# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1365827252 -10800
# Node ID fb9659ca5cf247446475c8dd7ded5fb73cc8058b
# Parent  9915b036863d8ef7257c8c3f090529a4a4158406
added ping-pong extrapolator

diff -r 9915b036863d -r fb9659ca5cf2 src/track.c
--- a/src/track.c	Sun Mar 10 18:52:57 2013 +0200
+++ b/src/track.c	Sat Apr 13 07:27:32 2013 +0300
@@ -14,6 +14,7 @@
 static anm_time_t remap_extend(anm_time_t tm, anm_time_t start, anm_time_t end);
 static anm_time_t remap_clamp(anm_time_t tm, anm_time_t start, anm_time_t end);
 static anm_time_t remap_repeat(anm_time_t tm, anm_time_t start, anm_time_t end);
+static anm_time_t remap_pingpong(anm_time_t tm, anm_time_t start, anm_time_t end);
 
 /* XXX keep this in sync with enum anm_interpolator at track.h */
 static float (*interp[])(float, float, float, float, float) = {
@@ -28,6 +29,7 @@
 	remap_extend,
 	remap_clamp,
 	remap_repeat,
+	remap_pingpong,
 	0
 };
 
@@ -304,3 +306,11 @@
 	}
 	return (tm - start) % interv + start;*/
 }
+
+static anm_time_t remap_pingpong(anm_time_t tm, anm_time_t start, anm_time_t end)
+{
+	anm_time_t interv = end - start;
+	anm_time_t x = remap_repeat(tm, start, end + interv);
+
+	return x > end ? end + interv - x : x;
+}
diff -r 9915b036863d -r fb9659ca5cf2 src/track.h
--- a/src/track.h	Sun Mar 10 18:52:57 2013 +0200
+++ b/src/track.h	Sat Apr 13 07:27:32 2013 +0300
@@ -16,7 +16,8 @@
 enum anm_extrapolator {
 	ANM_EXTRAP_EXTEND,	/* extend to infinity */
 	ANM_EXTRAP_CLAMP,	/* clamp to last value */
-	ANM_EXTRAP_REPEAT	/* repeat motion */
+	ANM_EXTRAP_REPEAT,	/* repeat motion */
+	ANM_EXTRAP_PINGPONG	/* repeat with mirroring */
 };
 
 typedef long anm_time_t;