1 /****************************************************************************
2  * Copyright (c) 1998-2009,2010 Free Software Foundation, Inc.              *
3  *                                                                          *
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5  * copy of this software and associated documentation files (the            *
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9  * copies of the Software, and to permit persons to whom the Software is    *
10  * furnished to do so, subject to the following conditions:                 *
11  *                                                                          *
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14  *                                                                          *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
16  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
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22  *                                                                          *
23  * Except as contained in this notice, the name(s) of the above copyright   *
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28 
29 /****************************************************************************
30  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
31  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
32  *     and: Thomas E. Dickey                        1996-on                 *
33  *     and: Juergen Pfeifer                         2009                    *
34  ****************************************************************************/
35 
36 /* lib_color.c
37  *
38  * Handles color emulation of SYS V curses
39  */
40 
41 #include <curses.priv.h>
42 #include <tic.h>
43 
44 #ifndef CUR
45 #define CUR SP_TERMTYPE
46 #endif
47 
48 MODULE_ID("$Id: lib_color.c,v 1.98 2010/04/24 22:57:53 tom Exp $")
49 
50 #ifdef USE_TERM_DRIVER
51 #define CanChange      InfoOf(SP_PARM).canchange
52 #define DefaultPalette InfoOf(SP_PARM).defaultPalette
53 #define HasColor       InfoOf(SP_PARM).hascolor
54 #define InitColor      InfoOf(SP_PARM).initcolor
55 #define MaxColors      InfoOf(SP_PARM).maxcolors
56 #define MaxPairs       InfoOf(SP_PARM).maxpairs
57 #define UseHlsPalette  (DefaultPalette == _nc_hls_palette)
58 #else
59 #define CanChange      can_change
60 #define DefaultPalette (hue_lightness_saturation ? hls_palette : cga_palette)
61 #define HasColor       has_color
62 #define InitColor      initialize_color
63 #define MaxColors      max_colors
64 #define MaxPairs       max_pairs
65 #define UseHlsPalette  (hue_lightness_saturation)
66 #endif
67 
68 #ifndef USE_TERM_DRIVER
69 /*
70  * These should be screen structure members.  They need to be globals for
71  * historical reasons.  So we assign them in start_color() and also in
72  * set_term()'s screen-switching logic.
73  */
74 #if USE_REENTRANT
75 NCURSES_EXPORT(int)
76 NCURSES_PUBLIC_VAR(COLOR_PAIRS) (void)
77 {
78     return SP ? SP->_pair_count : -1;
79 }
80 NCURSES_EXPORT(int)
81 NCURSES_PUBLIC_VAR(COLORS) (void)
82 {
83     return SP ? SP->_color_count : -1;
84 }
85 #else
86 NCURSES_EXPORT_VAR(int) COLOR_PAIRS = 0;
87 NCURSES_EXPORT_VAR(int) COLORS = 0;
88 #endif
89 #endif /* !USE_TERM_DRIVER */
90 
91 #define DATA(r,g,b) {r,g,b, 0,0,0, 0}
92 
93 #define TYPE_CALLOC(type,elts) typeCalloc(type, (unsigned)(elts))
94 
95 #define MAX_PALETTE	8
96 
97 #define OkColorHi(n)	(((n) < COLORS) && ((n) < maxcolors))
98 #define InPalette(n)	((n) >= 0 && (n) < MAX_PALETTE)
99 
100 /*
101  * Given a RGB range of 0..1000, we'll normally set the individual values
102  * to about 2/3 of the maximum, leaving full-range for bold/bright colors.
