xref: /openbsd-src/lib/libcurses/base/lib_color.c (revision f3e2efddedcd14d4f5420fb6d8bdeffe9370bfe0)
1 /*	$OpenBSD: lib_color.c,v 1.7 2000/03/26 16:45:03 millert Exp $	*/
2 
3 /****************************************************************************
4  * Copyright (c) 1998,1999,2000 Free Software Foundation, Inc.              *
5  *                                                                          *
6  * Permission is hereby granted, free of charge, to any person obtaining a  *
7  * copy of this software and associated documentation files (the            *
8  * "Software"), to deal in the Software without restriction, including      *
9  * without limitation the rights to use, copy, modify, merge, publish,      *
10  * distribute, distribute with modifications, sublicense, and/or sell       *
11  * copies of the Software, and to permit persons to whom the Software is    *
12  * furnished to do so, subject to the following conditions:                 *
13  *                                                                          *
14  * The above copyright notice and this permission notice shall be included  *
15  * in all copies or substantial portions of the Software.                   *
16  *                                                                          *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
20  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
21  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
22  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
23  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
24  *                                                                          *
25  * Except as contained in this notice, the name(s) of the above copyright   *
26  * holders shall not be used in advertising or otherwise to promote the     *
27  * sale, use or other dealings in this Software without prior written       *
28  * authorization.                                                           *
29  ****************************************************************************/
30 
31 /****************************************************************************
32  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
33  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
34  ****************************************************************************/
35 
36 /* lib_color.c
37  *
38  * Handles color emulation of SYS V curses
39  */
40 
41 #include <curses.priv.h>
42 
43 #include <term.h>
44 #include <tic.h>
45 
46 MODULE_ID("$From: lib_color.c,v 1.49 2000/03/26 03:12:12 tom Exp $")
47 
48 /*
49  * These should be screen structure members.  They need to be globals for
50  * historical reasons.  So we assign them in start_color() and also in
51  * set_term()'s screen-switching logic.
52  */
53 int COLOR_PAIRS = 0;
54 int COLORS = 0;
55 
56 /*
57  * Given a RGB range of 0..1000, we'll normally set the individual values
58  * to about 2/3 of the maximum, leaving full-range for bold/bright colors.
59  */
60 #define RGB_ON  680
61 #define RGB_OFF 0
62 /* *INDENT-OFF* */
63 static const color_t cga_palette[] =
64 {
65     /*  R               G               B */
66     {RGB_OFF,		RGB_OFF,	RGB_OFF},	/* COLOR_BLACK */
67     {RGB_ON,		RGB_OFF,	RGB_OFF},	/* COLOR_RED */
68     {RGB_OFF,		RGB_ON,		RGB_OFF},	/* COLOR_GREEN */
69     {RGB_ON,		RGB_ON,		RGB_OFF},	/* COLOR_YELLOW */
70     {RGB_OFF,		RGB_OFF,	RGB_ON},	/* COLOR_BLUE */
71     {RGB_ON,		RGB_OFF,	RGB_ON},	/* COLOR_MAGENTA */
72     {RGB_OFF,		RGB_ON,		RGB_ON},	/* COLOR_CYAN */
73     {RGB_ON,		RGB_ON,		RGB_ON},	/* COLOR_WHITE */
74 };
75 
76 static const color_t hls_palette[] =
77 {
78     /*  H       L       S */
79     {	0,	0,	0},		/* COLOR_BLACK */
80     {	120,	50,	100},		/* COLOR_RED */
81     {	240,	50,	100},		/* COLOR_GREEN */
82     {	180,	50,	100},		/* COLOR_YELLOW */
83     {	330,	50,	100},		/* COLOR_BLUE */
84     {	60,	50,	100},		/* COLOR_MAGENTA */
85     {	300,	50,	100},		/* COLOR_CYAN */
86     {	0,	50,	100},		/* COLOR_WHITE */
87 };
88 /* *INDENT-ON* */
89 
90 #ifdef NCURSES_EXT_FUNCS
91 /*
92  * These are called from _nc_do_color(), which in turn is called from
93  * vidattr - so we have to assume that SP may be null.
