package java3d;

public class AxisAngle4d {
	public double angle;
	public double x;
	public double y;
	public double z;
	final static double EPS = 1.0e-12;
	
	// コンストラクタ
	public AxisAngle4d() {
		x = 0.0;
		y = 0.0;
		z = 0.0;		
	}

	//　コンストラクタ
	public AxisAngle4d(double px, double py, double pz, double pa) {
		x = px;
		y = py;
		z = pz;
		angle = pa;
	}
	
	public AxisAngle4d(AxisAngle4d a) {
		x = a.x;
		y = a.y;
		z = a.z;
		angle = a.angle;
	}

	public AxisAngle4d(Vector3d axis, double angle) {
		x = axis.x;
		y = axis.y;
		z = axis.z;
		this.angle = angle;
	}
	
	public final void set(Quat4d q1)
    {
        double mag = q1.x*q1.x + q1.y*q1.y + q1.z*q1.z;

        if( mag > EPS ) {
	    mag = Math.sqrt(mag);
	    double invMag = 1.0/mag;

	    x = q1.x*invMag;
	    y = q1.y*invMag;
	    z = q1.z*invMag;
	    angle = 2.0*Math.atan2(mag, q1.w);
	} else {
           x = 0.0d;
           y = 1.0d;
           z = 0.0d;
	   angle = 0.0d;
        }
    }
	
	public AxisAngle4d clone() {
		return new AxisAngle4d(x, y, z, angle);
	}
	
}