MTQuaternion

This class represents a quaternion defined by the four parameters x, y, z and w.

Methods:

* getter
-(double)x -(double)y -(double)z -(double)w	returns the coordinates
-(MTMatrix44*)rotationMatrix	returns the rotation matrix (4.3)
* operations
-(MTQuaternion*)invert
-(id)normalize	$sqrt(x^{2}+y^{2}+z^{2}+w^{2})=1$
-(id)rotate: (double)phi	rotates this quaternion by the given angle phi
-(id)multiplyWith: (MTQuaternion*)q2	combines two quaternions
* creation
+(MTQuaternion*)rotation: (double)phi aroundAxis:(MTCoordinates*)ax	creates a new quaternion which represents the rotation around an axis (3.9)
+(MTQuaternion*)identity	creates a new quaternion with coordinates: (0,0,0) and w=1.0.