244a245,320
> 
> 	/**
> 	 * compute distance of point from line segment, or
> 	 * Double.MAX_VALUE if perpendicular projection is outside segment; or
> 	 * If pts on line are same, return distance from point
> 	 **/
> 	// from Doug Lea's PolygonFigure
> 	public static double distanceFromLine(int xa, int ya,
> 										int xb, int yb,
> 										int xc, int yc) {
> 
> 
> 		// source:http://vision.dai.ed.ac.uk/andrewfg/c-g-a-faq.html#q7
> 		//Let the point be C (XC,YC) and the line be AB (XA,YA) to (XB,YB).
> 		//The length of the
> 		//      line segment AB is L:
> 		//
> 		//                    ___________________
> 		//                   |        2         2
> 		//              L = \| (XB-XA) + (YB-YA)
> 		//and
> 		//
> 		//                  (YA-YC)(YA-YB)-(XA-XC)(XB-XA)
> 		//              r = -----------------------------
> 		//                              L**2
> 		//
> 		//                  (YA-YC)(XB-XA)-(XA-XC)(YB-YA)
> 		//              s = -----------------------------
> 		//                              L**2
> 		//
> 		//      Let I be the point of perpendicular projection of C onto AB, the
> 		//
> 		//              XI=XA+r(XB-XA)
> 		//              YI=YA+r(YB-YA)
> 		//
> 		//      Distance from A to I = r*L
> 		//      Distance from C to I = s*L
> 		//
> 		//      If r < 0 I is on backward extension of AB
> 		//      If r>1 I is on ahead extension of AB
> 		//      If 0<=r<=1 I is on AB
> 		//
> 		//      If s < 0 C is left of AB (you can just check the numerator)
> 		//      If s>0 C is right of AB
> 		//      If s=0 C is on AB
> 
> 		int xdiff = xb - xa;
> 		int ydiff = yb - ya;
> 		long l2 = xdiff * xdiff + ydiff * ydiff;
> 
> 		if (l2 == 0) {
> 			return Geom.length(xa, ya, xc, yc);
> 		}
> 
> 		double rnum =  (ya - yc) * (ya - yb) - (xa - xc) * (xb - xa);
> 		double r = rnum / l2;
> 
> 		if (r < 0.0 || r > 1.0) {
> 			return Double.MAX_VALUE;
> 		}
> 
> 		double xi = xa + r * xdiff;
> 		double yi = ya + r * ydiff;
> 		double xd = xc - xi;
> 		double yd = yc - yi;
> 		return Math.sqrt(xd * xd + yd * yd);
> 
> 		/*
> 			for directional version, instead use
> 			double snum =  (ya-yc) * (xb-xa) - (xa-xc) * (yb-ya);
> 			double s = snum / l2;
> 
> 			double l = Math.sqrt((double)l2);
> 			return = s * l;
> 			*/
> 	}