103  */
104 #define RGB_ON  680
105 #define RGB_OFF 0
106 /* *INDENT-OFF* */
107 static const color_t cga_palette[] =
108 {
109     /*  R               G               B */
110     DATA(RGB_OFF,	RGB_OFF,	RGB_OFF),	/* COLOR_BLACK */
111     DATA(RGB_ON,	RGB_OFF,	RGB_OFF),	/* COLOR_RED */
112     DATA(RGB_OFF,	RGB_ON,		RGB_OFF),	/* COLOR_GREEN */
113     DATA(RGB_ON,	RGB_ON,		RGB_OFF),	/* COLOR_YELLOW */
114     DATA(RGB_OFF,	RGB_OFF,	RGB_ON),	/* COLOR_BLUE */
115     DATA(RGB_ON,	RGB_OFF,	RGB_ON),	/* COLOR_MAGENTA */
116     DATA(RGB_OFF,	RGB_ON,		RGB_ON),	/* COLOR_CYAN */
117     DATA(RGB_ON,	RGB_ON,		RGB_ON),	/* COLOR_WHITE */
118 };
119 
120 static const color_t hls_palette[] =
121 {
122     /*  	H       L       S */
123     DATA(	0,	0,	0),		/* COLOR_BLACK */
124     DATA(	120,	50,	100),		/* COLOR_RED */
125     DATA(	240,	50,	100),		/* COLOR_GREEN */
126     DATA(	180,	50,	100),		/* COLOR_YELLOW */
127     DATA(	330,	50,	100),		/* COLOR_BLUE */
128     DATA(	60,	50,	100),		/* COLOR_MAGENTA */
129     DATA(	300,	50,	100),		/* COLOR_CYAN */
130     DATA(	0,	50,	100),		/* COLOR_WHITE */
131 };
132 
133 #ifdef USE_TERM_DRIVER
134 NCURSES_EXPORT_VAR(const color_t*) _nc_cga_palette = cga_palette;
135 NCURSES_EXPORT_VAR(const color_t*) _nc_hls_palette = hls_palette;
136 #endif
137 
138 /* *INDENT-ON* */
139 
140 /*
141  * Ensure that we use color pairs only when colors have been started, and also
142  * that the index is within the limits of the table which we allocated.
143  */
144 #define ValidPair(pair) \
145     ((SP_PARM != 0) && (pair >= 0) && (pair < SP_PARM->_pair_limit) && SP_PARM->_coloron)
146 
147 #if NCURSES_EXT_FUNCS
148 /*
149  * These are called from _nc_do_color(), which in turn is called from
150  * vidattr - so we have to assume that sp may be null.
151  */
152 static int
153 default_fg(NCURSES_SP_DCL0)
154 {
155     return (SP_PARM != 0) ? SP_PARM->_default_fg : COLOR_WHITE;
156 }
157 
158 static int
159 default_bg(NCURSES_SP_DCL0)
160 {
161     return SP_PARM != 0 ? SP_PARM->_default_bg : COLOR_BLACK;
162 }
163 #else
164 #define default_fg(sp) COLOR_WHITE
165 #define default_bg(sp) COLOR_BLACK
166 #endif
167 
168 #ifndef USE_TERM_DRIVER
169 /*
170  * SVr4 curses is known to interchange color codes (1,4) and (3,6), possibly
171  * to maintain compatibility with a pre-ANSI scheme.  The same scheme is
172  * also used in the FreeBSD syscons.
