Fix isccw to return correct ccw answer.

git-svn-id: http://svn.osgeo.org/postgis/trunk@2317 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/lwgeom/lwgeom_api.c b/lwgeom/lwgeom_api.c
index f11d36ba497572a74d0e85aeb400dbbe1ea31128..70468652bfaa04eed57a27189120e6247bfcb46e 100644 (file)
--- a/lwgeom/lwgeom_api.c
+++ b/lwgeom/lwgeom_api.c
@@ -1867,7 +1867,7 @@ ptarray_isccw(const POINTARRAY *pa)
        {
                getPoint2d_p(pa, i, &p1);
                getPoint2d_p(pa, i+1, &p2);
-               area += (p1.x * p2.y) - (p1.y * p2.x);
+               area += (p1.y * p2.x) - (p1.x * p2.y);
        }
        if ( area > 0 ) return 0;
        else return 1;