summaryrefslogtreecommitdiff
path: root/backend/dvi/mdvi-lib/color.c
blob: ef6036a9ef84613a1b2ca56464d0482119caf22d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
/*
 * Copyright (C) 2000, Matias Atria
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include <config.h>
#include "mdvi.h"
#include "color.h"

void	mdvi_set_color(DviContext *dvi, Ulong fg, Ulong bg)
{
	if(dvi->curr_fg != fg || dvi->curr_bg != bg) {
		DEBUG((DBG_DEVICE, "setting color to (%lu,%lu)\n", fg, bg));
		if(dvi->device.set_color)
			dvi->device.set_color(dvi->device.device_data, fg, bg);
		dvi->curr_fg = fg;
		dvi->curr_bg = bg;
	}
}

void	mdvi_push_color(DviContext *dvi, Ulong fg, Ulong bg)
{
	if(dvi->color_top == dvi->color_size) {
		dvi->color_size += 32;
		dvi->color_stack = mdvi_realloc(dvi->color_stack,
			dvi->color_size * sizeof(DviColorPair));
	}
	dvi->color_stack[dvi->color_top].fg = dvi->curr_fg;
	dvi->color_stack[dvi->color_top].bg = dvi->curr_bg;
	dvi->color_top++;
	mdvi_set_color(dvi, fg, bg);
}

void	mdvi_pop_color(DviContext *dvi)
{
	Ulong	fg, bg;

	if(dvi->color_top == 0)
		return;
	dvi->color_top--;
	fg = dvi->color_stack[dvi->color_top].fg;
	bg = dvi->color_stack[dvi->color_top].bg;
	mdvi_set_color(dvi, fg, bg);
}

void	mdvi_reset_color(DviContext *dvi)
{
	dvi->color_top = 0;
	mdvi_set_color(dvi, dvi->params.fg, dvi->params.bg);
}

/* cache for color tables, to avoid creating them for every glyph */
typedef struct {
	Ulong	fg;
	Ulong	bg;
	Uint	nlevels;
	Ulong	*pixels;
	int	density;
	double	gamma;
	Uint	hits;
} ColorCache;

#define CCSIZE		256
static ColorCache	color_cache[CCSIZE];
static int		cc_entries;

#define GAMMA_DIFF	0.005


/* create a color table */
Ulong	*get_color_table(DviDevice *dev,
			 int nlevels, Ulong fg, Ulong bg, double gamma, int density)
{
	ColorCache	*cc, *tofree;
	int		lohits;
	Ulong		*pixels;
	int		status;

	lohits = color_cache[0].hits;
	tofree = &color_cache[0];
	/* look in the cache and see if we have one that matches this request */
	for(cc = &color_cache[0]; cc < &color_cache[cc_entries]; cc++) {
		if(cc->hits < lohits) {
			lohits = cc->hits;
			tofree = cc;
		}
		if(cc->fg == fg && cc->bg == bg && cc->density == density &&
		   cc->nlevels == nlevels && fabs(cc->gamma - gamma) <= GAMMA_DIFF)
		   	break;
	}

	if(cc < &color_cache[cc_entries]) {
		cc->hits++;
		return cc->pixels;
	}

	DEBUG((DBG_DEVICE, "Adding color table to cache (fg=%lu, bg=%lu, n=%d)\n",
		fg, bg, nlevels));

	/* no entry was found in the cache, create a new one */
	if(cc_entries < CCSIZE) {
		cc = &color_cache[cc_entries++];
		cc->pixels = NULL;
	} else {
		cc = tofree;
		mdvi_free(cc->pixels);
	}
	pixels = xnalloc(Ulong, nlevels);
	status = dev->alloc_colors(dev->device_data,
		pixels, nlevels, fg, bg, gamma, density);
	if(status < 0) {
		mdvi_free(pixels);
		return NULL;
	}
	cc->fg = fg;
	cc->bg = bg;
	cc->gamma = gamma;
	cc->density = density;
	cc->nlevels = nlevels;
	cc->pixels = pixels;
	cc->hits = 1;
	return pixels;
}