173  */
174 static int
175 toggled_colors(int c)
176 {
177     if (c < 16) {
178 	static const int table[] =
179 	{0, 4, 2, 6, 1, 5, 3, 7,
180 	 8, 12, 10, 14, 9, 13, 11, 15};
181 	c = table[c];
182     }
183     return c;
184 }
185 #endif
186 
187 static void
188 set_background_color(NCURSES_SP_DCLx int bg, NCURSES_SP_OUTC outc)
189 {
190 #ifdef USE_TERM_DRIVER
191     CallDriver_3(SP_PARM, color, FALSE, bg, outc);
192 #else
193     if (set_a_background) {
194 	TPUTS_TRACE("set_a_background");
195 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
196 				TPARM_1(set_a_background, bg),
197 				1, outc);
198     } else {
199 	TPUTS_TRACE("set_background");
200 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
201 				TPARM_1(set_background, toggled_colors(bg)),
202 				1, outc);
203     }
204 #endif
205 }
206 
207 static void
208 set_foreground_color(NCURSES_SP_DCLx int fg, NCURSES_SP_OUTC outc)
209 {
210 #ifdef USE_TERM_DRIVER
211     CallDriver_3(SP_PARM, color, TRUE, fg, outc);
212 #else
213     if (set_a_foreground) {
214 	TPUTS_TRACE("set_a_foreground");
215 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
216 				TPARM_1(set_a_foreground, fg),
217 				1, outc);
218     } else {
219 	TPUTS_TRACE("set_foreground");
220 	NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
221 				TPARM_1(set_foreground, toggled_colors(fg)),
222 				1, outc);
223     }
224 #endif
225 }
226 
227 static void
228 init_color_table(NCURSES_SP_DCL0)
229 {
230     const color_t *tp = DefaultPalette;
231     int n;
232 
233     assert(tp != 0);
234 
235     for (n = 0; n < COLORS; n++) {
236 	if (InPalette(n)) {
237 	    SP_PARM->_color_table[n] = tp[n];
238 	} else {
239 	    SP_PARM->_color_table[n] = tp[n % MAX_PALETTE];
240 	    if (UseHlsPalette) {
241 		SP_PARM->_color_table[n].green = 100;
242 	    } else {
243 		if (SP_PARM->_color_table[n].red)
244 		    SP_PARM->_color_table[n].red = 1000;
245 		if (SP_PARM->_color_table[n].green)
246 		    SP_PARM->_color_table[n].green = 1000;
247 		if (SP_PARM->_color_table[n].blue)
248 		    SP_PARM->_color_table[n].blue = 1000;
249 	    }
250 	}
251     }
252 }
253 
254 /*
255  * Reset the color pair, e.g., to whatever color pair 0 is.
256  */
257 static bool
258 reset_color_pair(NCURSES_SP_DCL0)
259 {
260 #ifdef USE_TERM_DRIVER
261     return CallDriver(SP_PARM, rescol);
262 #else
263     bool result = FALSE;
264 
265     (void) SP_PARM;
266     if (orig_pair != 0) {
267 	TPUTS_TRACE("orig_pair");
268 	putp(orig_pair);
269 	result = TRUE;
270     }
271     return result;
272 #endif
273 }
274 
275 /*
276  * Reset color pairs and definitions.  Actually we do both more to accommodate
277  * badly-written terminal descriptions than for the relatively rare case where
278  * someone has changed the color definitions.
279  */
280 NCURSES_EXPORT(bool)
281 NCURSES_SP_NAME(_nc_reset_colors) (NCURSES_SP_DCL0)
282 {
283     int result = FALSE;
284 
285     T((T_CALLED("_nc_reset_colors(%p)"), (void *) SP_PARM));
286     if (SP_PARM->_color_defs > 0)
287 	SP_PARM->_color_defs = -(SP_PARM->_color_defs);
288     if (reset_color_pair(NCURSES_SP_ARG))
289 	result = TRUE;
290 
291 #ifdef USE_TERM_DRIVER
292     result = CallDriver(SP_PARM, rescolors);
293 #else
294     if (orig_colors != 0) {
295 	TPUTS_TRACE("orig_colors");
296 	putp(orig_colors);
297 	result = TRUE;
298     }
299 #endif
300     returnBool(result);
301 }
302 
303 #if NCURSES_SP_FUNCS
304 NCURSES_EXPORT(bool)
305 _nc_reset_colors(void)
306 {
307     return NCURSES_SP_NAME(_nc_reset_colors) (CURRENT_SCREEN);
308 }
309 #endif
310 
311 NCURSES_EXPORT(int)
312 NCURSES_SP_NAME(start_color) (NCURSES_SP_DCL0)
313 {
314     int result = ERR;
315     int maxpairs = 0, maxcolors = 0;
316 
317     T((T_CALLED("start_color(%p)"), (void *) SP_PARM));
318 
319     if (SP_PARM == 0) {
320 	result = ERR;
321     } else if (SP_PARM->_coloron) {
322 	result = OK;
323     } else {
324 	maxpairs = MaxPairs;
325 	maxcolors = MaxColors;
326 	if (reset_color_pair(NCURSES_SP_ARG) != TRUE) {
327 	    set_foreground_color(NCURSES_SP_ARGx
328 				 default_fg(NCURSES_SP_ARG),
329 				 NCURSES_SP_NAME(_nc_outch));
330 	    set_background_color(NCURSES_SP_ARGx
331 				 default_bg(NCURSES_SP_ARG),
332 				 NCURSES_SP_NAME(_nc_outch));
333 	}
334 
335 	if (maxpairs > 0 && maxcolors > 0) {
336 	    SP_PARM->_pair_limit = maxpairs;
337 
338 #if NCURSES_EXT_FUNCS
339 	    /*
340 	     * If using default colors, allocate extra space in table to
341 	     * allow for default-color as a component of a color-pair.
