1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
|
/* css3_color.c -- Routines for handling css3 colors
*
* Copyright (c) 1994-2018 Carnegie Mellon University. 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.
*
* 3. The name "Carnegie Mellon University" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For permission or any legal
* details, please contact
* Carnegie Mellon University
* Center for Technology Transfer and Enterprise Creation
* 4615 Forbes Avenue
* Suite 302
* Pittsburgh, PA 15213
* (412) 268-7393, fax: (412) 268-7395
* innovation@andrew.cmu.edu
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Computing Services
* at Carnegie Mellon University (http://www.cmu.edu/computing/)."
*
* CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
struct css3_color_t {
const char *name;
unsigned char r;
unsigned char g;
unsigned char b;
};
static const struct css3_color_t css3_colors[] = {
{ "aliceblue", 240, 248, 255 },
{ "antiquewhite", 250, 235, 215 },
{ "aqua", 0, 255, 255 },
{ "aquamarine", 127, 255, 212 },
{ "azure", 240, 255, 255 },
{ "beige", 245, 245, 220 },
{ "bisque", 255, 228, 196 },
{ "black", 0, 0, 0 },
{ "blanchedalmond", 255, 235, 205 },
{ "blue", 0, 0, 255 },
{ "blueviolet", 138, 43, 226 },
{ "brown", 165, 42, 42 },
{ "burlywood", 222, 184, 135 },
{ "cadetblue", 95, 158, 160 },
{ "chartreuse", 127, 255, 0 },
{ "chocolate", 210, 105, 30 },
{ "coral", 255, 127, 80 },
{ "cornflowerblue", 100, 149, 237 },
{ "cornsilk", 255, 248, 220 },
{ "crimson", 220, 20, 60 },
{ "cyan", 0, 255, 255 },
{ "darkblue", 0, 0, 139 },
{ "darkcyan", 0, 139, 139 },
{ "darkgoldenrod", 184, 134, 11 },
{ "darkgray", 169, 169, 169 },
{ "darkgreen", 0, 100, 0 },
{ "darkgrey", 169, 169, 169 },
{ "darkkhaki", 189, 183, 107 },
{ "darkmagenta", 139, 0, 139 },
{ "darkolivegreen", 85, 107, 47 },
{ "darkorange", 255, 140, 0 },
{ "darkorchid", 153, 50, 204 },
{ "darkred", 139, 0, 0 },
{ "darksalmon", 233, 150, 122 },
{ "darkseagreen", 143, 188, 143 },
{ "darkslateblue", 72 , 61, 139 },
{ "darkslategray", 47, 79, 79 },
{ "darkslategrey", 47, 79, 79 },
{ "darkturquoise", 0, 206, 209 },
{ "darkviolet", 148, 0, 211 },
{ "deeppink", 255, 20, 147 },
{ "deepskyblue", 0, 191, 255 },
{ "dimgray", 105, 105, 105 },
{ "dimgrey", 105, 105, 105 },
{ "dodgerblue", 30, 144, 255 },
{ "firebrick", 178, 34, 34 },
{ "floralwhite", 255, 250, 240 },
{ "forestgreen", 34, 139, 34 },
{ "fuchsia", 255, 0, 255 },
{ "gainsboro", 220, 220, 220 },
{ "ghostwhite", 248, 248, 255 },
{ "gold", 255, 215, 0 },
{ "goldenrod", 218, 165, 32 },
{ "gray", 128, 128, 128 },
{ "green", 0, 128, 0 },
{ "greenyellow", 173, 255, 47 },
{ "grey", 128, 128, 128 },
{ "honeydew", 240, 255, 240 },
{ "hotpink", 255, 105, 180 },
{ "indianred", 205, 92, 92 },
{ "indigo", 75, 0, 130 },
{ "ivory", 255, 255, 240 },
{ "khaki", 240, 230, 140 },
{ "lavender", 230, 230, 250 },
{ "lavenderblush", 255, 240, 245 },
{ "lawngreen", 124, 252, 0 },
{ "lemonchiffon", 255, 250, 205 },
{ "lightblue", 173, 216, 230 },
{ "lightcoral", 240, 128, 128 },
{ "lightcyan", 224, 255, 255 },
{ "lightgoldenrodyellow", 250, 250, 210 },
{ "lightgray", 211, 211, 211 },
{ "lightgreen", 144, 238, 144 },
{ "lightgrey", 211, 211, 211 },
{ "lightpink", 255, 182, 193 },
{ "lightsalmon", 255, 160, 122 },
