1 #define __SP_COLOR_C__
3 /** \file
4 * Colors and colorspaces.
5 *
6 * Author:
7 * Lauris Kaplinski <lauris@kaplinski.com>
8 * bulia byak <buliabyak@users.sf.net>
9 *
10 * Copyright (C) 2001-2002 Lauris Kaplinski
11 * Copyright (C) 2001 Ximian, Inc.
12 *
13 * Released under GNU GPL, read the file 'COPYING' for more information
14 */
16 #include <math.h>
17 #include "color.h"
19 /// A color space is just a name.
20 struct SPColorSpace {
21 gchar const *name;
22 };
24 static SPColorSpace const RGB = {"RGB"};
25 static SPColorSpace const CMYK = {"CMYK"};
27 /**
28 * Returns one of three values depending on if color is valid and if it
29 * has a valid color space. Likely redundant as soon as this is C++.
30 */
31 SPColorSpaceClass
32 sp_color_get_colorspace_class(SPColor const *color)
33 {
34 g_return_val_if_fail (color != NULL, SP_COLORSPACE_CLASS_INVALID);
36 if (color->colorspace == &RGB) return SP_COLORSPACE_CLASS_PROCESS;
37 if (color->colorspace == &CMYK) return SP_COLORSPACE_CLASS_PROCESS;
39 return SP_COLORSPACE_CLASS_UNKNOWN;
40 }
42 /**
43 * Returns the SPColorSpaceType corresponding to color's color space.
44 * \todo color->colorspace should simply be a named enum.
45 */
46 SPColorSpaceType
47 sp_color_get_colorspace_type(SPColor const *color)
48 {
49 g_return_val_if_fail (color != NULL, SP_COLORSPACE_TYPE_INVALID);
51 if (color->colorspace == &RGB) return SP_COLORSPACE_TYPE_RGB;
52 if (color->colorspace == &CMYK) return SP_COLORSPACE_TYPE_CMYK;
54 return SP_COLORSPACE_TYPE_UNKNOWN;
55 }
57 /**
58 * Shallow copy of color struct with NULL check.
59 */
60 void
61 sp_color_copy(SPColor *dst, SPColor const *src)
62 {
63 g_return_if_fail (dst != NULL);
64 g_return_if_fail (src != NULL);
66 *dst = *src;
67 }
69 /**
70 * Returns TRUE if c0 or c1 is NULL, or if colors/opacities differ.
71 */
72 gboolean
73 sp_color_is_equal (SPColor const *c0, SPColor const *c1)
74 {
75 g_return_val_if_fail (c0 != NULL, TRUE);
76 g_return_val_if_fail (c1 != NULL, TRUE);
78 if (c0->colorspace != c1->colorspace) return FALSE;
79 if (c0->v.c[0] != c1->v.c[0]) return FALSE;
80 if (c0->v.c[1] != c1->v.c[1]) return FALSE;
81 if (c0->v.c[2] != c1->v.c[2]) return FALSE;
82 if ((c0->colorspace == &CMYK) && (c0->v.c[3] != c1->v.c[3])) return FALSE;
84 return TRUE;
85 }
87 /**
88 * Returns TRUE if no RGB value differs epsilon or more in both colors,
89 * with CMYK aditionally comparing opacity, or if c0 or c1 is NULL.
90 * \note Do we want the latter?
91 */
92 gboolean
93 sp_color_is_close (SPColor const *c0, SPColor const *c1, float epsilon)
94 {
95 g_return_val_if_fail (c0 != NULL, TRUE);
96 g_return_val_if_fail (c1 != NULL, TRUE);
98 if (c0->colorspace != c1->colorspace) return FALSE;
99 if (fabs ((c0->v.c[0]) - (c1->v.c[0])) >= epsilon) return FALSE;
100 if (fabs ((c0->v.c[1]) - (c1->v.c[1])) >= epsilon) return FALSE;
101 if (fabs ((c0->v.c[2]) - (c1->v.c[2])) >= epsilon) return FALSE;
102 if ((c0->colorspace == &CMYK) && (fabs ((c0->v.c[3]) - (c1->v.c[3])) >= epsilon)) return FALSE;
104 return TRUE;
105 }
107 /**
108 * Sets RGB values and colorspace in color.
