src/main/java/de/javagl/geom/Lines.java
/**
     * Computes the angle, in radians, that the line from p0 to p1
     * has to the x axis
     * 
     * @param p0 The start point of the line
     * @param p1 The end point of the line
     * @return The angle, in radians, that the line has to the x-axis
     */
Computes the angle, in radians, that the line from p0 to p1
has to the x axis

@param p0 The start point of the line
@param p1 The end point of the line
@return The angle, in radians, that the line has to the x-axis
Computes the angle in radians that the line from p0 to p1 has to the x axis @param p0 The start point of the line @param p1 The end point of the line @return The angle in radians that the line has to the x - axis
public static double angleToX(
        Point2D p0, Point2D p1)
    {
        return angleToX(
            p0.getX(), p0.getY(), 
            p1.getX(), p1.getY());
    }
public static double angleToX ( Point2D p0 , Point2D p1 ) { return angleToX ( p0 . getX ( ) , p0 . getY ( ) , p1 . getX ( ) , p1 . getY ( ) ) ; }
Computes the angle, in radians, that the line from p0 to p1
 has to the x axis
Computes the angle in radians that the line from p0 to p1 has to the x axis