1)
232 for (unsigned i = 0; i < length; ++i) {
236 buffer[i] = toASCIILower(static_cast<char>(c));
238 buffer[length] = '\0';
239 return findColor(buffer, length);
242 void Color::setNamedColor(const String& name)
244 const NamedColor* foundColor = findNamedColor(name);
245 m_color = foundColor ? foundColor->ARGBValue : 0;
246 m_valid = foundColor;
249 Color Color::light() const
251 // Hardcode this common case for speed.
252 if (m_color == black)
253 return lightenedBlack;
255 const float scaleFactor = nextafterf(256.0f, 0.0f);
260 float v = max(r, max(g, b));
263 // Lightened black with alpha.
264 return Color(0x54, 0x54, 0x54, alpha());
266 float multiplier = min(1.0f, v + 0.33f) / v;
268 return Color(static_cast<int>(multiplier * r * scaleFactor),
269 static_cast<int>(multiplier * g * scaleFactor),
270 static_cast<int>(multiplier * b * scaleFactor),
274 Color Color::dark() const
276 // Hardcode this common case for speed.
277 if (m_color == white)
278 return darkenedWhite;
280 const float scaleFactor = nextafterf(256.0f, 0.0f);
285 float v = max(r, max(g, b));
286 float multiplier = max(0.0f, (v - 0.33f) / v);
288 return Color(static_cast<int>(multiplier * r * scaleFactor),
289 static_cast<int>(multiplier * g * scaleFactor),
290 static_cast<int>(multiplier * b * scaleFactor),
294 static int blendComponent(int c, int a)
297 float alpha = a / 255.0f;
298 int whiteBlend = 255 - a;
300 return static_cast<int>(c / alpha);
303 const int cStartAlpha = 153; // 60%
304 const int cEndAlpha = 204; // 80%;
305 const int cAlphaIncrement = 17; // Increments in between.
307 Color Color::blend(const Color& source) const
309 if (!alpha() || !source.hasAlpha())
315 int d = 255 * (alpha() + source.alpha()) - alpha() * source.alpha();
317 int r = (red() * alpha() * (255 - source.alpha()) + 255 * source.alpha() * source.red()) / d;
318 int g = (green() * alpha() * (255 - source.alpha()) + 255 * source.alpha() * source.green()) / d;
319 int b = (blue() * alpha() * (255 - source.alpha()) + 255 * source.alpha() * source.blue()) / d;
320 return Color(r, g, b, a);
323 Color Color::blendWithWhite() const
325 // If the color contains alpha already, we leave it alone.
330 for (int alpha = cStartAlpha; alpha <= cEndAlpha; alpha += cAlphaIncrement) {
331 // We have a solid color. Convert to an equivalent color that looks the same when blended with white
332 // at the current alpha. Try using less transparency if the numbers end up being negative.
333 int r = blendComponent(red(), alpha);
334 int g = blendComponent(green(), alpha);
335 int b = blendComponent(blue(), alpha);
337 newColor = Color(r, g, b, alpha);
339 if (r >= 0 && g >= 0 && b >= 0)
345 void Color::getRGBA(float& r, float& g, float& b, float& a) const
348 g = green() / 255.0f;
350 a = alpha() / 255.0f;
353 void Color::getRGBA(double& r, double& g, double& b, double& a) const
361 void Color::getHSL(double& hue, double& saturation, double& lightness) const
363 // http://en.wikipedia.org/wiki/HSL_color_space. This is a direct copy of
364 // the algorithm therein, although it's 360^o based and we end up wanting
365 // [0...1) based. It's clearer if we stick to 360^o until the end.
366 double r = static_cast<double>(red()) / 255.0;
367 double g = static_cast<double>(green()) / 255.0;
368 double b = static_cast<double>(blue()) / 255.0;
369 double max = std::max(std::max(r, g), b);
370 double min = std::min(std::min(r, g), b);
375 hue = (60.0 * ((g - b) / (max - min))) + 360.0;
377 hue = (60.0 * ((b - r) / (max - min))) + 120.0;
379 hue = (60.0 * ((r - g) / (max - min))) + 240.0;
384 // makeRGBAFromHSLA assumes that hue is in [0...1).
387 lightness = 0.5 * (max + min);
390 else if (lightness <= 0.5)
391 saturation = ((max - min) / (max + min));
393 saturation = ((max - min) / (2.0 - (max + min)));
396 Color colorFromPremultipliedARGB(unsigned pixelColor)
400 if (unsigned alpha = (pixelColor & 0xFF000000) >> 24) {
401 rgba = makeRGBA(((pixelColor & 0x00FF0000) >> 16) * 255 / alpha,
402 ((pixelColor & 0x0000FF00) >> 8) * 255 / alpha,
403 (pixelColor & 0x000000FF) * 255 / alpha,
411 unsigned premultipliedARGBFromColor(const Color& color)
415 if (unsigned alpha = color.alpha()) {
416 pixelColor = alpha << 24 |
417 ((color.red() * alpha + 254) / 255) << 16 |
418 ((color.green() * alpha + 254) / 255) << 8 |
419 ((color.blue() * alpha + 254) / 255);
421 pixelColor = color.rgb();
426 } // namespace WebCore