342 	     */
343 	    SP_PARM->_pair_limit += (1 + (2 * maxcolors));
344 #endif
345 	    SP_PARM->_pair_count = maxpairs;
346 	    SP_PARM->_color_count = maxcolors;
347 #if !USE_REENTRANT
348 	    COLOR_PAIRS = maxpairs;
349 	    COLORS = maxcolors;
350 #endif
351 
352 	    SP_PARM->_color_pairs = TYPE_CALLOC(colorpair_t, SP_PARM->_pair_limit);
353 	    if (SP_PARM->_color_pairs != 0) {
354 		SP_PARM->_color_table = TYPE_CALLOC(color_t, maxcolors);
355 		if (SP_PARM->_color_table != 0) {
356 		    SP_PARM->_color_pairs[0] = PAIR_OF(default_fg(NCURSES_SP_ARG),
357 						       default_bg(NCURSES_SP_ARG));
358 		    init_color_table(NCURSES_SP_ARG);
359 
360 		    T(("started color: COLORS = %d, COLOR_PAIRS = %d",
361 		       COLORS, COLOR_PAIRS));
362 
363 		    SP_PARM->_coloron = 1;
364 		    result = OK;
365 		} else if (SP_PARM->_color_pairs != 0) {
366 		    FreeAndNull(SP_PARM->_color_pairs);
367 		}
368 	    }
369 	} else {
370 	    result = OK;
371 	}
372     }
373     returnCode(result);
374 }
375 
376 #if NCURSES_SP_FUNCS
377 NCURSES_EXPORT(int)
378 start_color(void)
379 {
380     return NCURSES_SP_NAME(start_color) (CURRENT_SCREEN);
381 }
382 #endif
383 
384 /* This function was originally written by Daniel Weaver <danw@znyx.com> */
385 static void
386 rgb2hls(short r, short g, short b, short *h, short *l, short *s)
387 /* convert RGB to HLS system */
388 {
389     short min, max, t;
390 
391     if ((min = g < r ? g : r) > b)
392 	min = b;
393     if ((max = g > r ? g : r) < b)
394 	max = b;
395 
396     /* calculate lightness */
397     *l = (short) ((min + max) / 20);
398 
399     if (min == max) {		/* black, white and all shades of gray */
400 	*h = 0;
401 	*s = 0;
402 	return;
403     }
404 
405     /* calculate saturation */
406     if (*l < 50)
407 	*s = (short) (((max - min) * 100) / (max + min));
408     else
409 	*s = (short) (((max - min) * 100) / (2000 - max - min));
410 
411     /* calculate hue */
412     if (r == max)
413 	t = (short) (120 + ((g - b) * 60) / (max - min));
414     else if (g == max)
415 	t = (short) (240 + ((b - r) * 60) / (max - min));
416     else
417 	t = (short) (360 + ((r - g) * 60) / (max - min));
418 
419     *h = t % 360;
420 }
421 
422 /*
423  * Extension (1997/1/18) - Allow negative f/b values to set default color
424  * values.
