Comply with MT syncronization protocol

The latest semantic clarifications in the kernel MT protocol allow
SYN_MT_REPORT to be sent without actually sending any finger data. Add
a mask to the hardware data so that the data actually read can be
tracked.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

1 files changed, 1 insertions, 8 deletions

diff --git a/src/state.c b/src/state.c
index 774828a..31eca70 100644
--- a/src/state.c
+++ b/src/state.c
@@ -36,16 +36,9 @@ static int fincmp(const void *a, const void *b)
         return ((struct FingerState *)a)->id - ((struct FingerState *)b)->id;
 }
 
-/* seander@cs.stanford.edu */
-inline unsigned abs32(int x)
-{
-        int const m = x >> 31;
-        return (x + m) ^ m;
-}
-
 inline int abs15(int x)
 {
-        return 32767 & abs32(x);
+        return 32767 & (x < 0 ? -x : x);
 }
 
 /* abslute scale is assumed to fit in 15 bits */