{ "lightseagreen", 32, 178, 170 },
{ "lightskyblue", 135, 206, 250 },
{ "lightslategray", 119, 136, 153 },
{ "lightslategrey", 119, 136, 153 },
{ "lightsteelblue", 176, 196, 222 },
{ "lightyellow", 255, 255, 224 },
{ "lime", 0, 255, 0 },
{ "limegreen", 50, 205, 50 },
{ "linen", 250, 240, 230 },
{ "magenta", 255, 0, 255 },
{ "maroon", 128, 0, 0 },
{ "mediumaquamarine", 102, 205, 170 },
{ "mediumblue", 0, 0, 205 },
{ "mediumorchid", 186, 85, 211 },
{ "mediumpurple", 147, 112, 219 },
{ "mediumseagreen", 60, 179, 113 },
{ "mediumslateblue", 123, 104, 238 },
{ "mediumspringgreen", 0, 250, 154 },
{ "mediumturquoise", 72, 209, 204 },
{ "mediumvioletred", 199, 21, 133 },
{ "midnightblue", 25, 25, 112 },
{ "mintcream", 245, 255, 250 },
{ "mistyrose", 255, 228, 225 },
{ "moccasin", 255, 228, 181 },
{ "navajowhite", 255, 222, 173 },
{ "navy", 0, 0, 128 },
{ "oldlace", 253, 245, 230 },
{ "olive", 128, 128, 0 },
{ "olivedrab", 107, 142, 35 },
{ "orange", 255, 165, 0 },
{ "orangered", 255, 69, 0 },
{ "orchid", 218, 112, 214 },
{ "palegoldenrod", 238, 232, 170 },
{ "palegreen", 152, 251, 152 },
{ "paleturquoise", 175, 238, 238 },
{ "palevioletred", 219, 112, 147 },
{ "papayawhip", 255, 239, 213 },
{ "peachpuff", 255, 218, 185 },
{ "peru", 205, 133, 63 },
{ "pink", 255, 192, 203 },
{ "plum", 221, 160, 221 },
{ "powderblue", 176, 224, 230 },
{ "purple", 128, 0, 128 },
{ "red", 255, 0, 0 },
{ "rosybrown", 188, 143, 143 },
{ "royalblue", 65, 105, 225 },
{ "saddlebrown", 139, 69, 19 },
{ "salmon", 250, 128, 114 },
{ "sandybrown", 244, 164, 96 },
{ "seagreen", 46, 139, 87 },
{ "seashell", 255, 245, 238 },
{ "sienna", 160, 82, 45 },
{ "silver", 192, 192, 192 },
{ "skyblue", 135, 206, 235 },
{ "slateblue", 106, 90, 205 },
{ "slategray", 112, 128, 144 },
{ "slategrey", 112, 128, 144 },
{ "snow", 255, 250, 250 },
{ "springgreen", 0, 255, 127 },
{ "steelblue", 70, 130, 180 },
{ "tan", 210, 180, 140 },
{ "teal", 0, 128, 128 },
{ "thistle", 216, 191, 216 },
{ "tomato", 255, 99, 71 },
{ "turquoise", 64, 224, 208 },
{ "violet", 238, 130, 238 },
{ "wheat", 245, 222, 179 },
{ "white", 255, 255, 255 },
{ "whitesmoke", 245, 245, 245 },
{ "yellow", 255, 255, 0 },
{ "yellowgreen", 154, 205, 50 },
{ NULL, 0, 0, 0 }
};
/* Take a hex value for a color and find best matching css3 color name using:
https://en.wikipedia.org/wiki/Color_difference */
const char *css3_color_hex_to_name(const char *hexstr)
{
if (!hexstr || hexstr[0] != '#') return NULL;
size_t hexlen = strlen(hexstr);
if (hexlen != 7 && hexlen != 9) return NULL;
/* Convert hex encoded color into separate RGB */
long hex = strtol(hexstr+1, NULL, 16);
if (hexlen == 9) hex >>= 8; /* drop last 2 digits */
struct {
unsigned char r, g, b;
} C;
C.b = (hex & 0x0000ff);
hex >>= 8;
C.g = (hex & 0x00ff);
hex >>= 8;
C.r = (hex & 0xff);
const struct css3_color_t *css;
unsigned long best = ULONG_MAX;
const char *name = NULL;
for (css = css3_colors; css->name; css++) {
int dR = css->r - C.r;
int dG = css->g - C.g;
int dB = css->b - C.b;
if (dR == 0 && dG == 0 && dB == 0) return css->name;
unsigned dR2 = dR * dR;
unsigned dG2 = dG * dG;
unsigned dB2 = dB * dB;
unsigned long dC = 2*dR2 + 4*dG2 + 3*dB2;
unsigned r = (css->r + C.r) / 2;
dC += (r * (dR2 - dB2)) / 256;
if (dC < best) {
best = dC;
name = css->name;
}
}
return name;
}
|
