Import the SCI engine sources from the FreeSCI Glutton branch (it doesn't compile yet)

svn-id: r38192

1 files changed, 131 insertions, 0 deletions

diff --git a/engines/sci/sfx/time.c b/engines/sci/sfx/time.c
new file mode 100644
index 0000000000..553eb406f8
--- /dev/null
+++ b/engines/sci/sfx/time.c
@@ -0,0 +1,131 @@
+/***************************************************************************
+ 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 <sfx_time.h>
+#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(&timestamp, &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;
+}
+