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authorNicolas Schodet2012-05-05 19:02:53 +0200
committerNicolas Schodet2012-05-05 19:02:53 +0200
commit0fcdbb1904c2f1c32c80ebe4da367742ef6e00bc (patch)
treec759272b7853cbc0ae4b0941d49ccc7e9291169f /digital/avr/modules/math/geometry/intersection.c
parente50baf1bcea86bd969b7d87e9dd643607ef7f161 (diff)
digital/avr/modules/math/geometry: slightly change intersection meaning
When a segment end is exactly on the other segment, consider there is no intersection.
Diffstat (limited to 'digital/avr/modules/math/geometry/intersection.c')
-rw-r--r--digital/avr/modules/math/geometry/intersection.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/digital/avr/modules/math/geometry/intersection.c b/digital/avr/modules/math/geometry/intersection.c
index 1f8a9278..a1daf72d 100644
--- a/digital/avr/modules/math/geometry/intersection.c
+++ b/digital/avr/modules/math/geometry/intersection.c
@@ -25,18 +25,21 @@
#include "common.h"
#include "intersection.h"
-/** Compare a and b to determine if a / b is in [0:1]. Return non zero if
+/** Compare a and b to determine if a / b is in ]0:1[. Return non zero if
* true. */
static uint8_t
intersection_div_is_in_0_1 (int32_t a, int32_t b)
{
+ assert (b != 0);
/* Test sign, a / b < 0 if different. */
- if ((a >> 31) ^ (b >> 31))
+ if ((a ^ b) & 0x80000000)
+ return 0;
+ else if (a == 0)
return 0;
else if (a > 0)
- return a <= b;
+ return a < b;
else
- return a >= b;
+ return a > b;
}
uint8_t