path: root/lib/libcurses/base/lib_color.c

/*	$OpenBSD: lib_color.c,v 1.4 1999/11/28 17:49:53 millert Exp $	*/

/****************************************************************************
 * Copyright (c) 1998,1999 Free Software Foundation, Inc.                   *
 *                                                                          *
 * Permission is hereby granted, free of charge, to any person obtaining a  *
 * copy of this software and associated documentation files (the            *
 * "Software"), to deal in the Software without restriction, including      *
 * without limitation the rights to use, copy, modify, merge, publish,      *
 * distribute, distribute with modifications, sublicense, and/or sell       *
 * copies of the Software, and to permit persons to whom the Software is    *
 * furnished to do so, subject to the following conditions:                 *
 *                                                                          *
 * The above copyright notice and this permission notice shall be included  *
 * in all copies or substantial portions of the Software.                   *
 *                                                                          *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
 *                                                                          *
 * Except as contained in this notice, the name(s) of the above copyright   *
 * holders shall not be used in advertising or otherwise to promote the     *
 * sale, use or other dealings in this Software without prior written       *
 * authorization.                                                           *
 ****************************************************************************/

/****************************************************************************
 *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
 *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
 ****************************************************************************/

/* lib_color.c
 *
 * Handles color emulation of SYS V curses
 */

#include <curses.priv.h>

#include <term.h>

MODULE_ID("$From: lib_color.c,v 1.40 1999/11/27 22:24:18 tom Exp $")

/*
 * These should be screen structure members.  They need to be globals for
 * hystorical reasons.  So we assign them in start_color() and also in
 * set_term()'s screen-switching logic.
 */
int COLOR_PAIRS = 0;
int COLORS = 0;

/*
 * Given a RGB range of 0..1000, we'll normally set the individual values
 * to about 2/3 of the maximum, leaving full-range for bold/bright colors.
 */
#define RGB_ON  680
#define RGB_OFF 0

static const color_t cga_palette[] =
{
    /*  R		G		B */
	{RGB_OFF,	RGB_OFF,	RGB_OFF},	/* COLOR_BLACK */
	{RGB_ON,	RGB_OFF,	RGB_OFF},	/* COLOR_RED */
	{RGB_OFF,	RGB_ON,		RGB_OFF},	/* COLOR_GREEN */
	{RGB_ON,	RGB_ON,		RGB_OFF},	/* COLOR_YELLOW */
	{RGB_OFF,	RGB_OFF,	RGB_ON},	/* COLOR_BLUE */
	{RGB_ON,	RGB_OFF,	RGB_ON},	/* COLOR_MAGENTA */
	{RGB_OFF,	RGB_ON,		RGB_ON},	/* COLOR_CYAN */
	{RGB_ON,	RGB_ON,		RGB_ON},	/* COLOR_WHITE */
};
static const color_t hls_palette[] =
{
    /*  H	L	S */
	{0,	0,	0},	/* COLOR_BLACK */
	{120,	50,	100},	/* COLOR_RED */
	{240,	50,	100},	/* COLOR_GREEN */
	{180,	50,	100},	/* COLOR_YELLOW */
	{330,	50,	100},	/* COLOR_BLUE */
	{60,	50,	100},	/* COLOR_MAGENTA */
	{300,	50,	100},	/* COLOR_CYAN */
	{0,	50,	100},	/* COLOR_WHITE */
};

#ifdef NCURSES_EXT_FUNCS
static int
default_fg(void)
{
	return (SP->_default_fg >= 0) ? SP->_default_fg : COLOR_WHITE;
}

static int
default_bg(void)
{
	return (SP->_default_bg >= 0) ? SP->_default_bg : COLOR_BLACK;
}
#else
#define default_fg() COLOR_WHITE
#define default_bg() COLOR_BLACK
#endif

/*
 * SVr4 curses is known to interchange color codes (1,4) and (3,6), possibly
 * to maintain compatibility with a pre-ANSI scheme.  The same scheme is
 * also used in the FreeBSD syscons.
 */
static int toggled_colors(int c)
{
    if (c < 16) {
	static const int table[] =
		{ 0,  4,  2,  6,  1,  5,  3,  7,
		  8, 12, 10, 14,  9, 13, 11, 15};
	c = table[c];
    }
    return c;
}

static void set_background_color(int bg, int  (*outc)(int))
{
	if (set_a_background)
	{
	    TPUTS_TRACE("set_a_background");
	    tputs(tparm(set_a_background, bg), 1, outc);
	}
	else
	{
	    TPUTS_TRACE("set_background");
	    tputs(tparm(set_background, toggled_colors(bg)), 1, outc);
	}
}

