33b73f0d4c44ed9e51ab91dc1e3a285a3edcee5e
1 #define __SP_SVG_COLOR_C__
3 /**
4 * \file
5 * Reading \& writing of SVG/CSS colors.
6 */
7 /*
8 * Authors:
9 * Lauris Kaplinski <lauris@kaplinski.com>
10 *
11 * Copyright (C) 1999-2002 Lauris Kaplinski
12 *
13 * Released under GNU GPL, read the file 'COPYING' for more information
14 */
16 #ifdef HAVE_CONFIG_H
17 # include "config.h"
18 #endif
20 #include "svg-color.h"
21 #include <cassert>
22 #include <math.h>
23 #include <glib/gmem.h>
24 #include <glib/gmessages.h>
25 #include <glib/gstrfuncs.h>
26 #include <glib/ghash.h>
27 #include <glib/gutils.h>
28 #include <cstdio> // sprintf
29 #include "strneq.h"
30 using std::sprintf;
32 struct SPSVGColor {
33 unsigned long rgb;
34 char const *name;
35 };
37 /*
38 * These are the colors defined in the SVG standard
39 */
40 static SPSVGColor const sp_svg_color_named[] = {
41 { 0xF0F8FF, "aliceblue" },
42 { 0xFAEBD7, "antiquewhite" },
43 { 0x00FFFF, "aqua" },
44 { 0x7FFFD4, "aquamarine" },
45 { 0xF0FFFF, "azure" },
46 { 0xF5F5DC, "beige" },
47 { 0xFFE4C4, "bisque" },
48 { 0x000000, "black" },
49 { 0xFFEBCD, "blanchedalmond" },
50 { 0x0000FF, "blue" },
51 { 0x8A2BE2, "blueviolet" },
52 { 0xA52A2A, "brown" },
53 { 0xDEB887, "burlywood" },
54 { 0x5F9EA0, "cadetblue" },
55 { 0x7FFF00, "chartreuse" },
56 { 0xD2691E, "chocolate" },
57 { 0xFF7F50, "coral" },
58 { 0x6495ED, "cornflowerblue" },
59 { 0xFFF8DC, "cornsilk" },
60 { 0xDC143C, "crimson" },
61 { 0x00FFFF, "cyan" },
62 { 0x00008B, "darkblue" },
63 { 0x008B8B, "darkcyan" },
64 { 0xB8860B, "darkgoldenrod" },
65 { 0xA9A9A9, "darkgray" },
66 { 0x006400, "darkgreen" },
67 { 0xA9A9A9, "darkgrey" },
68 { 0xBDB76B, "darkkhaki" },
69 { 0x8B008B, "darkmagenta" },
70 { 0x556B2F, "darkolivegreen" },
71 { 0xFF8C00, "darkorange" },
72 { 0x9932CC, "darkorchid" },
73 { 0x8B0000, "darkred" },
74 { 0xE9967A, "darksalmon" },
75 { 0x8FBC8F, "darkseagreen" },
76 { 0x483D8B, "darkslateblue" },
77 { 0x2F4F4F, "darkslategray" },
78 { 0x2F4F4F, "darkslategrey" },
79 { 0x00CED1, "darkturquoise" },
80 { 0x9400D3, "darkviolet" },
81 { 0xFF1493, "deeppink" },
82 { 0x00BFFF, "deepskyblue" },
83 { 0x696969, "dimgray" },
84 { 0x696969, "dimgrey" },
85 { 0x1E90FF, "dodgerblue" },
86 { 0xB22222, "firebrick" },
87 { 0xFFFAF0, "floralwhite" },
88 { 0x228B22, "forestgreen" },
89 { 0xFF00FF, "fuchsia" },
90 { 0xDCDCDC, "gainsboro" },
91 { 0xF8F8FF, "ghostwhite" },
92 { 0xFFD700, "gold" },
93 { 0xDAA520, "goldenrod" },
94 { 0x808080, "gray" },
95 { 0x808080, "grey" },
96 { 0x008000, "green" },
97 { 0xADFF2F, "greenyellow" },
98 { 0xF0FFF0, "honeydew" },
99 { 0xFF69B4, "hotpink" },
100 { 0xCD5C5C, "indianred" },
101 { 0x4B0082, "indigo" },
102 { 0xFFFFF0, "ivory" },
103 { 0xF0E68C, "khaki" },
104 { 0xE6E6FA, "lavender" },
105 { 0xFFF0F5, "lavenderblush" },
106 { 0x7CFC00, "lawngreen" },
107 { 0xFFFACD, "lemonchiffon" },
108 { 0xADD8E6, "lightblue" },
109 { 0xF08080, "lightcoral" },
110 { 0xE0FFFF, "lightcyan" },
111 { 0xFAFAD2, "lightgoldenrodyellow" },
112 { 0xD3D3D3, "lightgray" },
113 { 0x90EE90, "lightgreen" },
114 { 0xD3D3D3, "lightgrey" },
