X-Git-Url: http://shamusworld.gotdns.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fvector.cpp;h=ac5a2058191e4f7e11d24218ba8085e93d7372d8;hb=4b37ccbdf263a4798e53a62e33d869a728ace283;hp=ab1433f9c6a5123e6ca6a8475cbe852210ecb933;hpb=11802354d1ddc5bc571d83d8fc9b600618cb4372;p=architektonas

diff --git a/src/vector.cpp b/src/vector.cpp
index ab1433f..ac5a205 100644
--- a/src/vector.cpp
+++ b/src/vector.cpp
@@ -244,11 +244,19 @@ double Vector::Parameter(Vector v1, Vector v2, Vector p)
 	// the perpendicular lies beyond the 1st endpoint. If pp > 1, then the
 	// perpendicular lies beyond the 2nd endpoint.
 
-	Vector lineSegment = v2 - v1;
+	Vector lineSegment = v1 - v2;
 	double magnitude = lineSegment.Magnitude();
-	Vector pointSegment = p - v1;
+	Vector pointSegment = p - v2;
 	double t = lineSegment.Dot(pointSegment) / (magnitude * magnitude);
-
 	return t;
 }
 
+
+// Return the normal to the linesegment formed by the passed in points.
+// (Not sure which is head or tail, or which hand the normal lies)
+/*static*/ Vector Vector::Normal(Vector v1, Vector v2)
+{
+	Vector v = (v1 - v2).Unit();
+	return Vector(-v.y, v.x);
+}
+