/**
* Determines the orientation of a LineSegment relative to this segment. The concept of
* orientation is specified as follows: Given two line segments A and L,
*
* <ul
* <li>
* A is to the left of a segment L if A lies wholly in the closed half-plane lying to the left
* of L
* <li>A is to the right of a segment L if A lies wholly in the closed half-plane lying to the
* right of L
* <li>otherwise, A has indeterminate orientation relative to L. This happens if A is collinear
* with L or if A crosses the line determined by L.
* </ul>
*
* @param seg the LineSegment to compare
* @return 1 if <code>seg</code> is to the left of this segment
* @return -1 if <code>seg</code> is to the right of this segment
* @return 0 if <code>seg</code> is collinear to or crosses this segment
*/
public int orientationIndex(LineSegment seg) {
int orient0 = CGAlgorithms.orientationIndex(p0, p1, seg.p0);
int orient1 = CGAlgorithms.orientationIndex(p0, p1, seg.p1);
// this handles the case where the points are L or collinear
if (orient0 >= 0 && orient1 >= 0) return Math.max(orient0, orient1);
// this handles the case where the points are R or collinear
if (orient0 <= 0 && orient1 <= 0) return Math.max(orient0, orient1);
// points lie on opposite sides ==> indeterminate orientation
return 0;
}
/**
* Determines the orientation index of a {@link Coordinate} relative to this segment. The
* orientation index is as defined in {@link CGAlgorithms#computeOrientation}.
*
* @param p the coordinate to compare
* @return 1 (LEFT) if <code>p</code> is to the left of this segment
* @return -1 (RIGHT) if <code>p</code> is to the right of this segment
* @return 0 (COLLINEAR) if <code>p</code> is collinear with this segment
* @see CGAlgorithms#computeOrientation(Coordinate, Coordinate, Coordinate)
*/
public int orientationIndex(Coordinate p) {
return CGAlgorithms.orientationIndex(p0, p1, p);
}