115 { 0xFFB6C1, "lightpink" },
116 { 0xFFA07A, "lightsalmon" },
117 { 0x20B2AA, "lightseagreen" },
118 { 0x87CEFA, "lightskyblue" },
119 { 0x778899, "lightslategray" },
120 { 0x778899, "lightslategrey" },
121 { 0xB0C4DE, "lightsteelblue" },
122 { 0xFFFFE0, "lightyellow" },
123 { 0x00FF00, "lime" },
124 { 0x32CD32, "limegreen" },
125 { 0xFAF0E6, "linen" },
126 { 0xFF00FF, "magenta" },
127 { 0x800000, "maroon" },
128 { 0x66CDAA, "mediumaquamarine" },
129 { 0x0000CD, "mediumblue" },
130 { 0xBA55D3, "mediumorchid" },
131 { 0x9370DB, "mediumpurple" },
132 { 0x3CB371, "mediumseagreen" },
133 { 0x7B68EE, "mediumslateblue" },
134 { 0x00FA9A, "mediumspringgreen" },
135 { 0x48D1CC, "mediumturquoise" },
136 { 0xC71585, "mediumvioletred" },
137 { 0x191970, "midnightblue" },
138 { 0xF5FFFA, "mintcream" },
139 { 0xFFE4E1, "mistyrose" },
140 { 0xFFE4B5, "moccasin" },
141 { 0xFFDEAD, "navajowhite" },
142 { 0x000080, "navy" },
143 { 0xFDF5E6, "oldlace" },
144 { 0x808000, "olive" },
145 { 0x6B8E23, "olivedrab" },
146 { 0xFFA500, "orange" },
147 { 0xFF4500, "orangered" },
148 { 0xDA70D6, "orchid" },
149 { 0xEEE8AA, "palegoldenrod" },
150 { 0x98FB98, "palegreen" },
151 { 0xAFEEEE, "paleturquoise" },
152 { 0xDB7093, "palevioletred" },
153 { 0xFFEFD5, "papayawhip" },
154 { 0xFFDAB9, "peachpuff" },
155 { 0xCD853F, "peru" },
156 { 0xFFC0CB, "pink" },
157 { 0xDDA0DD, "plum" },
158 { 0xB0E0E6, "powderblue" },
159 { 0x800080, "purple" },
160 { 0xFF0000, "red" },
161 { 0xBC8F8F, "rosybrown" },
162 { 0x4169E1, "royalblue" },
163 { 0x8B4513, "saddlebrown" },
164 { 0xFA8072, "salmon" },
165 { 0xF4A460, "sandybrown" },
166 { 0x2E8B57, "seagreen" },
167 { 0xFFF5EE, "seashell" },
168 { 0xA0522D, "sienna" },
169 { 0xC0C0C0, "silver" },
170 { 0x87CEEB, "skyblue" },
171 { 0x6A5ACD, "slateblue" },
172 { 0x708090, "slategray" },
173 { 0x708090, "slategrey" },
174 { 0xFFFAFA, "snow" },
175 { 0x00FF7F, "springgreen" },
176 { 0x4682B4, "steelblue" },
177 { 0xD2B48C, "tan" },
178 { 0x008080, "teal" },
179 { 0xD8BFD8, "thistle" },
180 { 0xFF6347, "tomato" },
181 { 0x40E0D0, "turquoise" },
182 { 0xEE82EE, "violet" },
183 { 0xF5DEB3, "wheat" },
184 { 0xFFFFFF, "white" },
185 { 0xF5F5F5, "whitesmoke" },
186 { 0xFFFF00, "yellow" },
187 { 0x9ACD32, "yellowgreen" }
188 };
190 static GHashTable *sp_svg_create_color_hash();
192 guint32
193 sp_svg_read_color(gchar const *str, guint32 const dfl)
194 {
195 return sp_svg_read_color(str, NULL, dfl);
196 }
198 static guint32
199 internal_sp_svg_read_color(gchar const *str, gchar const **end_ptr, guint32 def)
200 {
201 static GHashTable *colors = NULL;
202 guint32 val = 0;
204 if (str == NULL) return def;
205 while ((*str <= ' ') && *str) str++;
206 if (!*str) return def;
208 if (str[0] == '#') {
209 gint i;
210 for (i = 1; str[i]; i++) {
211 int hexval;
212 if (str[i] >= '0' && str[i] <= '9')
213 hexval = str[i] - '0';
214 else if (str[i] >= 'A' && str[i] <= 'F')
215 hexval = str[i] - 'A' + 10;
216 else if (str[i] >= 'a' && str[i] <= 'f')
217 hexval = str[i] - 'a' + 10;
218 else
219 break;
220 val = (val << 4) + hexval;
221 }
222 /* handle #rgb case */
223 if (i == 1 + 3) {