static void set_foreground_color(int fg, int  (*outc)(int))
{
	if (set_a_foreground)
	{
	    TPUTS_TRACE("set_a_foreground");
	    tputs(tparm(set_a_foreground, fg), 1, outc);
	}
	else
	{
	    TPUTS_TRACE("set_foreground");
	    tputs(tparm(set_foreground, toggled_colors(fg)), 1, outc);
	}
}

static bool set_original_colors(void)
{
	if (orig_pair != 0) {
		TPUTS_TRACE("orig_pair");
		putp(orig_pair);
		return TRUE;
	}
	else if (orig_colors != NULL)
	{
		TPUTS_TRACE("orig_colors");
		putp(orig_colors);
		return TRUE;
	}
	return FALSE;
}

int start_color(void)
{
	int n;
	const color_t *tp;

	T((T_CALLED("start_color()")));

	if (set_original_colors() != TRUE)
	{
		set_foreground_color(default_fg(), _nc_outch);
		set_background_color(default_bg(), _nc_outch);
	}

	if (max_pairs != -1)
		COLOR_PAIRS = SP->_pair_count = max_pairs;
	else
		returnCode(ERR);
	if ((SP->_color_pairs = typeCalloc(unsigned short, max_pairs)) == 0)
		returnCode(ERR);
	SP->_color_pairs[0] = PAIR_OF(default_fg(), default_bg());
	if (max_colors != -1)
		COLORS = SP->_color_count = max_colors;
	else
		returnCode(ERR);
	SP->_coloron = 1;

	if ((SP->_color_table = typeMalloc(color_t, COLORS)) == 0)
		returnCode(ERR);
	tp = (hue_lightness_saturation) ? hls_palette : cga_palette;
	for (n = 0; n < COLORS; n++) {
		if (n < 8) {
			SP->_color_table[n] = tp[n];
		} else {
			SP->_color_table[n] = tp[n % 8];
			if (hue_lightness_saturation) {
				SP->_color_table[n].green = 100;
			} else {
				if (SP->_color_table[n].red)
					SP->_color_table[n].red = 1000;
				if (SP->_color_table[n].green)
					SP->_color_table[n].green = 1000;
				if (SP->_color_table[n].blue)
					SP->_color_table[n].blue = 1000;
			}
		}
	}

	T(("started color: COLORS = %d, COLOR_PAIRS = %d", COLORS, COLOR_PAIRS));

	returnCode(OK);
}

/* This function was originally written by Daniel Weaver <danw@znyx.com> */
static void rgb2hls(short r, short g, short b, short *h, short *l, short *s)
/* convert RGB to HLS system */
{
    short min, max, t;

    if ((min = g < r ? g : r) > b) min = b;
    if ((max = g > r ? g : r) < b) max = b;

    /* calculate lightness */
    *l = (min + max) / 20;

    if (min == max)		/* black, white and all shades of gray */
    {
	*h = 0;
	*s = 0;
	return;
    }

    /* calculate saturation */
    if (*l < 50)
	*s = ((max - min) * 100) / (max + min);
    else *s = ((max - min) * 100) / (2000 - max - min);

    /* calculate hue */
    if (r == max)
	t = 120 + ((g - b) * 60) / (max - min);
    else
	if (g == max)
	    t = 240 + ((b - r) * 60) / (max - min);
	else
	    t = 360 + ((r - g) * 60) / (max - min);

    *h = t % 360;
}

/*
 * Extension (1997/1/18) - Allow negative f/b values to set default color
 * values.
 */
int init_pair(short pair, short f, short b)
{
	unsigned result;

	T((T_CALLED("init_pair(%d,%d,%d)"), pair, f, b));

	if ((pair < 1) || (pair >= COLOR_PAIRS))
		returnCode(ERR);
#ifdef NCURSES_EXT_FUNCS
	if (SP->_default_color)
	{
		if (f < 0)
			f = C_MASK;
		if (b < 0)
			b = C_MASK;
		if (f >= COLORS && f != C_MASK)
			returnCode(ERR);
		if (b >= COLORS && b != C_MASK)
			returnCode(ERR);
	}
	else
#endif
	if ((f < 0) || (f >= COLORS)
	 || (b < 0) || (b >= COLORS))
		returnCode(ERR);

	/*
	 * When a pair's content is changed, replace its colors (if pair was
	 * initialized before a screen update is performed replacing original
	 * pair colors with the new ones).
	 */
	result = PAIR_OF(f,b);
	if (SP->_color_pairs[pair] != 0
	 && SP->_color_pairs[pair] != result) {
	    int y, x;
	    attr_t z = COLOR_PAIR(pair);

	    for (y = 0; y <= curscr->_maxy; y++) {
		struct ldat *ptr = &(curscr->_line[y]);
		bool changed = FALSE;
		for (x = 0; x <= curscr->_maxx; x++) {
		    if ((ptr->text[x] & A_COLOR) == z) {
			/* Set the old cell to zero to ensure it will be
			   updated on the next doupdate() */
			ptr->text[x] = 0;
			CHANGED_CELL(ptr,x);
			changed = TRUE;
		    }
		}
		if (changed)
			_nc_make_oldhash(y);
	    }
	}
	SP->_color_pairs[pair] = result;

	if (initialize_pair)
	{
	    const color_t *tp = hue_lightness_saturation ? hls_palette : cga_palette;

