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/***************************************************************************
time.c Copyright (C) 2003 Christoph Reichenbach
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public Licence as
published by the Free Software Foundaton; either version 2 of the
Licence, or (at your option) any later version.
It is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
merchantibility or fitness for a particular purpose. See the
GNU General Public Licence for more details.
You should have received a copy of the GNU General Public Licence
along with this program; see the file COPYING. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
Please contact the maintainer for any program-related bug reports or
inquiries.
Current Maintainer:
Christoph Reichenbach (CR) <jameson@linuxgames.com>
***************************************************************************/
#include "sci/include/sfx_time.h"
#include "sci/include/resource.h"
sfx_timestamp_t
sfx_new_timestamp(long secs, long usecs, int frame_rate) {
sfx_timestamp_t r;
r.secs = secs;
r.usecs = usecs;
r.frame_rate = frame_rate;
r.frame_offset = 0;
return r;
}
sfx_timestamp_t
sfx_timestamp_add(sfx_timestamp_t timestamp, int frames) {
timestamp.frame_offset += frames;
if (timestamp.frame_offset < 0) {
int secsub = 1 + (-timestamp.frame_offset / timestamp.frame_rate);
timestamp.frame_offset += timestamp.frame_rate * secsub;
timestamp.secs -= secsub;
}
timestamp.secs += (timestamp.frame_offset / timestamp.frame_rate);
timestamp.frame_offset %= timestamp.frame_rate;
return timestamp;
}
int
sfx_timestamp_frame_diff(sfx_timestamp_t a, sfx_timestamp_t b) {
long usecdelta = 0;
if (a.frame_rate != b.frame_rate) {
fprintf(stderr, "Fatal: The semantics of subtracting two timestamps with a different base from each other is not defined!\n");
BREAKPOINT();
}
if (a.usecs != b.usecs) {
#if (SIZEOF_LONG >= 8)
usecdelta = (a.usecs * a.frame_rate) / 1000000
- (b.usecs * b.frame_rate) / 1000000;
#else
usecdelta = ((a.usecs / 1000) * a.frame_rate) / 1000
- ((b.usecs / 1000) * b.frame_rate) / 1000;
#endif
}
return usecdelta
+ (a.secs - b.secs) * a.frame_rate
+ a.frame_offset - b.frame_offset;
}
long
sfx_timestamp_usecs_diff(sfx_timestamp_t t1, sfx_timestamp_t t2) {
long secs1, secs2;
long usecs1, usecs2;
sfx_timestamp_gettime(&t1, &secs1, &usecs1);
sfx_timestamp_gettime(&t2, &secs2, &usecs2);
return (usecs1 - usecs2) + ((secs1 - secs2) * 1000000);
}
sfx_timestamp_t
sfx_timestamp_renormalise(sfx_timestamp_t timestamp, int new_freq) {
sfx_timestamp_t r;
sfx_timestamp_gettime(×tamp, &r.secs, &r.usecs);
r.frame_rate = new_freq;
r.frame_offset = 0;
return r;
}
void
sfx_timestamp_gettime(sfx_timestamp_t *timestamp, long *secs, long *usecs) {
long ust = timestamp->usecs;
/* On 64 bit machines, we can do an accurate computation */
#if (SIZEOF_LONG >= 8)
ust += (timestamp->frame_offset * 1000000l) / (timestamp->frame_rate);
#else
ust += (timestamp->frame_offset * 1000l) / (timestamp->frame_rate / 1000l);
#endif
if (ust > 1000000) {
ust -= 1000000;
*secs = timestamp->secs + 1;
} else
*secs = timestamp->secs;
*usecs = ust;
}
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