layout/base/nsCSSColorUtils.cpp@b8a032363ba2
layout/base/nsCSSColorUtils.cpp
Thu, 22 Jan 2015 13:21:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 22 Jan 2015 13:21:57 +0100
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
- permissions
- -rw-r--r--
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 /* functions that manipulate colors */
8 #include "nsCSSColorUtils.h"
9 #include "nsDebug.h"
10 #include <math.h>
12 // Weird color computing code stolen from winfe which was stolen
13 // from the xfe which was written originally by Eric Bina. So there.
15 #define RED_LUMINOSITY 299
16 #define GREEN_LUMINOSITY 587
17 #define BLUE_LUMINOSITY 114
18 #define INTENSITY_FACTOR 25
19 #define LUMINOSITY_FACTOR 75
21 #define MAX_COLOR 255
22 #define COLOR_DARK_THRESHOLD 51
23 #define COLOR_LIGHT_THRESHOLD 204
25 #define COLOR_LITE_BS_FACTOR 45
26 #define COLOR_LITE_TS_FACTOR 70
28 #define COLOR_DARK_BS_FACTOR 30
29 #define COLOR_DARK_TS_FACTOR 50
31 #define LIGHT_GRAY NS_RGB(192, 192, 192)
32 #define DARK_GRAY NS_RGB(96, 96, 96)
34 #define MAX_BRIGHTNESS 254
35 #define MAX_DARKNESS 0
37 void NS_GetSpecial3DColors(nscolor aResult[2],
38 nscolor aBackgroundColor,
39 nscolor aBorderColor)
40 {
42 uint8_t f0, f1;
43 uint8_t r, g, b;
45 uint8_t rb = NS_GET_R(aBorderColor);
46 uint8_t gb = NS_GET_G(aBorderColor);
47 uint8_t bb = NS_GET_B(aBorderColor);
49 uint8_t a = NS_GET_A(aBorderColor);
51 // This needs to be optimized.
52 // Calculating background brightness again and again is
53 // a waste of time!!!. Just calculate it only once.
54 // .....somehow!!!
56 uint8_t red = NS_GET_R(aBackgroundColor);
57 uint8_t green = NS_GET_G(aBackgroundColor);
58 uint8_t blue = NS_GET_B(aBackgroundColor);
60 uint8_t elementBrightness = NS_GetBrightness(rb,gb,bb);
61 uint8_t backgroundBrightness = NS_GetBrightness(red, green, blue);
64 if (backgroundBrightness < COLOR_DARK_THRESHOLD) {
65 f0 = COLOR_DARK_BS_FACTOR;
66 f1 = COLOR_DARK_TS_FACTOR;
67 if(elementBrightness == MAX_DARKNESS)
68 {
69 rb = NS_GET_R(DARK_GRAY);
70 gb = NS_GET_G(DARK_GRAY);
71 bb = NS_GET_B(DARK_GRAY);
72 }
73 }else if (backgroundBrightness > COLOR_LIGHT_THRESHOLD) {
74 f0 = COLOR_LITE_BS_FACTOR;
75 f1 = COLOR_LITE_TS_FACTOR;
76 if(elementBrightness == MAX_BRIGHTNESS)
77 {
78 rb = NS_GET_R(LIGHT_GRAY);
79 gb = NS_GET_G(LIGHT_GRAY);
80 bb = NS_GET_B(LIGHT_GRAY);
81 }
82 }else {
83 f0 = COLOR_DARK_BS_FACTOR +
84 (backgroundBrightness *
85 (COLOR_LITE_BS_FACTOR - COLOR_DARK_BS_FACTOR) / MAX_COLOR);
86 f1 = COLOR_DARK_TS_FACTOR +
87 (backgroundBrightness *
88 (COLOR_LITE_TS_FACTOR - COLOR_DARK_TS_FACTOR) / MAX_COLOR);
89 }
92 r = rb - (f0 * rb / 100);
93 g = gb - (f0 * gb / 100);
94 b = bb - (f0 * bb / 100);
95 aResult[0] = NS_RGBA(r, g, b, a);
97 r = rb + (f1 * (MAX_COLOR - rb) / 100);
98 g = gb + (f1 * (MAX_COLOR - gb) / 100);
99 b = bb + (f1 * (MAX_COLOR - bb) / 100);
100 aResult[1] = NS_RGBA(r, g, b, a);
101 }
103 int NS_GetBrightness(uint8_t aRed, uint8_t aGreen, uint8_t aBlue)
104 {
106 uint8_t intensity = (aRed + aGreen + aBlue) / 3;
108 uint8_t luminosity = NS_GetLuminosity(NS_RGB(aRed, aGreen, aBlue)) / 1000;
110 return ((intensity * INTENSITY_FACTOR) +
111 (luminosity * LUMINOSITY_FACTOR)) / 100;
112 }
114 int32_t NS_GetLuminosity(nscolor aColor)
115 {
116 // When aColor is not opaque, the perceived luminosity will depend
117 // on what color(s) aColor is ultimately drawn on top of, which we
118 // do not know.