425  */
426 NCURSES_EXPORT(int)
427 NCURSES_SP_NAME(init_pair) (NCURSES_SP_DCLx short pair, short f, short b)
428 {
429     colorpair_t result;
430     colorpair_t previous;
431     int maxcolors;
432 
433     T((T_CALLED("init_pair(%p,%d,%d,%d)"), (void *) SP_PARM, pair, f, b));
434 
435     if (!ValidPair(pair))
436 	returnCode(ERR);
437 
438     maxcolors = MaxColors;
439 
440     previous = SP_PARM->_color_pairs[pair];
441 #if NCURSES_EXT_FUNCS
442     if (SP_PARM->_default_color) {
443 	bool isDefault = FALSE;
444 	bool wasDefault = FALSE;
445 	int default_pairs = SP_PARM->_default_pairs;
446 
447 	/*
448 	 * Map caller's color number, e.g., -1, 0, 1, .., 7, etc., into
449 	 * internal unsigned values which we will store in the _color_pairs[]
450 	 * table.
451 	 */
452 	if (isDefaultColor(f)) {
453 	    f = COLOR_DEFAULT;
454 	    isDefault = TRUE;
455 	} else if (!OkColorHi(f)) {
456 	    returnCode(ERR);
457 	}
458 
459 	if (isDefaultColor(b)) {
460 	    b = COLOR_DEFAULT;
461 	    isDefault = TRUE;
462 	} else if (!OkColorHi(b)) {
463 	    returnCode(ERR);
464 	}
465 
466 	/*
467 	 * Check if the table entry that we are going to init/update used
468 	 * default colors.
469 	 */
470 	if ((FORE_OF(previous) == COLOR_DEFAULT)
471 	    || (BACK_OF(previous) == COLOR_DEFAULT))
472 	    wasDefault = TRUE;
473 
474 	/*
475 	 * Keep track of the number of entries in the color pair table which
476 	 * used a default color.
477 	 */
478 	if (isDefault && !wasDefault) {
479 	    ++default_pairs;
480 	} else if (wasDefault && !isDefault) {
481 	    --default_pairs;
482 	}
483 
484 	/*
485 	 * As an extension, ncurses allows the pair number to exceed the
486 	 * terminal's color_pairs value for pairs using a default color.
487 	 *
488 	 * Note that updating a pair which used a default color with one
489 	 * that does not will decrement the count - and possibly interfere
490 	 * with sequentially adding new pairs.
491 	 */
492 	if (pair > (SP_PARM->_pair_count + default_pairs)) {
493 	    returnCode(ERR);
494 	}
495 	SP_PARM->_default_pairs = default_pairs;
496     } else
497 #endif
498     {
499 	if ((f < 0) || !OkColorHi(f)
500 	    || (b < 0) || !OkColorHi(b)
501 	    || (pair < 1))
502 	    returnCode(ERR);
503     }
504 
505     /*
506      * When a pair's content is changed, replace its colors (if pair was
507      * initialized before a screen update is performed replacing original
508      * pair colors with the new ones).
509      */
510     result = PAIR_OF(f, b);
511     if (previous != 0
512 	&& previous != result) {
513 	int y, x;
514 
515 	for (y = 0; y <= CurScreen(SP_PARM)->_maxy; y++) {
516 	    struct ldat *ptr = &(CurScreen(SP_PARM)->_line[y]);
517 	    bool changed = FALSE;
518 	    for (x = 0; x <= CurScreen(SP_PARM)->_maxx; x++) {
519 		if (GetPair(ptr->text[x]) == pair) {
520 		    /* Set the old cell to zero to ensure it will be
521 		       updated on the next doupdate() */
522 		    SetChar(ptr->text[x], 0, 0);
523 		    CHANGED_CELL(ptr, x);
