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
|
/* mgrtopbm.c - read a MGR bitmap and produce a portable bitmap
**
** Copyright (C) 1989 by Jef Poskanzer.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation. This software is provided "as is" without express or
** implied warranty.
*/
#include <string.h>
#include <errno.h>
#include "pbm.h"
#include "mgr.h"
static unsigned char item;
static int bitsperitem, bitshift;
static void
getinit(FILE * const file,
int * const colsP,
int * const rowsP,
int * const depthP,
int * const padrightP,
int * const bitsperitemP) {
struct b_header head;
int pad;
if (fread(&head, sizeof(struct old_b_header), 1, file ) != 1)
pm_error("Unable to read 1st byte of file. "
"fread() returns errno %d (%s)",
errno, strerror(errno));
if (head.magic[0] == 'y' && head.magic[1] == 'z') {
/* new style bitmap */
if (fread(&head.depth,
sizeof(head) - sizeof(struct old_b_header), 1, file)
!= 1 )
pm_error("Unable to read header after 1st byte. "
"fread() returns errno %d (%s)",
errno, strerror(errno));
*depthP = (int) head.depth - ' ';
pad = 8;
} else if (head.magic[0] == 'x' && head.magic[1] == 'z') {
/* old style bitmap with 32-bit padding */
*depthP = 1;
pad = 32;
} else if (head.magic[0] == 'z' && head.magic[1] == 'z') {
/* old style bitmap with 16-bit padding */
*depthP = 1;
pad = 16;
} else if (head.magic[0] == 'z' && head.magic[1] == 'y') {
/* old style 8-bit pixmap with 16-bit padding */
*depthP = 8;
pad = 16;
} else {
pm_error("bad magic chars in MGR file: '%c%c'",
head.magic[0], head.magic[1] );
pad = -1; /* should never reach here */
}
if (head.h_wide < ' ' || head.l_wide < ' ')
pm_error("Invalid width field in MGR header");
if (head.h_high < ' ' || head.l_high < ' ')
pm_error("Invalid width field in MGR header");
*colsP = (((int)head.h_wide - ' ') << 6) + ((int)head.l_wide - ' ');
*rowsP = (((int)head.h_high - ' ') << 6) + ((int) head.l_high - ' ');
*padrightP = ( ( *colsP + pad - 1 ) / pad ) * pad - *colsP;
*bitsperitemP = 8;
}
static bit
getbit( file )
FILE* file;
{
bit b;
if ( bitsperitem == 8 )
{
item = getc( file );
bitsperitem = 0;
bitshift = 7;
}
bitsperitem++;
b = ( ( item >> bitshift) & 1 ) ? PBM_BLACK : PBM_WHITE;
bitshift--;
return b;
}
int
main( argc, argv )
int argc;
char* argv[];
{
FILE* ifp;
bit* bitrow;
register bit* bP;
int rows, cols, depth, padright, row, col;
pbm_init( &argc, argv );
if ( argc > 2 )
pm_usage( "[mgrfile]" );
if ( argc == 2 )
ifp = pm_openr( argv[1] );
else
ifp = stdin;
getinit( ifp, &cols, &rows, &depth, &padright, &bitsperitem );
if ( depth != 1 )
pm_error( "MGR file has depth of %d, must be 1", depth );
pbm_writepbminit( stdout, cols, rows, 0 );
bitrow = pbm_allocrow( cols );
for ( row = 0; row < rows; row++ )
{
/* Get data, bit-reversed within each byte. */
for ( col = 0, bP = bitrow; col < cols; col++, bP++ )
*bP = getbit( ifp );
/* Discard line padding */
for ( col = 0; col < padright; col ++ )
(void) getbit( ifp );
pbm_writepbmrow( stdout, bitrow, cols, 0 );
}
pm_close( ifp );
pm_close( stdout );
exit( 0 );
}
|