94  */
95 static int
96 default_fg(void)
97 {
98     return (SP != 0) ? SP->_default_fg : COLOR_WHITE;
99 }
100 
101 static int
102 default_bg(void)
103 {
104     return SP != 0 ? SP->_default_bg : COLOR_BLACK;
105 }
106 #else
107 #define default_fg() COLOR_WHITE
108 #define default_bg() COLOR_BLACK
109 #endif
110 
111 /*
112  * SVr4 curses is known to interchange color codes (1,4) and (3,6), possibly
113  * to maintain compatibility with a pre-ANSI scheme.  The same scheme is
114  * also used in the FreeBSD syscons.
115  */
116 static int
117 toggled_colors(int c)
118 {
119     if (c < 16) {
120 	static const int table[] =
121 	{0, 4, 2, 6, 1, 5, 3, 7,
122 	    8, 12, 10, 14, 9, 13, 11, 15};
123 	c = table[c];
124     }
125     return c;
126 }
127 
128 static void
129 set_background_color(int bg, int (*outc) (int))
130 {
131     if (set_a_background) {
132 	TPUTS_TRACE("set_a_background");
133 	tputs(tparm(set_a_background, bg), 1, outc);
134     } else {
135 	TPUTS_TRACE("set_background");
136 	tputs(tparm(set_background, toggled_colors(bg)), 1, outc);
137     }
138 }
139 
140 static void
141 set_foreground_color(int fg, int (*outc) (int))
142 {
143     if (set_a_foreground) {
144 	TPUTS_TRACE("set_a_foreground");
145 	tputs(tparm(set_a_foreground, fg), 1, outc);
146     } else {
147 	TPUTS_TRACE("set_foreground");
148 	tputs(tparm(set_foreground, toggled_colors(fg)), 1, outc);
149     }
150 }
151 
152 static bool
153 set_original_colors(void)
154 {
155     if (orig_pair != 0) {
156 	TPUTS_TRACE("orig_pair");
157 	putp(orig_pair);
158 	return TRUE;
159     } else if (orig_colors != NULL) {
160 	TPUTS_TRACE("orig_colors");
161 	putp(orig_colors);
162 	return TRUE;
163     }
164     return FALSE;
165 }
166 
167 int
168 start_color(void)
169 {
170     int n;
171     const color_t *tp;
172 
173     T((T_CALLED("start_color()")));
174 
175     if (set_original_colors() != TRUE) {
176 	set_foreground_color(default_fg(), _nc_outch);
177 	set_background_color(default_bg(), _nc_outch);
178     }
179 
180     if (VALID_NUMERIC(max_pairs))
181 	COLOR_PAIRS = SP->_pair_count = max_pairs;
182     else
183 	returnCode(ERR);
184     if ((SP->_color_pairs = typeCalloc(unsigned short, max_pairs)) == 0)
185 	  returnCode(ERR);
186     SP->_color_pairs[0] = PAIR_OF(default_fg(), default_bg());
187     if (VALID_NUMERIC(max_colors))
188 	COLORS = SP->_color_count = max_colors;
189     else
190 	returnCode(ERR);
191     SP->_coloron = 1;
192 
193     if ((SP->_color_table = typeMalloc(color_t, COLORS)) == 0)
194 	returnCode(ERR);
195     tp = (hue_lightness_saturation) ? hls_palette : cga_palette;
196     for (n = 0; n < COLORS; n++) {
197 	if (n < 8) {
198 	    SP->_color_table[n] = tp[n];
199 	} else {
200 	    SP->_color_table[n] = tp[n % 8];
201 	    if (hue_lightness_saturation) {
202 		SP->_color_table[n].green = 100;
203 	    } else {
204 		if (SP->_color_table[n].red)
205 		    SP->_color_table[n].red = 1000;
206 		if (SP->_color_table[n].green)
207 		    SP->_color_table[n].green = 1000;
208 		if (SP->_color_table[n].blue)
209 		    SP->_color_table[n].blue = 1000;
210 	    }
211 	}
212     }
213 
214     T(("started color: COLORS = %d, COLOR_PAIRS = %d", COLORS, COLOR_PAIRS));
215 
216     returnCode(OK);
217 }
218 
219 /* This function was originally written by Daniel Weaver <danw@znyx.com> */
220 static void
221 rgb2hls(short r, short g, short b, short *h, short *l, short *s)
222 /* convert RGB to HLS system */
223 {
224     short min, max, t;
225 
226     if ((min = g < r ? g : r) > b)
227 	min = b;
228     if ((max = g > r ? g : r) < b)
229 	max = b;
230 
231     /* calculate lightness */
232     *l = (min + max) / 20;
233 
234     if (min == max) {		/* black, white and all shades of gray */
235 	*h = 0;
236 	*s = 0;
237 	return;
238     }
239 
240     /* calculate saturation */
241     if (*l < 50)
242 	*s = ((max - min) * 100) / (max + min);
243     else
244 	*s = ((max - min) * 100) / (2000 - max - min);
245 
246     /* calculate hue */
247     if (r == max)
248 	t = 120 + ((g - b) * 60) / (max - min);
249     else if (g == max)
250 	t = 240 + ((b - r) * 60) / (max - min);
251     else
252 	t = 360 + ((r - g) * 60) / (max - min);
253 
254     *h = t % 360;
255 }
256 
257 /*
258  * Extension (1997/1/18) - Allow negative f/b values to set default color
259  * values.
