Function quat_to_axis_angle 

pub fn quat_to_axis_angle(q: [f32; 4]) -> [f32; 4]

Converts a quaternion [w, x, y, z] to axis-angle [ax, ay, az, angle].

The angle is in radians. Identity quaternion [1, 0, 0, 0] produces [0, 0, 0, 0] (zero rotation).