fromQuaternion method

Matrix3 fromQuaternion(
  1. Quaternion q
)

Creates a rotation matrix from the given quaternion.

Implementation

Matrix3 fromQuaternion(Quaternion q ) {
	final e = elements;

	final x = q.x, y = q.y, z = q.z, w = q.w;
	final x2 = x + x, y2 = y + y, z2 = z + z;
	final xx = x * x2, xy = x * y2, xz = x * z2;
	final yy = y * y2, yz = y * z2, zz = z * z2;
	final wx = w * x2, wy = w * y2, wz = w * z2;

	e[ 0 ] = 1 - ( yy + zz );
	e[ 3 ] = xy - wz;
	e[ 6 ] = xz + wy;

	e[ 1 ] = xy + wz;
	e[ 4 ] = 1 - ( xx + zz );
	e[ 7 ] = yz - wx;

	e[ 2 ] = xz - wy;
	e[ 5 ] = yz + wx;
	e[ 8 ] = 1 - ( xx + yy );

	return this;
}