119 NS_ASSERTION(NS_GET_A(aColor) == 255,
120 "impossible to compute luminosity of a non-opaque color");
122 return (NS_GET_R(aColor) * RED_LUMINOSITY +
123 NS_GET_G(aColor) * GREEN_LUMINOSITY +
124 NS_GET_B(aColor) * BLUE_LUMINOSITY);
125 }
127 // Function to convert RGB color space into the HSV colorspace
128 // Hue is the primary color defined from 0 to 359 degrees
129 // Saturation is defined from 0 to 255. The higher the number.. the deeper
130 // the color Value is the brightness of the color. 0 is black, 255 is white.
131 void NS_RGB2HSV(nscolor aColor, uint16_t &aHue, uint16_t &aSat,
132 uint16_t &aValue, uint8_t &aAlpha)
133 {
134 uint8_t r, g, b;
135 int16_t delta, min, max, r1, b1, g1;
136 float hue;
138 r = NS_GET_R(aColor);
139 g = NS_GET_G(aColor);
140 b = NS_GET_B(aColor);
142 if (r>g) {
143 max = r;
144 min = g;
145 } else {
146 max = g;
147 min = r;
148 }
150 if (b>max) {
151 max = b;
152 }
153 if (b<min) {
154 min = b;
155 }
157 // value or brightness will always be the max of all the colors(RGB)
158 aValue = max;
159 delta = max-min;
160 aSat = (max!=0)?((delta*255)/max):0;
161 r1 = r;
162 b1 = b;
163 g1 = g;
165 if (aSat==0) {
166 hue = 1000;
167 } else {
168 if(r==max){
169 hue=(float)(g1-b1)/(float)delta;
170 } else if (g1==max) {
171 hue= 2.0f+(float)(b1-r1)/(float)delta;
172 } else {
173 hue = 4.0f+(float)(r1-g1)/(float)delta;
174 }
175 }
177 if(hue<999) {
178 hue*=60;
179 if(hue<0){
180 hue+=360;
181 }
182 } else {
183 hue=0;
184 }
186 aHue = (uint16_t)hue;
188 aAlpha = NS_GET_A(aColor);
189 }
191 // Function to convert HSV color space into the RGB colorspace
192 // Hue is the primary color defined from 0 to 359 degrees
193 // Saturation is defined from 0 to 255. The higher the number.. the deeper
194 // the color Value is the brightness of the color. 0 is black, 255 is white.
195 void NS_HSV2RGB(nscolor &aColor, uint16_t aHue, uint16_t aSat, uint16_t aValue,
196 uint8_t aAlpha)
197 {
198 uint16_t r = 0, g = 0, b = 0;
199 uint16_t i, p, q, t;
200 double h, f, percent;
202 if ( aSat == 0 ){
203 // achromatic color, no hue is defined
204 r = aValue;
205 g = aValue;
206 b = aValue;
207 } else {
208 // hue in in degrees around the color wheel defined from
209 // 0 to 360 degrees.
210 if (aHue >= 360) {
211 aHue = 0;
212 }
214 // we break the color wheel into 6 areas.. these
215 // areas define how the saturation and value define the color.
216 // reds behave differently than the blues
217 h = (double)aHue / 60.0;
218 i = (uint16_t) floor(h);
219 f = h-(double)i;
220 percent = ((double)aValue/255.0); // this needs to be a value from 0 to 1, so a percentage
221 // can be calculated of the saturation.
222 p = (uint16_t)(percent*(255-aSat));
223 q = (uint16_t)(percent*(255-(aSat*f)));
224 t = (uint16_t)(percent*(255-(aSat*(1.0-f))));
226 // i is guaranteed to never be larger than 5.
227 switch(i){
228 case 0: r = aValue; g = t; b = p;break;
229 case 1: r = q; g = aValue; b = p;break;
230 case 2: r = p; g = aValue; b = t;break;
231 case 3: r = p; g = q; b = aValue;break;
232 case 4: r = t; g = p; b = aValue;break;
233 case 5: r = aValue; g = p; b = q;break;
234 }
235 }
236 aColor = NS_RGBA(r, g, b, aAlpha);
237 }
239 #undef RED_LUMINOSITY
240 #undef GREEN_LUMINOSITY
241 #undef BLUE_LUMINOSITY
242 #undef INTENSITY_FACTOR
243 #undef LUMINOSITY_FACTOR
245 #undef MAX_COLOR
246 #undef COLOR_DARK_THRESHOLD
247 #undef COLOR_LIGHT_THRESHOLD
249 #undef COLOR_LITE_BS_FACTOR
250 #undef COLOR_LITE_TS_FACTOR
252 #undef COLOR_DARK_BS_FACTOR
253 #undef COLOR_DARK_TS_FACTOR
255 #undef LIGHT_GRAY
256 #undef DARK_GRAY
258 #undef MAX_BRIGHTNESS
259 #undef MAX_DARKNESS
