dos3d

view src/palman.c @ 1:0b7f840afe4a

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palette management
author John Tsiombikas <nuclear@member.fsf.org>
date Mon, 21 Nov 2011 08:35:58 +0200
parents
children c3e0bccd673e
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1 /*
2 256-color 3D graphics hack for real-mode DOS.
3 Copyright (C) 2011 John Tsiombikas <nuclear@member.fsf.org>
4
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation, either version 3 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
17 */
18
19 #include <string.h>
20 #include "palman.h"
21
22 #define MAX_COLORS 256
23 static struct palm_color colors[MAX_COLORS];
24 static int base_index[MAX_COLORS];
25
26 static struct palm_color pal[MAX_COLORS];
27 static unsigned int ncol, pcol;
28 static int range;
29
30 void palm_clear(void)
31 {
32 ncol = 0;
33 }
34
35 int palm_add_color(unsigned char r, unsigned char g, unsigned char b)
36 {
37 if(ncol >= MAX_COLORS) {
38 return -1;
39 }
40 colors[ncol].r = r;
41 colors[ncol].g = g;
42 colors[ncol].b = b;
43 ncol++;
44 return 0;
45 }
46
47 /* TODO: build an octree */
48 int palm_build(void)
49 {
50 int i, j;
51
52 /* gradient range for each color */
53 range = MAX_COLORS / ncol;
54
55 if(range == 1) {
56 memcpy(pal, colors, ncol * sizeof *pal);
57 return 0;
58 }
59 pcol = 0;
60
61 for(i=0; i<ncol; i++) {
62 unsigned int r, g, b, dr, dg, db;
63
64 base_index[i] = pcol;
65
66 dr = (colors[i].r << 8) / (range - 1);
67 dg = (colors[i].g << 8) / (range - 1);
68 db = (colors[i].b << 8) / (range - 1);
69
70 r = g = b = 0;
71 for(j=0; j<range; j++) {
72 pal[pcol].r = (unsigned char)(r >> 8);
73 pal[pcol].g = (unsigned char)(g >> 8);
74 pal[pcol].b = (unsigned char)(b >> 8);
75 pcol++;
76 r += dr;
77 g += dg;
78 b += db;
79 }
80 }
81 return pcol;
82 }
83
84 struct palm_color *palm_palette(void)
85 {
86 return pal;
87 }
88
89 int palm_palette_size(void)
90 {
91 return pcol;
92 }
93
94
95 int palm_color_base(unsigned char r, unsigned char g, unsigned char b)
96 {
97 int i;
98
99 for(i=0; i<pcol; i++) {
100 if(colors[i].r == r && colors[i].g == g && colors[i].b == b) {
101 return base_index[i];
102 }
103 }
104 return -1;
105 }
106
107 int palm_color_range(void)
108 {
109 return range;
110 }