/**
* 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 "pnm.h"
#include "kern.h"
#define LIST_0_9(P) P"0\n", P"1\n", P"2\n", P"3\n", P"4\n", P"5\n", P"6\n", P"7\n", P"8\n", P"9\n"
/**
* [0, 255]-integer-to-text convertion lookup table for faster conversion from
* raw framebuffer data to the PNM format. The values have a whitespace at the
* end for even faster conversion.
* Lines should not be longer than 70 (although most programs will probably
* work even if there are longer lines), therefore the selected whitespace
* is LF (new line).
*
* ASCII has wider support than binary, and is create for version control,
* especifially with one datum per line.
*/
const char* inttable[] =
{
LIST_0_9(""), LIST_0_9("1"), LIST_0_9("2"), LIST_0_9("3"), LIST_0_9("4"),
LIST_0_9("5"), LIST_0_9("6"), LIST_0_9("7"), LIST_0_9("8"), LIST_0_9("9"),
LIST_0_9("10"), LIST_0_9("11"), LIST_0_9("12"), LIST_0_9("13"), LIST_0_9("14"),
LIST_0_9("15"), LIST_0_9("16"), LIST_0_9("17"), LIST_0_9("18"), LIST_0_9("19"),
LIST_0_9("20"), LIST_0_9("21"), LIST_0_9("22"), LIST_0_9("23"), LIST_0_9("24"),
"250\n", "251\n", "252\n", "253\n", "254\n", "255\n"
};
/**
* Create an PNM file.
*
* @param fbfd The file descriptor connected to framebuffer device.
* @param width The width of the image.
* @param height The height of the image.
* @param imgfd The file descriptor connected to conversion process's stdin.
* @param data Additional data for `convert_fb_to_pnm`
* and `convert_fb_to_png`.
* @return Zero on success, -1 on error.
*/
int
save_pnm (int fbfd, long width, long height, int imgfd, void *restrict data)
{
char buf[8 << 10];
FILE *file = NULL;
ssize_t got, off;
size_t adjustment;
int saved_errno;
/* Create a FILE *, for writing, for the image file. */
file = fdopen (imgfd, "w");
if (file == NULL)
goto fail;
/* The PNM image should begin with `P3\n%{width} %{height}\n%{colour max=255}\n`.
('\n' and ' ' can be exchanged at will.) */
if (fprintf (file, "P3\n%li %li\n255\n", width, height) < 0)
goto fail;
/* Convert raw framebuffer data into a PNM image. */
for (off = 0;;)
{
/* Read data from the framebuffer, we may have up to 3 bytes buffered. */
got = read (fbfd, buf + off, sizeof (buf) - (size_t)off * sizeof (char));
if (got < 0)
goto fail;
if (got == 0)
break;
got += off;
/* Convert read pixels. */
if (convert_fb_to_pnm (file, buf, (size_t)got, &adjustment, data) < 0)
goto fail;
/* If we read a whole number of pixels, reset the buffer, otherwise,
move the unconverted bytes to the beginning of the buffer. */
if (adjustment)
{
off -= (ssize_t)adjustment;
memcpy (buf, buf + off, (size_t)(got - off) * sizeof (char));
off = got - off;
}
else
off = 0;
}
/* Close file and return successfully. */
fflush (file);
fclose (file);
return 0;
fail:
saved_errno = errno;
if (file != NULL)
fclose (file);
errno = saved_errno;
return -1;
}
