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authorKeith Packard <keithp@keithp.com>2014-06-05 18:31:06 -0700
committerKeith Packard <keithp@keithp.com>2014-06-05 18:31:06 -0700
commitd7df6e8c47df35c0d27f1a2559ecc305ef28d271 (patch)
treef1fda972e2337087ebedddab27550d27d852758c /src
parent2db2b75f8847ca0066bb19771653a65c9098ae52 (diff)
altos: ao_distance was overflowing when checking for longitude wrap
Need to shift everyone right one bit to fit in 32 bits Signed-off-by: Keith Packard <keithp@keithp.com>
Diffstat (limited to 'src')
-rw-r--r--src/kernel/ao_distance.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/src/kernel/ao_distance.c b/src/kernel/ao_distance.c
index ba7d59fe..5654182a 100644
--- a/src/kernel/ao_distance.c
+++ b/src/kernel/ao_distance.c
@@ -24,6 +24,7 @@ ao_dist(int32_t a, int32_t b)
int32_t d = a - b;
if (d < 0)
d = -d;
+
return (uint32_t) ((int64_t) d * 111198 / 10000000);
}
@@ -98,7 +99,7 @@ ao_lon_dist(int32_t lon_a, int32_t lon_b)
uint32_t lon_dist;
/* check if it's shorter to go the other way around */
- if (lon_a < lon_b - 1800000000)
+ if ((lon_a >> 1) < (lon_b >> 1) - (1800000000 >> 1))
lon_a += 3600000000;
lon_dist = ao_dist(lon_a, lon_b);
if (c) {