260  */
261 int
262 init_pair(short pair, short f, short b)
263 {
264     unsigned result;
265 
266     T((T_CALLED("init_pair(%d,%d,%d)"), pair, f, b));
267 
268     if ((pair < 0) || (pair >= COLOR_PAIRS))
269 	returnCode(ERR);
270 #ifdef NCURSES_EXT_FUNCS
271     if (SP->_default_color) {
272 	if (f < 0)
273 	    f = C_MASK;
274 	if (b < 0)
275 	    b = C_MASK;
276 	if (f >= COLORS && f != C_MASK)
277 	    returnCode(ERR);
278 	if (b >= COLORS && b != C_MASK)
279 	    returnCode(ERR);
280     } else
281 #endif
282     {
283 	if ((f < 0) || (f >= COLORS)
284 	    || (b < 0) || (b >= COLORS)
285 	    || (pair < 1))
286 	    returnCode(ERR);
287     }
288 
289     /*
290      * When a pair's content is changed, replace its colors (if pair was
291      * initialized before a screen update is performed replacing original
292      * pair colors with the new ones).
293      */
294     result = PAIR_OF(f, b);
295     if (SP->_color_pairs[pair] != 0
296 	&& SP->_color_pairs[pair] != result) {
297 	int y, x;
298 	attr_t z = COLOR_PAIR(pair);
299 
300 	for (y = 0; y <= curscr->_maxy; y++) {
301 	    struct ldat *ptr = &(curscr->_line[y]);
302 	    bool changed = FALSE;
303 	    for (x = 0; x <= curscr->_maxx; x++) {
304 		if ((ptr->text[x] & A_COLOR) == z) {
305 		    /* Set the old cell to zero to ensure it will be
306 		       updated on the next doupdate() */
307 		    ptr->text[x] = 0;
308 		    CHANGED_CELL(ptr, x);
309 		    changed = TRUE;
310 		}
311 	    }
312 	    if (changed)
313 		_nc_make_oldhash(y);
314 	}
315     }
316     SP->_color_pairs[pair] = result;
317     if ((int)(SP->_current_attr & A_COLOR) == COLOR_PAIR(pair))
318 	SP->_current_attr |= A_COLOR;	/* force attribute update */
319 
320     if (initialize_pair) {
321 	const color_t *tp = hue_lightness_saturation ? hls_palette : cga_palette;
322 
323 	T(("initializing pair: pair = %d, fg=(%d,%d,%d), bg=(%d,%d,%d)",
324 		pair,
325 		tp[f].red, tp[f].green, tp[f].blue,
326 		tp[b].red, tp[b].green, tp[b].blue));
327 
328 	if (initialize_pair) {
329 	    TPUTS_TRACE("initialize_pair");
330 	    putp(tparm(initialize_pair,
331 		    pair,
332 		    tp[f].red, tp[f].green, tp[f].blue,
333 		    tp[b].red, tp[b].green, tp[b].blue));
334 	}
335     }
336 
337     returnCode(OK);
338 }
339 
340 int
341 init_color(short color, short r, short g, short b)
342 {
343     T((T_CALLED("init_color(%d,%d,%d,%d)"), color, r, g, b));
344 
345     if (initialize_color == NULL)
346 	returnCode(ERR);
347 
348     if (color < 0 || color >= COLORS)
349 	returnCode(ERR);
350     if (r < 0 || r > 1000 || g < 0 || g > 1000 || b < 0 || b > 1000)
351 	returnCode(ERR);
352 
353     if (hue_lightness_saturation)
354 	rgb2hls(r, g, b,
355 	    &SP->_color_table[color].red,
356 	    &SP->_color_table[color].green,
357 	    &SP->_color_table[color].blue);
358     else {
359 	SP->_color_table[color].red = r;
360 	SP->_color_table[color].green = g;
361 	SP->_color_table[color].blue = b;
362     }
363 
364     if (initialize_color) {
365 	TPUTS_TRACE("initialize_color");
366 	putp(tparm(initialize_color, color, r, g, b));