524 		    changed = TRUE;
525 		}
526 	    }
527 	    if (changed)
528 		NCURSES_SP_NAME(_nc_make_oldhash) (NCURSES_SP_ARGx y);
529 	}
530     }
531 
532     SP_PARM->_color_pairs[pair] = result;
533     if (GET_SCREEN_PAIR(SP_PARM) == pair)
534 	SET_SCREEN_PAIR(SP_PARM, (chtype) (~0));	/* force attribute update */
535 
536 #ifdef USE_TERM_DRIVER
537     CallDriver_3(SP_PARM, initpair, pair, f, b);
538 #else
539     if (initialize_pair && InPalette(f) && InPalette(b)) {
540 	const color_t *tp = DefaultPalette;
541 
542 	TR(TRACE_ATTRS,
543 	   ("initializing pair: pair = %d, fg=(%d,%d,%d), bg=(%d,%d,%d)",
544 	    pair,
545 	    tp[f].red, tp[f].green, tp[f].blue,
546 	    tp[b].red, tp[b].green, tp[b].blue));
547 
548 	TPUTS_TRACE("initialize_pair");
549 	putp(TPARM_7(initialize_pair,
550 		     pair,
551 		     tp[f].red, tp[f].green, tp[f].blue,
552 		     tp[b].red, tp[b].green, tp[b].blue));
553     }
554 #endif
555 
556     returnCode(OK);
557 }
558 
559 #if NCURSES_SP_FUNCS
560 NCURSES_EXPORT(int)
561 init_pair(short pair, short f, short b)
562 {
563     return NCURSES_SP_NAME(init_pair) (CURRENT_SCREEN, pair, f, b);
564 }
565 #endif
566 
567 #define okRGB(n) ((n) >= 0 && (n) <= 1000)
568 
569 NCURSES_EXPORT(int)
570 NCURSES_SP_NAME(init_color) (NCURSES_SP_DCLx
571 			     short color, short r, short g, short b)
572 {
573     int result = ERR;
574     int maxcolors;
575 
576     T((T_CALLED("init_color(%p,%d,%d,%d,%d)"),
577        (void *) SP_PARM,
578        color,
579        r, g, b));
580 
581     if (SP_PARM == 0)
582 	returnCode(result);
583 
584     maxcolors = MaxColors;
585 
586     if (InitColor
587 	&& SP_PARM->_coloron
588 	&& (color >= 0 && OkColorHi(color))
589 	&& (okRGB(r) && okRGB(g) && okRGB(b))) {
590 
591 	SP_PARM->_color_table[color].init = 1;
592 	SP_PARM->_color_table[color].r = r;
593 	SP_PARM->_color_table[color].g = g;
594 	SP_PARM->_color_table[color].b = b;
595 
596 	if (UseHlsPalette) {
597 	    rgb2hls(r, g, b,
598 		    &SP_PARM->_color_table[color].red,
599 		    &SP_PARM->_color_table[color].green,
600 		    &SP_PARM->_color_table[color].blue);
601 	} else {
602 	    SP_PARM->_color_table[color].red = r;
603 	    SP_PARM->_color_table[color].green = g;
604 	    SP_PARM->_color_table[color].blue = b;
605 	}
606 
607 #ifdef USE_TERM_DRIVER
608 	CallDriver_4(SP_PARM, initcolor, color, r, g, b);
609 #else
610 	TPUTS_TRACE("initialize_color");
611 	putp(TPARM_4(initialize_color, color, r, g, b));
612 #endif
613 	SP_PARM->_color_defs = max(color + 1, SP_PARM->_color_defs);
614 
615 	result = OK;
616     }
617     returnCode(result);
618 }
619 
620 #if NCURSES_SP_FUNCS
621 NCURSES_EXPORT(int)
622 init_color(short color, short r, short g, short b)
623 {
624     return NCURSES_SP_NAME(init_color) (CURRENT_SCREEN, color, r, g, b);
625 }
626 #endif
627 
628 NCURSES_EXPORT(bool)
629 NCURSES_SP_NAME(can_change_color) (NCURSES_SP_DCL)
630 {
631     T((T_CALLED("can_change_color(%p)"), (void *) SP_PARM));
632     returnCode((CanChange != 0) ? TRUE : FALSE);