109 * \pre color != NULL && 0 <={r,g,b}<=1
110 */
111 void
112 sp_color_set_rgb_float(SPColor *color, float r, float g, float b)
113 {
114 g_return_if_fail(color != NULL);
115 g_return_if_fail(r >= 0.0);
116 g_return_if_fail(r <= 1.0);
117 g_return_if_fail(g >= 0.0);
118 g_return_if_fail(g <= 1.0);
119 g_return_if_fail(b >= 0.0);
120 g_return_if_fail(b <= 1.0);
122 color->colorspace = &RGB;
123 color->v.c[0] = r;
124 color->v.c[1] = g;
125 color->v.c[2] = b;
126 color->v.c[3] = 0;
127 }
129 /**
130 * Converts 32bit value to RGB floats and sets color.
131 * \pre color != NULL
132 */
133 void
134 sp_color_set_rgb_rgba32(SPColor *color, guint32 value)
135 {
136 g_return_if_fail (color != NULL);
138 color->colorspace = &RGB;
139 color->v.c[0] = (value >> 24) / 255.0F;
140 color->v.c[1] = ((value >> 16) & 0xff) / 255.0F;
141 color->v.c[2] = ((value >> 8) & 0xff) / 255.0F;
142 color->v.c[3] = 0;
143 }
145 /**
146 * Sets CMYK values and colorspace in color.
147 * \pre color != NULL && 0 <={c,m,y,k}<=1
148 */
149 void
150 sp_color_set_cmyk_float(SPColor *color, float c, float m, float y, float k)
151 {
152 g_return_if_fail(color != NULL);
153 g_return_if_fail(c >= 0.0);
154 g_return_if_fail(c <= 1.0);
155 g_return_if_fail(m >= 0.0);
156 g_return_if_fail(m <= 1.0);
157 g_return_if_fail(y >= 0.0);
158 g_return_if_fail(y <= 1.0);
159 g_return_if_fail(k >= 0.0);
160 g_return_if_fail(k <= 1.0);
162 color->colorspace = &CMYK;
163 color->v.c[0] = c;
164 color->v.c[1] = m;
165 color->v.c[2] = y;
166 color->v.c[3] = k;
167 }
169 /**
170 * Convert SPColor with integer alpha value to 32bit RGBA value.
171 * \pre color != NULL && alpha < 256
172 */
173 guint32
174 sp_color_get_rgba32_ualpha(SPColor const *color, guint32 alpha)
175 {
176 guint32 rgba;
178 g_return_val_if_fail (color != NULL, 0x0);
179 g_return_val_if_fail (alpha <= 0xff, 0x0);
181 if (color->colorspace == &RGB) {
182 rgba = SP_RGBA32_U_COMPOSE(SP_COLOR_F_TO_U(color->v.c[0]),
183 SP_COLOR_F_TO_U(color->v.c[1]),
184 SP_COLOR_F_TO_U(color->v.c[2]),
185 alpha);
186 } else {
187 float rgb[3];
188 sp_color_get_rgb_floatv (color, rgb);
189 rgba = SP_RGBA32_U_COMPOSE(SP_COLOR_F_TO_U(rgb[0]),
190 SP_COLOR_F_TO_U(rgb[1]),
191 SP_COLOR_F_TO_U(rgb[2]),
192 alpha);
193 }
195 return rgba;
196 }
198 /**
199 * Convert SPColor with float alpha value to 32bit RGBA value.