367     }
368     returnCode(OK);
369 }
370 
371 bool
372 can_change_color(void)
373 {
374     T((T_CALLED("can_change_color()")));
375     returnCode((can_change != 0) ? TRUE : FALSE);
376 }
377 
378 bool
379 has_colors(void)
380 {
381     T((T_CALLED("has_colors()")));
382     returnCode((VALID_NUMERIC(max_colors) && VALID_NUMERIC(max_pairs)
383 	    && (((set_foreground != NULL)
384 		    && (set_background != NULL))
385 		|| ((set_a_foreground != NULL)
386 		    && (set_a_background != NULL))
387 		|| set_color_pair)) ? TRUE : FALSE);
388 }
389 
390 int
391 color_content(short color, short *r, short *g, short *b)
392 {
393     T((T_CALLED("color_content(%d,%p,%p,%p)"), color, r, g, b));
394     if (color < 0 || color >= COLORS)
395 	returnCode(ERR);
396 
397     if (r)
398 	*r = SP->_color_table[color].red;
399     if (g)
400 	*g = SP->_color_table[color].green;
401     if (b)
402 	*b = SP->_color_table[color].blue;
403     returnCode(OK);
404 }
405 
406 int
407 pair_content(short pair, short *f, short *b)
408 {
409     T((T_CALLED("pair_content(%d,%p,%p)"), pair, f, b));
410 
411     if ((pair < 0) || (pair >= COLOR_PAIRS))
412 	returnCode(ERR);
413     if (f)
414 	*f = ((SP->_color_pairs[pair] >> C_SHIFT) & C_MASK);
415     if (b)
416 	*b = (SP->_color_pairs[pair] & C_MASK);
417 
418     returnCode(OK);
419 }
420 
421 void
422 _nc_do_color(int old_pair, int pair, bool reverse, int (*outc) (int))
423 {
424     short fg = C_MASK, bg = C_MASK;
425     short old_fg, old_bg;
426 
427     if (pair != 0) {
428 	if (set_color_pair) {
429 	    TPUTS_TRACE("set_color_pair");
430 	    tputs(tparm(set_color_pair, pair), 1, outc);
431 	    return;
432 	} else if (SP != 0) {
433 	    pair_content(pair, &fg, &bg);
434 	}
435     }
436 
437     if (old_pair >= 0 && SP != 0) {
438 	pair_content(old_pair, &old_fg, &old_bg);
439 	if ((fg == C_MASK && old_fg != C_MASK)
440 	    || (bg == C_MASK && old_bg != C_MASK)) {
441 #ifdef NCURSES_EXT_FUNCS
442 	    /*
443 	     * A minor optimization - but extension.  If "AX" is specified in
444 	     * the terminal description, treat it as screen's indicator of ECMA
445 	     * SGR 39 and SGR 49, and assume the two sequences are independent.
446 	     */
447 	    if (SP->_has_sgr_39_49 && old_bg == C_MASK && old_fg != C_MASK) {
448 		tputs("\033[39m", 1, outc);
449 	    } else if (SP->_has_sgr_39_49 && old_fg == C_MASK && old_bg != C_MASK) {
450 		tputs("\033[49m", 1, outc);
451 	    } else
452 #endif
453 		set_original_colors();
454 	}
455     } else {
456 	set_original_colors();
457 	if (old_pair < 0)
458 	    return;
459     }
460 
461 #ifdef NCURSES_EXT_FUNCS
462     if (fg == C_MASK)
463 	fg = default_fg();
464     if (bg == C_MASK)
465 	bg = default_bg();
466 #endif
467 
468     if (reverse) {
469 	short xx = fg;
470 	fg = bg;
471 	bg = xx;
472     }
473 
474     T(("setting colors: pair = %d, fg = %d, bg = %d", pair, fg, bg));
475 
476     if (fg != C_MASK) {
477 	set_foreground_color(fg, outc);
478     }
479     if (bg != C_MASK) {
480 	set_background_color(bg, outc);
481     }
482 }
483