Fix point distance calculation

This fixes the point distance calculation of ALL::Points.

See #60 (closed) for more info.

include/ALL_Point.hpp

@@ -220,31 +220,17 @@ public:
       throw PointDimensionMissmatchException(__FILE__, __func__, __LINE__);
 
     // vectors spanning the plane from vertex 'a'
-    T vb[3];
-    T vc[3];
-
-    for (int i = 0; i < 3; ++i) {
-      vb[i] = B[i] - A[i];
-      vc[i] = C[i] - A[i];
-    }
+    Point<T> vb = B - A;
+    Point<T> vc = C - A;
 
     // normal vector of plane
-    T n[3];
-
-    n[0] = vb[1] * vc[2] - vb[2] * vc[1];
-    n[1] = vb[2] * vc[0] - vb[0] * vc[2];
-    n[2] = vb[0] * vc[1] - vb[1] * vc[0];
-
-    // length of normal vector
-    T dn = n.norm();
+    Point<T> n = vb.cross(vc);
+    n = n/n.norm();
 
-    // distance from origin
-    T d = n * A;
-
-    // compute distance of test vertex to plane
-    return std::abs((n[0] * coordinates.at(0) + n[1] * coordinates.at(1) +
-                     n[2] * coordinates.at(2) - d) /
-                    dn);
+    // return r.n - A.n = (r-A).n as distance from plane to r
+    return std::abs( (coordinates.at(0) - A[0]) * n[0] +
+		     (coordinates.at(1) - A[1]) * n[1] +
+		     (coordinates.at(2) - A[2]) * n[2] );
   }
 
   /// operator for the addition of two point objects
@@ -301,6 +287,17 @@ public:
     return result;
   }
 
+  /// operator to scale the local point object by a provided factor
+  /// @param rhs scaling factor
+  /// @return scaled point object
+  Point<T> operator/(const T &rhs) const {
+    Point<T> result(dimension);
+    for (int d = 0; d < dimension; ++d) {
+      result[d] = coordinates.at(d) / rhs;
+    }
+    return result;
+  }
+
   /// operator to compute the cross product between two point objects
   /// @param rhs point object to compute the cross product with
   /// @return cross product between the two point objects