Fix indexing for negatives

diff --git a/incl/rrtbase.h b/incl/rrtbase.h
index 98b4ceec731989210cb50b05a457fa2ef0e96e4e..5c46747fb8ae6f4214ef652c1b1bfa3df78d01ee 100644 (file)
--- a/incl/rrtbase.h
+++ b/incl/rrtbase.h
@@ -33,11 +33,11 @@ along with I am car. If not, see <http://www.gnu.org/licenses/>.
 #define IXSIZE 100
 #define IXSTEP (1.0 * ((VMAX) - (VMIN)) / IXSIZE)
 #define IXI(x) ({ __typeof__ (x) _x = (x); \
-                (int) floor(_x / IXSTEP); })
+                std::abs((int) floor(_x / IXSTEP)); })
 #define IYSIZE 100
 #define IYSTEP (1.0 * ((HMAX) - (HMIN)) / IYSIZE)
 #define IYI(y) ({ __typeof__ (y) _y = (y); \
-                (int) floor(_y / IYSTEP); })
+                std::abs((int) floor(_y / IYSTEP)); })
 
 class Cell {
         private: