src/main/java/de/javagl/geom/Lines.java
/**
     * Computes the angle, in radians, between the given lines, as a value
     * between 0 and 2PI.
     * 
     * @param sx0 The x-coordinate of the start point of the first line 
     * @param sy0 The y-coordinate of the start point of the first line
     * @param ex0 The x-coordinate of the end point of the first line
     * @param ey0 The y-coordinate of the end point of the first line
     * @param sx1 The x-coordinate of the start point of the second line
     * @param sy1 The y-coordinate of the start point of the second line
     * @param ex1 The x-coordinate of the end point of the second line
     * @param ey1 The y-coordinate of the end point of the second line
     * @return The angle, in radians, between the given lines
     */
Computes the angle, in radians, between the given lines, as a value
between 0 and 2PI.


Computes the angle in radians between the given lines as a value between 0 and 2PI .
public static double angle(
        double sx0, double sy0, double ex0, double ey0,
        double sx1, double sy1, double ex1, double ey1)
    {
        return normalizeAngle(
            angleToX(sx1, sy1, ex1, ey1) - 
            angleToX(sx0, sy0, ex0, ey0));
    }
public static double angle ( double sx0 , double sy0 , double ex0 , double ey0 , double sx1 , double sy1 , double ex1 , double ey1 ) { return normalizeAngle ( angleToX ( sx1 , sy1 , ex1 , ey1 ) - angleToX ( sx0 , sy0 , ex0 , ey0 ) ) ; }
Computes the angle, in radians, between the given lines, as a value
 between 0 and 2PI.
Computes the angle in radians between the given lines as a value between 0 and 2PI .