	    T(("initializing pair: pair = %d, fg=(%d,%d,%d), bg=(%d,%d,%d)",
	       pair,
	       tp[f].red, tp[f].green, tp[f].blue,
	       tp[b].red, tp[b].green, tp[b].blue));

	    if (initialize_pair)
	    {
		TPUTS_TRACE("initialize_pair");
		putp(tparm(initialize_pair,
			    pair,
			    tp[f].red, tp[f].green, tp[f].blue,
			    tp[b].red, tp[b].green, tp[b].blue));
	    }
	}

	returnCode(OK);
}

int init_color(short color, short r, short g, short b)
{
	T((T_CALLED("init_color(%d,%d,%d,%d)"), color, r, g, b));

	if (initialize_color == NULL)
		returnCode(ERR);

	if (color < 0 || color >= COLORS)
		returnCode(ERR);
	if (r < 0 || r > 1000 || g < 0 ||  g > 1000 || b < 0 || b > 1000)
		returnCode(ERR);

	if (hue_lightness_saturation)
	    rgb2hls(r, g, b,
		      &SP->_color_table[color].red,
		      &SP->_color_table[color].green,
		      &SP->_color_table[color].blue);
	else
	{
		SP->_color_table[color].red = r;
		SP->_color_table[color].green = g;
		SP->_color_table[color].blue = b;
	}

	if (initialize_color)
	{
		TPUTS_TRACE("initialize_color");
		putp(tparm(initialize_color, color, r, g, b));
	}
	returnCode(OK);
}

bool can_change_color(void)
{
	T((T_CALLED("can_change_color()")));
	returnCode ((can_change != 0) ? TRUE : FALSE);
}

bool has_colors(void)
{
	T((T_CALLED("has_colors()")));
	returnCode (((max_colors != -1) && (max_pairs != -1)
		     && (((set_foreground != NULL)
			  && (set_background != NULL))
			 || ((set_a_foreground != NULL)
			     && (set_a_background != NULL))
			 || set_color_pair)) ? TRUE : FALSE);
}

int color_content(short color, short *r, short *g, short *b)
{
    T((T_CALLED("color_content(%d,%p,%p,%p)"), color, r, g, b));
    if (color < 0 || color >= COLORS)
	returnCode(ERR);

    if (r) *r = SP->_color_table[color].red;
    if (g) *g = SP->_color_table[color].green;
    if (b) *b = SP->_color_table[color].blue;
    returnCode(OK);
}

int pair_content(short pair, short *f, short *b)
{
	T((T_CALLED("pair_content(%d,%p,%p)"), pair, f, b));

	if ((pair < 0) || (pair >= COLOR_PAIRS))
		returnCode(ERR);
	if (f) *f = ((SP->_color_pairs[pair] >> C_SHIFT) & C_MASK);
	if (b) *b =  (SP->_color_pairs[pair] & C_MASK);

	returnCode(OK);
}

void _nc_do_color(int pair, bool reverse, int (*outc)(int))
{
    short fg, bg;

    if (pair == 0)
    {
	if (
#ifdef NCURSES_EXT_FUNCS
	    !SP->_default_color ||
#endif
	    !set_original_colors())
	{
	    set_foreground_color(default_fg(), outc);
	    set_background_color(default_bg(), outc);
	}
    }
    else
    {
	if (set_color_pair)
	{
	    TPUTS_TRACE("set_color_pair");
	    tputs(tparm(set_color_pair, pair), 1, outc);
	}
	else
	{
	    pair_content(pair, &fg, &bg);
	    if (reverse) {
		short xx = fg;
		fg = bg;
		bg = xx;
	    }

	    T(("setting colors: pair = %d, fg = %d, bg = %d", pair, fg, bg));

	    if (fg == C_MASK || bg == C_MASK)
	    {
		if (set_original_colors() != TRUE)
		{
			if (fg == C_MASK)
				set_foreground_color(default_fg(), outc);
			if (bg == C_MASK)
				set_background_color(default_bg(), outc);
		}
	    }
	    if (fg != C_MASK)
	    {
		set_foreground_color(fg, outc);
	    }
	    if (bg != C_MASK)
	    {
		set_background_color(bg, outc);
	    }
	}
    }
}