From 4a9be13d2aed3fc90230cff34fff57fa70cf574c Mon Sep 17 00:00:00 2001
From: =?utf8?q?Kristian=20H=C3=B8gsberg?= <krh@bitplanet.net>
Date: Mon, 2 May 2011 13:38:03 -0400
Subject: [PATCH] Tweak tweener constants and add friction parameter

---
 compositor/compositor.c         | 13 ++++++++++---
 compositor/compositor.h         |  1 +
 compositor/meego-tablet-shell.c |  2 +-
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/compositor/compositor.c b/compositor/compositor.c
index 6288337..5df67d1 100644
--- a/compositor/compositor.c
+++ b/compositor/compositor.c
@@ -116,6 +116,7 @@ wlsc_tweener_init(struct wlsc_tweener *tweener,
 		  double k, double current, double target)
 {
 	tweener->k = k;
+	tweener->friction = 100.0;
 	tweener->current = current;
 	tweener->previous = current;
 	tweener->target = target;
@@ -124,22 +125,28 @@ wlsc_tweener_init(struct wlsc_tweener *tweener,
 WL_EXPORT void
 wlsc_tweener_update(struct wlsc_tweener *tweener, uint32_t msec)
 {
-	double force, current, step;
+	double force, v, current, step;
 
-	step = (msec - tweener->timestamp) / 100.0;
+	step = (msec - tweener->timestamp) / 500.0;
 	tweener->timestamp = msec;
 
 	current = tweener->current;
+	v = current - tweener->previous;
 	force = tweener->k * (tweener->target - current) / 10.0 +
-		(tweener->previous - current);
+		(tweener->previous - current) - v * tweener->friction;
 
 	tweener->current =
 		current + (current - tweener->previous) + force * step * step;
 	tweener->previous = current;
 
 	if (tweener->current >= 1.0) {
+#ifdef TWEENER_BOUNCE
+		tweener->current = 2.0 - tweener->current;
+		tweener->previous = 2.0 - tweener->previous;
+#else
 		tweener->current = 1.0;
 		tweener->previous = 1.0;
+#endif
 	}
 
 	if (tweener->current <= 0.0) {
diff --git a/compositor/compositor.h b/compositor/compositor.h
index 2db98a1..48e2ebe 100644
--- a/compositor/compositor.h
+++ b/compositor/compositor.h
@@ -106,6 +106,7 @@ struct wlsc_animation {
 
 struct wlsc_tweener {
 	double k;
+	double friction;
 	double current;
 	double target;
 	double previous;
diff --git a/compositor/meego-tablet-shell.c b/compositor/meego-tablet-shell.c
index 44480b2..6dbb0b9 100644
--- a/compositor/meego-tablet-shell.c
+++ b/compositor/meego-tablet-shell.c
@@ -525,6 +525,6 @@ shell_init(struct wlsc_compositor *compositor)
 
 	launch_switcher(shell);
 
-	wlsc_tweener_init(&compositor->fade.tweener, 0.8, 1.0, 1.0);
+	wlsc_tweener_init(&compositor->fade.tweener, 40.0, 1.0, 1.0);
 	shell->starting = 1;
 }
-- 
2.7.4