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extern struct win *fore;
/*
* BRLTTY - Access software for Unix for a blind person
* using a soft Braille terminal
*
* Version 0.22 BETA, 22 September 1995
*
* Copyright (C) 1995 by Nikhil Nair & James Bowden. All rights reserved.
* BRLTTY comes with ABSOLUTELY NO WARRANTY.
*
* This is free software, placed under the terms of the
* GNU General Public License, as published by the Free Software
* Foundation. Please see the file COPYING for details.
*
* This software is maintained by Nikhil Nair <nn201@cam.ac.uk>.
*/
/* scr.c - The screen reading library
* N. Nair, 21 July 1995
*/
#define SCR_C 1
#define TOGGLE_OFF 5000
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <syslog.h>
#include <errno.h>
#include "scr.h"
#if defined (__XABT) || defined (__XSCREADER)
char VCS_FILE[50];
#endif
scrstat scr;
int scr_fd;
int my_initscr ()
{
scr_fd = open (VCS_FILE, O_RDONLY); /* open vcsa device for read-only */
if (scr_fd == -1)
return 1;
return 0;
}
scrstat getstat ()
{
unsigned char buffer[4];
static scrstat stat;
lseek (scr_fd, 0, SEEK_SET); /* go to start of file */
read (scr_fd, buffer, 4); /* get screen status bytes */
stat.rows = buffer[0];
stat.cols = buffer[1];
stat.posx = buffer[2];
stat.posy = buffer[3];
return stat;
}
char *getscr (int left, int top, int width, int height, char *buffer, int mode)
{
scrstat stat; /* screen statistics */
off_t start; /* start offset */
size_t linelen; /* number of bytes to read for one */
/* complete line */
char linebuf[512]; /* line buffer; larger than is needed */
int i, j; /* loop counters */
stat = getstat ();
if (left < 0 || top < 0 || width < 1 || height < 1 \
|| mode < 0 || mode > 1 || left + width > stat.cols \
|| top + height > stat.rows)
return NULL;
#ifdef __XABT
# define X 1
#else
# define X 2
#endif
start = 4 + (top * stat.cols + left) * X + mode;
linelen = X * width - 1;
for (i = 0; i < height; i++)
{
lseek (scr_fd, start + i * stat.cols * X, SEEK_SET);
read (scr_fd, linebuf, linelen);
for (j = 1; j < width; linebuf[j++] = linebuf[j * X]);
memcpy (buffer + i * width, linebuf, width);
}
return buffer;
}
/****************************************************************\
* getscrinfo - Gets info on size of screen and cursor possition. *
\****************************************************************/
void getscrinfo ()
{
if (my_initscr ())
{
#if defined __JABT || defined __XABT
play_sample ("screen_error.au", TOGGLE_OFF);
wait (NULL);
#endif
syslog (LOG_USER | LOG_ERR, "%s: Can't initialise screen reading: %s", VCS_FILE, strerror (errno));
exit (1);
} /* if */
scr = getstat (); /* get rows, cols, cursorpos */
} /* getscrinfo */
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