/*
* 2ooM: The Master of Orion II Reverse Engineering Project
* Miscellaneous common routines for liblbx.
* Copyright (C) 2006-2008 Nick Bowler
*
* 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 .
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include
#include
#include "misc.h"
#include "lbx.h"
int _lbx_fseek(FILE *f, long *current, size_t offset)
{
static unsigned char oblivion[1024];
long dist;
if (*current < offset) {
dist = offset - *current;
} else if (*current > offset) {
dist = -(long)(*current - offset);
} else {
return 0;
}
if (fseek(f, dist, SEEK_CUR) == 0) {
*current += dist;
} else if (*current < offset) {
while (dist) {
size_t rc, amt = MIN(sizeof oblivion, dist);
rc = fread(oblivion, 1, amt, f);
*current += rc;
dist -= rc;
if (rc < amt) {
if (feof(f))
lbx_errno = LBX_EEOF;
else
lbx_errno = -errno;
return -1;
}
}
} else {
lbx_errno = -errno;
return -1;
}
return 0;
}