224 val = ((val & 0xf00) << 8) |
225 ((val & 0x0f0) << 4) |
226 (val & 0x00f);
227 val |= val << 4;
228 } else if (i != 1 + 6) {
229 /* must be either 3 or 6 digits. */
230 return def;
231 }
232 if (end_ptr) {
233 *end_ptr = str + i;
234 }
235 } else if (strneq(str, "rgb(", 4)) {
236 gboolean hasp, hasd;
237 gchar *s, *e;
238 gdouble r, g, b;
240 s = (gchar *) str + 4;
241 hasp = FALSE;
242 hasd = FALSE;
244 r = g_ascii_strtod(s, &e);
245 if (s == e) return def;
246 s = e;
247 if (*s == '%') {
248 hasp = TRUE;
249 s += 1;
250 } else {
251 hasd = TRUE;
252 }
253 while (*s && g_ascii_isspace(*s)) s += 1;
254 if (*s != ',') return def;
255 s += 1;
256 while (*s && g_ascii_isspace(*s)) s += 1;
257 g = g_ascii_strtod(s, &e);
258 if (s == e) return def;
259 s = e;
260 if (*s == '%') {
261 hasp = TRUE;
262 s += 1;
263 } else {
264 hasd = TRUE;
265 }
266 while (*s && g_ascii_isspace(*s)) s += 1;
267 if (*s != ',') return def;
268 s += 1;
269 while (*s && g_ascii_isspace(*s)) s += 1;
270 b = g_ascii_strtod(s, &e);
271 if (s == e) return def;
272 s = e;
273 if (*s == '%') {
274 hasp = TRUE;
275 } else {
276 hasd = TRUE;
277 }
278 while(*s && g_ascii_isspace(*s)) s += 1;
279 if (*s != ')') {
280 return def;
281 }
282 ++s;
283 if (hasp && hasd) return def;
284 if (hasp) {
285 val = (guint) floor(CLAMP(r, 0.0, 100.0) * 2.559999) << 24;
286 val |= ((guint) floor(CLAMP(g, 0.0, 100.0) * 2.559999) << 16);
287 val |= ((guint) floor(CLAMP(b, 0.0, 100.0) * 2.559999) << 8);
288 } else {
289 val = (guint) CLAMP(r, 0, 255) << 24;
290 val |= ((guint) CLAMP(g, 0, 255) << 16);
291 val |= ((guint) CLAMP(b, 0, 255) << 8);
292 }
293 if (end_ptr) {
294 *end_ptr = s;
295 }
296 return val;
297 } else {
298 gint i;
299 if (!colors) {
300 colors = sp_svg_create_color_hash();
301 }
302 gchar c[32];
303 for (i = 0; i < 31; i++) {
304 if (str[i] == ';' || g_ascii_isspace(str[i])) {
305 c[i] = '\0';
306 break;
307 }
308 c[i] = g_ascii_tolower(str[i]);
309 if (!str[i]) break;
310 }
311 c[31] = '\0';
313 gpointer const rgb_ptr = g_hash_table_lookup(colors, c);
314 if (rgb_ptr) {
315 val = *(static_cast<unsigned long *>(rgb_ptr));
316 } else {
317 return def;
318 }
319 if (end_ptr) {
320 *end_ptr = str + i;
321 }
322 }
324 return (val << 8);
325 }
327 guint32
328 sp_svg_read_color(gchar const *str, gchar const **end_ptr, guint32 dfl)
329 {
330 /* I've been rather hurried in editing the above to add support for end_ptr, so I'm adding
331 * this check wrapper. */
332 gchar const *end = str;
333 guint32 const ret = internal_sp_svg_read_color(str, &end, dfl);
334 assert(ret == dfl && end == str
335 || (((ret & 0xff) == 0)
336 && str < end));
337 if (str < end) {
338 gchar *buf = (gchar *) g_malloc(end + 1 - str);
339 memcpy(buf, str, end - str);
340 buf[end - str] = '\0';
341 gchar const *buf_end = buf;
342 guint32 const check = internal_sp_svg_read_color(buf, &buf_end, 1);
343 assert(check == ret
344 && buf_end - buf == end - str);
345 g_free(buf);
346 }
347 return ret;
348 }
351 /**
352 * Converts an RGB colour expressed in form 0x00rrggbb to a CSS/SVG representation of that colour.
