about summary refs log tree commit diff
path: root/converter/pbm/pbmtocis.c
blob: 9bb42c56e9f2a323f33444beb4ef69b42f141d3f (plain) (blame)
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
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
/*
 *  cistopbm: Convert images in the CompuServe RLE format to PBM
 *  Copyright (C) 2009  John Elliott
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "pbm.h"

/* The maximum length of a run. Limit it to 0x5E bytes so that it is always
 * represented by a printable character 0x20-0x7E */
#define MAXRUNLENGTH 0x5E

static void syntax(const char *prog)
{
    pm_usage(" { options } { input } }\n\n"
         "Input file should be in PBM format.\n"
         "Output will be in CompuServe RLE format.\n"
         "Options:\n"
         "-i, --inverse: Reverse black and white.\n"
         "-w, --whitebg: White background.\n"
         "--:            End of options\n\n"
"pbmtocis v1.00, Copyright 2009 John Elliott <jce@seasip.demon.co.uk>\n"
"This program is redistributable under the terms of the GNU General Public\n"
"License, version 2 or later.\n"
         );
}

int main(int argc, const char **argv)
{
    FILE *ofP = stdout;
    FILE *ifP;
    int inoptions = 1;
    int n, x, y;
    int bg = PBM_BLACK; /* Default colouring is white on black */
    int inverse = 0;
    int cell, last, run;
    const char *inpname = NULL;

    int outh, outw;
    int height, width;
    bit **bits;

    pm_proginit(&argc, argv);

    for (n = 1; n < argc; n++)
    {
        if (!strcmp(argv[n], "--"))
        {
            inoptions = 0;
            continue;
        }
        if (inoptions)
        {
            if (pm_keymatch(argv[n], "-h", 2) ||
                pm_keymatch(argv[n], "-H", 2) ||
                pm_keymatch(argv[n], "--help", 6))
            {
                syntax(argv[0]);
                return EXIT_SUCCESS;
            }
            if (pm_keymatch(argv[n], "-i", 2) ||
                pm_keymatch(argv[n], "-I", 2) ||
                pm_keymatch(argv[n], "--inverse", 9))
            {
                inverse = 1;
                continue;
            }
            if (pm_keymatch(argv[n], "-w", 2) ||
                pm_keymatch(argv[n], "-W", 2) ||
                pm_keymatch(argv[n], "--whitebg", 9))
            {
                bg = PBM_WHITE; 
                continue;
            }
            if (argv[n][0] == '-' && argv[n][1] != 0)
            {
                pm_message("Unknown option: %s", argv[n]);
                syntax(argv[0]);
                return EXIT_FAILURE;
            }
        }

        if (inpname == NULL) inpname = argv[n];
        else { syntax(argv[0]); return EXIT_FAILURE; }
    }
    if (inpname == NULL) inpname = "-";
    ifP  = pm_openr(inpname);

    /* Load the PBM */
    bits = pbm_readpbm(ifP, &width, &height);

    if      (width <= 128 && height <= 96)  { outw = 128; outh = 96; }
    else if (width <= 256 && height <= 192) { outw = 256; outh = 192; }
    else
    {
        outw = 256;
        outh = 192;
        pm_message("Warning: Input file is larger than 256x192. "
                "It will be cropped.");
    }
    /* Write the magic number */
    fputc(0x1B, ofP);
    fputc(0x47, ofP);
    fputc((outw == 128) ? 0x4D : 0x48, ofP);

    /* And now start encoding */
    y = x = 0;
    last = PBM_BLACK;
    run = 0;
    while (y < outh)
    {
        if (x < width && y < height)    
        {
            cell = bits[y][x];
            if (inverse) cell ^= (PBM_BLACK ^ PBM_WHITE);
        }
        else cell = bg;

        if (cell == last)   /* Cell is part of current run */
        {
            ++run;
            if (run > MAXRUNLENGTH)
            {       
                fputc(0x20 + MAXRUNLENGTH, ofP);
                fputc(0x20, ofP);
                run -= MAXRUNLENGTH;
            }   
        }
        else    /* change */
        {
            fputc(run + 0x20, ofP);
            last = last ^ (PBM_BLACK ^ PBM_WHITE);
            run = 1;
        }
        ++x;
        if (x >= outw) { x = 0; ++y; }
    }
    if (last == bg) /* Last cell written was background. Write foreground */
    {
        fputc(run + 0x20, ofP);
    }
    else if (run)   /* Write background and foreground */
    {
        fputc(run + 0x20, ofP);
        fputc(0x20, ofP);
    }
    /* Write the end-graphics signature */
    fputc(0x1B, ofP);
    fputc(0x47, ofP);
    fputc(0x4E, ofP);
    pm_close(ifP);
    return 0;   
}