633 }
634 
635 #if NCURSES_SP_FUNCS
636 NCURSES_EXPORT(bool)
637 can_change_color(void)
638 {
639     return NCURSES_SP_NAME(can_change_color) (CURRENT_SCREEN);
640 }
641 #endif
642 
643 NCURSES_EXPORT(bool)
644 NCURSES_SP_NAME(has_colors) (NCURSES_SP_DCL0)
645 {
646     int code;
647 
648     (void) SP_PARM;
649     T((T_CALLED("has_colors()")));
650 #ifdef USE_TERM_DRIVER
651     code = HasColor;
652 #else
653     code = ((VALID_NUMERIC(max_colors) && VALID_NUMERIC(max_pairs)
654 	     && (((set_foreground != NULL)
655 		  && (set_background != NULL))
656 		 || ((set_a_foreground != NULL)
657 		     && (set_a_background != NULL))
658 		 || set_color_pair)) ? TRUE : FALSE);
659 #endif
660     returnCode(code);
661 }
662 
663 #if NCURSES_SP_FUNCS
664 NCURSES_EXPORT(bool)
665 has_colors(void)
666 {
667     return NCURSES_SP_NAME(has_colors) (CURRENT_SCREEN);
668 }
669 #endif
670 
671 NCURSES_EXPORT(int)
672 NCURSES_SP_NAME(color_content) (NCURSES_SP_DCLx
673 				short color, short *r, short *g, short *b)
674 {
675     int result = ERR;
676     int maxcolors;
677 
678     T((T_CALLED("color_content(%p,%d,%p,%p,%p)"),
679        (void *) SP_PARM,
680        color,
681        (void *) r,
682        (void *) g,
683        (void *) b));
684 
685     if (SP_PARM == 0)
686 	returnCode(result);
687 
688     maxcolors = MaxColors;
689 
690     if (color < 0 || !OkColorHi(color) || !SP_PARM->_coloron) {
691 	result = ERR;
692     } else {
693 	NCURSES_COLOR_T c_r = SP_PARM->_color_table[color].red;
694 	NCURSES_COLOR_T c_g = SP_PARM->_color_table[color].green;
695 	NCURSES_COLOR_T c_b = SP_PARM->_color_table[color].blue;
696 
697 	if (r)
698 	    *r = c_r;
699 	if (g)
700 	    *g = c_g;
701 	if (b)
702 	    *b = c_b;
703 
704 	TR(TRACE_ATTRS, ("...color_content(%d,%d,%d,%d)",
705 			 color, c_r, c_g, c_b));
706 	result = OK;
707     }
708     returnCode(result);
709 }
710 
711 #if NCURSES_SP_FUNCS
712 NCURSES_EXPORT(int)
713 color_content(short color, short *r, short *g, short *b)
714 {
715     return NCURSES_SP_NAME(color_content) (CURRENT_SCREEN, color, r, g, b);
716 }
717 #endif
718 
719 NCURSES_EXPORT(int)
720 NCURSES_SP_NAME(pair_content) (NCURSES_SP_DCLx
721 			       short pair, short *f, short *b)
722 {
723     int result;
724 
725     T((T_CALLED("pair_content(%p,%d,%p,%p)"),
726        (void *) SP_PARM,
727        pair,
728        (void *) f,
729        (void *) b));
730 
731     if (!ValidPair(pair)) {
732 	result = ERR;
733     } else {
734 	NCURSES_COLOR_T fg = FORE_OF(SP_PARM->_color_pairs[pair]);
735 	NCURSES_COLOR_T bg = BACK_OF(SP_PARM->_color_pairs[pair]);
736 
737 #if NCURSES_EXT_FUNCS
738 	if (fg == COLOR_DEFAULT)
739 	    fg = -1;
740 	if (bg == COLOR_DEFAULT)
741 	    bg = -1;
742 #endif
743 
744 	if (f)
745 	    *f = fg;
746 	if (b)
747 	    *b = bg;
748 
749 	TR(TRACE_ATTRS, ("...pair_content(%p,%d,%d,%d)",
750 			 (void *) SP_PARM,
751 			 pair,
752 			 fg, bg));
753 	result = OK;
754     }
755     returnCode(result);
756 }
757 
758 #if NCURSES_SP_FUNCS
