1 /*
2 * Copyright (C) 2000, Matias Atria
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
17 */
18
19 #include <config.h>
20 #include "mdvi.h"
21 #include "color.h"
22
mdvi_set_color(DviContext * dvi,Ulong fg,Ulong bg)23 void mdvi_set_color(DviContext *dvi, Ulong fg, Ulong bg)
24 {
25 if(dvi->curr_fg != fg || dvi->curr_bg != bg) {
26 DEBUG((DBG_DEVICE, "setting color to (%lu,%lu)\n", fg, bg));
27 if(dvi->device.set_color)
28 dvi->device.set_color(dvi->device.device_data, fg, bg);
29 dvi->curr_fg = fg;
30 dvi->curr_bg = bg;
31 }
32 }
33
mdvi_push_color(DviContext * dvi,Ulong fg,Ulong bg)34 void mdvi_push_color(DviContext *dvi, Ulong fg, Ulong bg)
35 {
36 if(dvi->color_top == dvi->color_size) {
37 dvi->color_size += 32;
38 dvi->color_stack = mdvi_realloc(dvi->color_stack,
39 dvi->color_size * sizeof(DviColorPair));
40 }
41 dvi->color_stack[dvi->color_top].fg = dvi->curr_fg;
42 dvi->color_stack[dvi->color_top].bg = dvi->curr_bg;
43 dvi->color_top++;
44 mdvi_set_color(dvi, fg, bg);
45 }
46
mdvi_pop_color(DviContext * dvi)47 void mdvi_pop_color(DviContext *dvi)
48 {
49 Ulong fg, bg;
50
51 if(dvi->color_top == 0)
52 return;
53 dvi->color_top--;
54 fg = dvi->color_stack[dvi->color_top].fg;
55 bg = dvi->color_stack[dvi->color_top].bg;
56 mdvi_set_color(dvi, fg, bg);
57 }
58
mdvi_reset_color(DviContext * dvi)59 void mdvi_reset_color(DviContext *dvi)
60 {
61 dvi->color_top = 0;
62 mdvi_set_color(dvi, dvi->params.fg, dvi->params.bg);
63 }
64
65 /* cache for color tables, to avoid creating them for every glyph */
66 typedef struct {
67 Ulong fg;
68 Ulong bg;
69 Uint nlevels;
70 Ulong *pixels;
71 int density;
72 double gamma;
73 Uint hits;
74 } ColorCache;
75
76 #define CCSIZE 256
77 static ColorCache color_cache[CCSIZE];
78 static int cc_entries;
79
80 #define GAMMA_DIFF 0.005
81
82
83 /* create a color table */
get_color_table(DviDevice * dev,int nlevels,Ulong fg,Ulong bg,double gamma,int density)84 Ulong *get_color_table(DviDevice *dev,
85 int nlevels, Ulong fg, Ulong bg, double gamma, int density)
86 {
87 ColorCache *cc, *tofree;
88 int lohits;
89 Ulong *pixels;
90 int status;
91
92 lohits = color_cache[0].hits;
93 tofree = &color_cache[0];
94 /* look in the cache and see if we have one that matches this request */
95 for(cc = &color_cache[0]; cc < &color_cache[cc_entries]; cc++) {
96 if(cc->hits < lohits) {
97 lohits = cc->hits;
98 tofree = cc;
99 }
100 if(cc->fg == fg && cc->bg == bg && cc->density == density &&
101 cc->nlevels == nlevels && fabs(cc->gamma - gamma) <= GAMMA_DIFF)
102 break;
103 }
104
105 if(cc < &color_cache[cc_entries]) {
106 cc->hits++;
107 return cc->pixels;
108 }
109
110 DEBUG((DBG_DEVICE, "Adding color table to cache (fg=%lu, bg=%lu, n=%d)\n",
111 fg, bg, nlevels));
112
113 /* no entry was found in the cache, create a new one */
114 if(cc_entries < CCSIZE) {
115 cc = &color_cache[cc_entries++];
116 cc->pixels = NULL;
117 } else {
118 cc = tofree;
119 mdvi_free(cc->pixels);
120 }
121 pixels = xnalloc(Ulong, nlevels);
122 status = dev->alloc_colors(dev->device_data,
123 pixels, nlevels, fg, bg, gamma, density);
124 if(status < 0) {
125 mdvi_free(pixels);
126 return NULL;
127 }
128 cc->fg = fg;
129 cc->bg = bg;
130 cc->gamma = gamma;
131 cc->density = density;
132 cc->nlevels = nlevels;
133 cc->pixels = pixels;
134 cc->hits = 1;
135 return pixels;
136 }
137