/**
* D-function is used to calculate where a point is located in reference to an edge. If the value
* is larger than 0 the point is on the left. If it is larger than 0 it's to the right. Equal to 0
* then the point coincides with the edge. Dabp = ((Xa-Xb)*(Ya-Yp)-(Ya-Yb)*(Xa-Xp))
*
* @param edge the edge for calculating the D-function
* @return D-Function value
*/
public double dFunction(Edge edge) {
double dValue =
(edge.getStartPoint().getxCoord() - edge.getEndPoint().getxCoord())
* (edge.getStartPoint().getyCoord() - yCoord)
- (edge.getStartPoint().getyCoord() - edge.getEndPoint().getyCoord())
* (edge.getStartPoint().getxCoord() - xCoord);
return dValue;
}
/**
* Calculates the D-Function to check if the coordinate is placed on the edge or not.
*
* @param edge the edge the point may possibly be on
* @return if the point falls on the edge or not
*/
public boolean dFunctionCheck(Edge edge) {
boolean touching = false;
double dValue =
(edge.getStartPoint().getxCoord() - edge.getEndPoint().getxCoord())
* (edge.getStartPoint().getyCoord() - yCoord)
- (edge.getStartPoint().getyCoord() - edge.getEndPoint().getyCoord())
* (edge.getStartPoint().getxCoord() - xCoord);
if (Math.abs(dValue) <= round) touching = true;
return touching;
}
/**
* Calculates the shortest distance between this coordinate and the given edge
*
* @param edge the edge to get the distance to
* @return the shortest distance between the edge and this coordinate
*/
public double shortestDistanceToEdge(Edge edge) {
double distanceToStartPoint = distanceTo(edge.getStartPoint());
double anglePointEdge = edge.getStartPoint().calculateAngle(this, edge.getEndPoint());
double shortestDistance = distanceToStartPoint * Math.sin(anglePointEdge);
return shortestDistance;
}