759 NCURSES_EXPORT(int)
760 pair_content(short pair, short *f, short *b)
761 {
762     return NCURSES_SP_NAME(pair_content) (CURRENT_SCREEN, pair, f, b);
763 }
764 #endif
765 
766 NCURSES_EXPORT(void)
767 NCURSES_SP_NAME(_nc_do_color) (NCURSES_SP_DCLx
768 			       short old_pair,
769 			       short pair,
770 			       bool reverse,
771 			       NCURSES_SP_OUTC outc)
772 {
773 #ifdef USE_TERM_DRIVER
774     CallDriver_4(SP_PARM, docolor, old_pair, pair, reverse, outc);
775 #else
776     NCURSES_COLOR_T fg = COLOR_DEFAULT;
777     NCURSES_COLOR_T bg = COLOR_DEFAULT;
778     NCURSES_COLOR_T old_fg, old_bg;
779 
780     if (!ValidPair(pair)) {
781 	return;
782     } else if (pair != 0) {
783 	if (set_color_pair) {
784 	    TPUTS_TRACE("set_color_pair");
785 	    NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx
786 				    TPARM_1(set_color_pair, pair),
787 				    1, outc);
788 	    return;
789 	} else if (SP_PARM != 0) {
790 	    pair_content((short) pair, &fg, &bg);
791 	}
792     }
793 
794     if (old_pair >= 0
795 	&& SP_PARM != 0
796 	&& pair_content(old_pair, &old_fg, &old_bg) != ERR) {
797 	if ((isDefaultColor(fg) && !isDefaultColor(old_fg))
798 	    || (isDefaultColor(bg) && !isDefaultColor(old_bg))) {
799 #if NCURSES_EXT_FUNCS
800 	    /*
801 	     * A minor optimization - but extension.  If "AX" is specified in
802 	     * the terminal description, treat it as screen's indicator of ECMA
803 	     * SGR 39 and SGR 49, and assume the two sequences are independent.
804 	     */
805 	    if (SP_PARM->_has_sgr_39_49
806 		&& isDefaultColor(old_bg)
807 		&& !isDefaultColor(old_fg)) {
808 		NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx "\033[39m", 1, outc);
809 	    } else if (SP_PARM->_has_sgr_39_49
810 		       && isDefaultColor(old_fg)
811 		       && !isDefaultColor(old_bg)) {
812 		NCURSES_SP_NAME(tputs) (NCURSES_SP_ARGx "\033[49m", 1, outc);
813 	    } else
814 #endif
815 		reset_color_pair(NCURSES_SP_ARG);
816 	}
817     } else {
818 	reset_color_pair(NCURSES_SP_ARG);
819 	if (old_pair < 0)
820 	    return;
821     }
822 
823 #if NCURSES_EXT_FUNCS
824     if (isDefaultColor(fg))
825 	fg = (short) default_fg(NCURSES_SP_ARG);
826     if (isDefaultColor(bg))
827 	bg = (short) default_bg(NCURSES_SP_ARG);
828 #endif
829 
830     if (reverse) {
831 	NCURSES_COLOR_T xx = fg;
832 	fg = bg;
833 	bg = xx;
834     }
835 
836     TR(TRACE_ATTRS, ("setting colors: pair = %d, fg = %d, bg = %d", pair,
837 		     fg, bg));
838 
839     if (!isDefaultColor(fg)) {
840 	set_foreground_color(NCURSES_SP_ARGx fg, outc);
841     }
842     if (!isDefaultColor(bg)) {
843 	set_background_color(NCURSES_SP_ARGx bg, outc);
844     }
845 #endif
846 }
847 
848 #if NCURSES_SP_FUNCS
849 NCURSES_EXPORT(void)
850 _nc_do_color(short old_pair, short pair, bool reverse, NCURSES_OUTC outc)
851 {
852     SetSafeOutcWrapper(outc);
853     NCURSES_SP_NAME(_nc_do_color) (CURRENT_SCREEN,
854 				   old_pair,
855 				   pair,
856 				   reverse,
857 				   _nc_outc_wrapper);
858 }
859 #endif
860