353 * The result is valid even in SVG Tiny or non-SVG CSS.
354 */
355 static void
356 rgb24_to_css(char *const buf, unsigned const rgb24)
357 {
358 assert(rgb24 < (1u << 24));
360 /* SVG 1.1 Full allows additional colour names not supported by SVG Tiny, but we don't bother
361 * with them: it's good for these colours to be copyable to non-SVG CSS stylesheets and for
362 * documents to be more viewable in SVG Tiny/Basic viewers; and some of the SVG Full names are
363 * less meaningful than hex equivalents anyway. And it's easier for a person to map from the
364 * restricted set because the only component values are {00,80,ff}, other than silver 0xc0c0c0.
365 */
367 char const *src = NULL;
368 switch (rgb24) {
369 /* Extracted mechanically from the table at
370 * http://www.w3.org/TR/REC-html40/types.html#h-6.5 .*/
371 case 0x000000: src = "black"; break;
372 case 0xc0c0c0: src = "silver"; break;
373 case 0x808080: src = "gray"; break;
374 case 0xffffff: src = "white"; break;
375 case 0x800000: src = "maroon"; break;
376 case 0xff0000: src = "red"; break;
377 case 0x800080: src = "purple"; break;
378 case 0xff00ff: src = "fuchsia"; break;
379 case 0x008000: src = "green"; break;
380 case 0x00ff00: src = "lime"; break;
381 case 0x808000: src = "olive"; break;
382 case 0xffff00: src = "yellow"; break;
383 case 0x000080: src = "navy"; break;
384 case 0x0000ff: src = "blue"; break;
385 case 0x008080: src = "teal"; break;
386 case 0x00ffff: src = "aqua"; break;
388 default: {
389 if ((rgb24 & 0xf0f0f) * 0x11 == rgb24) {
390 /* Can use the shorter three-digit form #rgb instead of #rrggbb. */
391 sprintf(buf, "#%x%x%x",
392 (rgb24 >> 16) & 0xf,
393 (rgb24 >> 8) & 0xf,
394 rgb24 & 0xf);
395 } else {
396 sprintf(buf, "#%06x", rgb24);
397 }
398 break;
399 }
400 }
401 if (src) {
402 strcpy(buf, src);
403 }
405 assert(sp_svg_read_color(buf, 0xff) == (rgb24 << 8));
406 }
408 /**
409 * Converts an RGBA32 colour to a CSS/SVG representation of the RGB portion of that colour. The
410 * result is valid even in SVG Tiny or non-SVG CSS.
411 *
412 * \param rgba32 Colour expressed in form 0xrrggbbaa.
413 * \pre buflen \>= 8.
414 */
415 void
416 sp_svg_write_color(gchar *buf, unsigned const buflen, guint32 const rgba32)
417 {
418 g_assert(8 <= buflen);
420 unsigned const rgb24 = rgba32 >> 8;
421 rgb24_to_css(buf, rgb24);
422 }
424 static GHashTable *
425 sp_svg_create_color_hash()
426 {
427 GHashTable *colors = g_hash_table_new(g_str_hash, g_str_equal);
429 for (unsigned i = 0 ; i < G_N_ELEMENTS(sp_svg_color_named) ; i++) {
430 g_hash_table_insert(colors,
431 (gpointer)(sp_svg_color_named[i].name),
432 (gpointer)(&sp_svg_color_named[i].rgb));
433 }
435 return colors;
436 }
438 /*
439 Local Variables:
440 mode:c++
441 c-file-style:"stroustrup"
442 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
443 indent-tabs-mode:nil
444 fill-column:99
445 End:
446 */
447 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :