touchpad: make tp_estimate_delta return fractions

Force a cast of the input arguments to a double before the divide, rather
than after the divide.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
index 4d4856f..b0520c7 100644 (file)
--- a/src/evdev-mt-touchpad.c
+++ b/src/evdev-mt-touchpad.c
@@ -163,7 +163,7 @@ tp_end_touch(struct tp_dispatch *tp, struct tp_touch *t, uint64_t time)
 static double
 tp_estimate_delta(int x0, int x1, int x2, int x3)
 {
-       return (x0 + x1 - x2 - x3) / 4;
+       return (x0 + x1 - x2 - x3) / 4.0;
 }
 
 void