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
|
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include <err.h>
#define MAX(x, y) (((x) > (y)) ? (x) : (y))
enum cmd {
CMD_INIT,
CMD_PRINTABLE_WIDTH,
CMD_RASTER_MODE_START,
CMD_RASTER_PAGE_LENGTH,
CMD_START_PAGE,
CMD_END_PAGE,
CMD_END_JOB,
};
static void
putcmd(FILE *f, const enum cmd cmd)
{
assert(f);
const struct {
const uint8_t *bytes;
size_t len;
} map[] = {
#define CMD(...) { .bytes = (uint8_t[]){__VA_ARGS__ }, .len = sizeof((uint8_t[]){__VA_ARGS__}) }
CMD(0x1b, '@'),
CMD(0x1b, 0x1e, 'A', 0x00),
CMD(0x1b, '*', 'r', 'R', 0x1b, '*', 'r', 'A'),
CMD(0x1b, '*', 'r', 'P', '0', 0x00),
CMD(0x00),
CMD(0x1b, '*', 'r', 'Y', '1', 0x00, 0x1b, 0x0c),
CMD(0x04, 0x1b, '*', 'r', 'B'),
#undef CMD
};
if (fwrite(map[cmd].bytes, 1, map[cmd].len, f) != map[cmd].len)
err(EXIT_FAILURE, "fwrite");
}
static FILE*
fopen_or_die(const char *path, const char *mode)
{
assert(path && mode);
FILE *f;
if (!(f = fopen(path, mode)))
err(EXIT_FAILURE, "fopen(%s, %s)", path, mode);
return f;
}
static uint8_t*
find_pixel_not_rev(const uint8_t *data, const size_t len, const uint8_t pixel)
{
for (const uint8_t *p = data + MAX(len, 1) - 1; p != data; --p) {
if (*p != pixel)
return (uint8_t*)p;
}
return NULL;
}
uint8_t*
pixels_from_pbm(FILE *f, size_t *out_w, size_t *out_h)
{
uint8_t magic[3];
if (fread(magic, 1, sizeof(magic), f) != sizeof(magic))
return NULL;
if (memcmp(magic, "P4", 2) || !isspace(magic[2]))
errx(EXIT_FAILURE, "not a valid pbm (P4) file");
uint32_t cfg[2];
for (uint8_t i = 0; i < sizeof(cfg) / sizeof(cfg[0]); ++i) {
char buf[32];
size_t x = 0;
do {
if (fread(buf + x, 1, 1, f) != 1)
err(EXIT_FAILURE, "fread");
} while (!isspace(buf[x]) && ++x < sizeof(buf));
if (!isspace(buf[x]))
errx(EXIT_FAILURE, "not a valid pbm (P4) file");
cfg[i] = strtol(buf, NULL, 10);
}
if (!cfg[0] || !cfg[1])
errx(EXIT_FAILURE, "invalid width / height");
uint8_t *bw;
#define div_round_up(x, y) (1 + ((x - 1) / y))
const size_t bw_sz = div_round_up(cfg[0], 8) * cfg[1];
if (!(bw = calloc(bw_sz, 1)))
err(EXIT_FAILURE, "calloc");
for (size_t read = 0, r; read < bw_sz; read += r) {
if (!(r = fread(bw + read, 1, bw_sz - read, f)))
errx(EXIT_FAILURE, "fread");
}
*out_w = div_round_up(cfg[0], 8), *out_h = cfg[1];
return bw;
}
int
main(int argc, char *argv[])
{
FILE *input = (argc >= 2 ? fopen_or_die(argv[1], "rb") : stdin);
FILE *output = (argc >= 3 ? fopen_or_die(argv[2], "wb") : stdout);
putcmd(output, CMD_INIT);
putcmd(output, CMD_PRINTABLE_WIDTH);
putcmd(output, CMD_RASTER_MODE_START);
putcmd(output, CMD_RASTER_PAGE_LENGTH);
size_t w, h;
uint8_t *pixels;
while ((pixels = pixels_from_pbm(input, &w, &h))) {
putcmd(output, CMD_START_PAGE);
size_t blank = 0;
for (size_t y = 0; y < h; ++y) {
const uint8_t *last_black;
if (!(last_black = find_pixel_not_rev(&pixels[y * w], w, 0))) {
++blank;
continue;
}
if (blank) {
fprintf(output, "\x01b*rY%zu%c", blank, 0);
blank = 0;
}
const size_t pos = (last_black - &pixels[y * w]) + 1;
assert(y * w + pos <= w * h);
fprintf(output, "b%c%c", (char)(pos % 256), (char)(pos / 256));
fwrite(&pixels[y * w], 1, pos, output);
}
putcmd(output, CMD_END_PAGE);
free(pixels);
}
putcmd(output, CMD_END_JOB);
return EXIT_SUCCESS;
}
|
