summaryrefslogtreecommitdiff
path: root/glabels2/barcode-0.98/plessey.c
blob: ec4710058ed8a87d07086d76d9863b71ae919400 (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
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
/*
 * plessey.c -- encoding for Plessey
 *
 * Copyright (c) 2000 Leonid A. Broukhis (leob@mailcom.com)
 *
 *   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 <ctype.h>
#include <errno.h>

#include "barcode.h"

static char * patterns[] = { "13", "31" };

/* this is ordered in decades to simplify encoding */
static char alphabet[] = 
   "0123456789" "ABCDEF";

/* stop sequence may be 231311313 (barcodemill.com) */
static char *fillers[] = { "031311331", "331311313" };

static int width = 16, startpos = 16;

/*
 * Check that the text can be encoded. Returns 0 or -1.
 * If it's all lowecase convert to uppercase and accept it
 */
int Barcode_pls_verify(unsigned char *text)
{
    int i, upper = 0, lower = 0;

    if (!strlen(text))
	return -1;
    for (i=0; text[i]; i++) {
        if (!strchr(alphabet,toupper(text[i])))
            return -1;
	if (isupper(text[i])) upper++;
	if (islower(text[i])) lower++;
    }
    if (upper && lower)
	return -1;
    return 0;
}

static int add_one(char *ptr, int code)
{
    sprintf(ptr, "%s%s%s%s", 
	patterns[code & 1],
	patterns[(code >> 1) & 1],
	patterns[(code >> 2) & 1],
	patterns[(code >> 3) & 1]
    );
    return 0;
}

/*
 * The encoding functions fills the "partial" and "textinfo" fields.
 * Lowercase chars are converted to uppercase
 */
int Barcode_pls_encode(struct Barcode_Item *bc)
{
    static char *text;
    static char *partial;  /* dynamic */
    static char *textinfo; /* dynamic */
    char *c, *ptr, *textptr;
    unsigned char *checkptr;
    int i, code, textpos;
    static char check[9] = {1,1,1,1,0,1,0,0,1};
    if (bc->partial)
	free(bc->partial);
    if (bc->textinfo)
	free(bc->textinfo);
    bc->partial = bc->textinfo = NULL; /* safe */

    if (!bc->encoding)
	bc->encoding = strdup("plessey");

    text = bc->ascii;
    if (!text) {
        bc->error = EINVAL;
        return -1;
    }
    /* the partial code is 8 * (head + text + check + tail) + margin + term. */
    partial = malloc( (strlen(text) + 4) * 8 + 3);
    checkptr = calloc (1, strlen(text) * 4 + 8);

    if (!partial || !checkptr) {
	if (partial) free(partial);
	if (checkptr) free(checkptr);
        bc->error = errno;
        return -1;
    }

    /* the text information is at most "nnn:fff:c " * strlen +term */
    textinfo = malloc(10*strlen(text) + 2);
    if (!textinfo) {
        bc->error = errno;
        free(partial);
        return -1;
    }

    strcpy(partial, fillers[0]);
    ptr = partial + strlen(partial);
    textptr = textinfo;
    textpos = startpos;
    
    for (i=0; i<strlen(text); i++) {
        c = strchr(alphabet, toupper(text[i]));
        if (!c) {
            bc->error = EINVAL; /* impossible if text is verified */
            free(partial);
            free(textinfo);
            return -1;
        }
        code = c - alphabet;
        add_one(ptr, code);
        sprintf(textptr, "%i:12:%c ", textpos, toupper(text[i]));
        
        textpos += width; /* width of each code */
        textptr += strlen(textptr);
        ptr += strlen(ptr); 
	checkptr[4*i] = code & 1;
	checkptr[4*i+1] = (code >> 1) & 1;
	checkptr[4*i+2] = (code >> 2) & 1;
	checkptr[4*i+3] = (code >> 3) & 1;
    }
    /* The CRC checksum is required */
    for (i=0; i < 4*strlen(text); i++) {
        int j;
        if (checkptr[i])
                for (j = 0; j < 9; j++)
                        checkptr[i+j] ^= check[j];
    }
    for (i = 0; i < 8; i++) {
        sprintf(ptr, patterns[checkptr[strlen(text) * 4 + i]]);
	ptr += 2;
    }
    fprintf(stderr, "CRC: ");
    for (i = 0; i < 8; i++) {
        fputc('0' + checkptr[strlen(text) * 4 + i], stderr);
    }
    fputc('\n', stderr);
    strcpy(ptr, fillers[1]);
    bc->partial = partial;
    bc->textinfo = textinfo;

    return 0;
}