200 * \pre color != NULL && 0 <= alpha <= 1
201 */
202 guint32
203 sp_color_get_rgba32_falpha(SPColor const *color, float alpha)
204 {
205 g_return_val_if_fail(color != NULL, 0x0);
206 g_return_val_if_fail(alpha >= 0.0, 0x0);
207 g_return_val_if_fail(alpha <= 1.0, 0x0);
209 return sp_color_get_rgba32_ualpha(color, SP_COLOR_F_TO_U(alpha));
210 }
212 /**
213 * Fill rgb float array with values from SPColor.
214 * \pre color != NULL && rgb != NULL && rgb[0-2] is meaningful
215 */
216 void
217 sp_color_get_rgb_floatv(SPColor const *color, float *rgb)
218 {
219 g_return_if_fail (color != NULL);
220 g_return_if_fail (rgb != NULL);
222 if (color->colorspace == &RGB) {
223 rgb[0] = color->v.c[0];
224 rgb[1] = color->v.c[1];
225 rgb[2] = color->v.c[2];
226 } else if (color->colorspace == &CMYK) {
227 sp_color_cmyk_to_rgb_floatv(rgb,
228 color->v.c[0],
229 color->v.c[1],
230 color->v.c[2],
231 color->v.c[3]);
232 }
233 }
235 /**
236 * Fill cmyk float array with values from SPColor.
237 * \pre color != NULL && cmyk != NULL && cmyk[0-3] is meaningful
238 */
239 void
240 sp_color_get_cmyk_floatv(SPColor const *color, float *cmyk)
241 {
242 g_return_if_fail (color != NULL);
243 g_return_if_fail (cmyk != NULL);
245 if (color->colorspace == &CMYK) {
246 cmyk[0] = color->v.c[0];
247 cmyk[1] = color->v.c[1];
248 cmyk[2] = color->v.c[2];
249 cmyk[3] = color->v.c[3];
250 } else if (color->colorspace == &RGB) {
251 sp_color_rgb_to_cmyk_floatv(cmyk,
252 color->v.c[0],
253 color->v.c[1],
254 color->v.c[2]);
255 }
256 }
258 /* Plain mode helpers */
260 /**
261 * Fill hsv float array from r,g,b float values.
262 */
263 void
264 sp_color_rgb_to_hsv_floatv (float *hsv, float r, float g, float b)
265 {
266 float max, min, delta;
268 max = MAX (MAX (r, g), b);
269 min = MIN (MIN (r, g), b);
270 delta = max - min;
272 hsv[2] = max;
274 if (max > 0) {
275 hsv[1] = delta / max;
276 } else {
277 hsv[1] = 0.0;
278 }
280 if (hsv[1] != 0.0) {
281 if (r == max) {
282 hsv[0] = (g - b) / delta;
283 } else if (g == max) {
284 hsv[0] = 2.0 + (b - r) / delta;
285 } else {
286 hsv[0] = 4.0 + (r - g) / delta;
287 }
289 hsv[0] = hsv[0] / 6.0;
291 if (hsv[0] < 0) hsv[0] += 1.0;
292 }
293 }
295 /**
296 * Fill rgb float array from h,s,v float values.
297 */
298 void
299 sp_color_hsv_to_rgb_floatv (float *rgb, float h, float s, float v)
300 {
301 gdouble f, w, q, t, d;
303 d = h * 5.99999999;
304 f = d - floor (d);
305 w = v * (1.0 - s);
306 q = v * (1.0 - (s * f));
307 t = v * (1.0 - (s * (1.0 - f)));
309 if (d < 1.0) {
310 *rgb++ = v;
311 *rgb++ = t;
312 *rgb++ = w;
313 } else if (d < 2.0) {
314 *rgb++ = q;
315 *rgb++ = v;
316 *rgb++ = w;
317 } else if (d < 3.0) {
318 *rgb++ = w;
319 *rgb++ = v;
320 *rgb++ = t;
321 } else if (d < 4.0) {
322 *rgb++ = w;
323 *rgb++ = q;
324 *rgb++ = v;
325 } else if (d < 5.0) {
326 *rgb++ = t;
327 *rgb++ = w;
328 *rgb++ = v;
329 } else {
330 *rgb++ = v;
331 *rgb++ = w;
332 *rgb++ = q;
333 }
334 }
336 /**
337 * Fill hsl float array from r,g,b float values.
