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
|
/**
* scrotty — Screenshot program for Linux's TTY
*
* Copyright © 2014, 2015 Mattias Andrée (maandree@member.fsf.org)
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "common.h"
#include "kern.h"
#include "pnm.h"
/**
* Stop when `try_alt_fbpath` (in scrotty.c) reaches this value.
*/
const int alt_fbpath_limit = 2;
/**
* This is called if no framebuffer is found.
*
* It prints a message describing this condition
* and suggests how to resolve it.
*/
void
print_not_found_help (void)
{
fprintf (stderr, _("%s: Unable to find a framebuffer. "
"If you have a file named %s/MAKEDEV, "
"run it with '-d /dev/fb' as root, "
"or try running '%s'.\n"),
execname, DEVDIR, "mknod /dev/fb0 c 29 0 && chgrp video /dev/fb0");
}
/**
* Construct the path to a framebuffer device.
*
* @param pathbuf Ouput buffer for the path.
* @param altpath The index of the alternative path-pattern to use.
* @param fbno The index of the framebuffer.
*/
void
get_fbpath (char *pathbuf, int altpath, int fbno)
{
sprintf (pathbuf, "%s/fb%s%i", DEVDIR, (altpath ? "/" : ""), fbno);
}
/**
* Get the dimensions of a framebuffer.
*
* @param fbno The number of the framebuffer.
* @param fbpath The path to the framebuffer device..
* @param width Output parameter for the width of the image.
* @param height Output parameter for the height of the image.
* @return Zero on success, -1 on error.
*/
int
measure (int fbno, char *fbpath, long *width, long *height)
{
static char buf[PATH_MAX];
char *delim;
int sizefd = -1;
ssize_t got;
int saved_errno;
/* Open the file with the framebuffer's dimensions. */
sprintf (buf, "%s/class/graphics/fb%i/virtual_size", SYSDIR, fbno);
sizefd = open (buf, O_RDONLY);
if (sizefd == -1)
FILE_FAILURE (buf);
/* Get the dimensions of the framebuffer. */
got = read (sizefd, buf, sizeof (buf) / sizeof (char) - 1);
if (got < 0)
goto fail;
close (sizefd);
/* The read content is formated as `%{width},%{height}\n`,
convert it to `%{width}\0%{height}\0` and parse it. */
buf[got] = '\0';
delim = strchr (buf, ',');
*delim++ = '\0';
*width = atol (buf);
*height = atol (delim);
return 0;
fail:
saved_errno = errno;
if (sizefd >= 0)
close (sizefd);
errno = saved_errno;
return -1;
(void) fbpath;
}
/**
* Convert read data from a framebuffer to PNM pixel data.
*
* @param file The output image file.
* @param buf Buffer with read data.
* @param n The number of read characters.
* @param adjustment Set to zero if all bytes were converted
* (a whole number of pixels where available,)
* otherwise, set to the number of bytes a
* pixel is encoded.
* @return Zero on success, -1 on error.
*/
int
convert_fb (FILE *file, char *buf, size_t n, size_t *adjustment)
{
uint32_t *pixel;
int r, g, b;
size_t off;
for (off = 0; off < n; off += 4)
{
/* A pixel in the framebuffer is formatted as `%{blue}%{green}%{red}%{x}`
in big-endian binary, or `%{x}%{red}%{green}%{blue}` in little-endian binary. */
pixel = (uint32_t *)(buf + off);
r = (*pixel >> 16) & 255;
g = (*pixel >> 8) & 255;
b = (*pixel >> 0) & 255;
if (SAVE_PIXEL(file, r, g, b) < 0)
goto fail;
}
*adjustment = (off != n ? 4 : 0);
return 0;
fail:
return -1;
}
|
