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