338 */
339 void
340 sp_color_rgb_to_hsl_floatv (float *hsl, float r, float g, float b)
341 {
342 float max = MAX (MAX (r, g), b);
343 float min = MIN (MIN (r, g), b);
344 float delta = max - min;
346 hsl[2] = (max + min)/2.0;
348 if (delta == 0) {
349 hsl[0] = 0;
350 hsl[1] = 0;
351 } else {
352 if (hsl[2] <= 0.5)
353 hsl[1] = delta / (max + min);
354 else
355 hsl[1] = delta / (2 - max - min);
357 if (r == max) hsl[0] = (g - b) / delta;
358 else if (g == max) hsl[0] = 2.0 + (b - r) / delta;
359 else if (b == max) hsl[0] = 4.0 + (r - g) / delta;
361 hsl[0] = hsl[0] / 6.0;
363 if (hsl[0] < 0) hsl[0] += 1;
364 if (hsl[0] > 1) hsl[0] -= 1;
365 }
366 }
368 float
369 hue_2_rgb (float v1, float v2, float h)
370 {
371 if (h < 0) h += 6.0;
372 if (h > 6) h -= 6.0;
374 if (h < 1) return v1 + (v2 - v1) * h;
375 if (h < 3) return v2;
376 if (h < 4) return v1 + (v2 - v1) * (4 - h);
377 return v1;
378 }
380 /**
381 * Fill rgb float array from h,s,l float values.
382 */
383 void
384 sp_color_hsl_to_rgb_floatv (float *rgb, float h, float s, float l)
385 {
386 if (s == 0) {
387 rgb[0] = l;
388 rgb[1] = l;
389 rgb[2] = l;
390 } else {
391 float v2;
392 if (l < 0.5) {
393 v2 = l * (1 + s);
394 } else {
395 v2 = l + s - l*s;
396 }
397 float v1 = 2*l - v2;
399 rgb[0] = hue_2_rgb (v1, v2, h*6 + 2.0);
400 rgb[1] = hue_2_rgb (v1, v2, h*6);
401 rgb[2] = hue_2_rgb (v1, v2, h*6 - 2.0);
402 }
403 }
405 /**
406 * Fill cmyk float array from r,g,b float values.
407 */
408 void
409 sp_color_rgb_to_cmyk_floatv (float *cmyk, float r, float g, float b)
410 {
411 float c, m, y, k, kd;
413 c = 1.0 - r;
414 m = 1.0 - g;
415 y = 1.0 - b;
416 k = MIN (MIN (c, m), y);
418 c = c - k;
419 m = m - k;
420 y = y - k;
422 kd = 1.0 - k;
424 if (kd > 1e-9) {
425 c = c / kd;
426 m = m / kd;
427 y = y / kd;
428 }
430 cmyk[0] = c;
431 cmyk[1] = m;
432 cmyk[2] = y;
433 cmyk[3] = k;
434 }
436 /**
437 * Fill rgb float array from c,m,y,k float values.
438 */
439 void
440 sp_color_cmyk_to_rgb_floatv (float *rgb, float c, float m, float y, float k)
441 {
442 float kd;
444 kd = 1.0 - k;
446 c = c * kd;
447 m = m * kd;
448 y = y * kd;
450 c = c + k;
451 m = m + k;
452 y = y + k;
454 rgb[0] = 1.0 - c;
455 rgb[1] = 1.0 - m;
456 rgb[2] = 1.0 - y;
457 }
459 /*
460 Local Variables:
461 mode:c++
462 c-file-style:"stroustrup"
463 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
464 indent-tabs-mode:nil
465 fill-column:99
466 End:
467 */
468 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :