/* -*- C++ -*-
 * Copyright ©2004 Hugo Mills <hugo@carfax.org.uk>
 *
 * This software is distributed under the terms of the GNU GPL v3
 * For more information on the GPL, see the file COPYING or 
 * visit http://www.gnu.org/
 *
 * This software is distributed without warranty
 */

#include "magellan/xfsphere.h"

bool XfSphere::f(dvec3& result, const dvec2& ll) const
{
	double cy = cos(ll[1]);
	result[0] = sin(ll[0])*cy;
	result[1] = sin(ll[1]);
	result[2] = cos(ll[0])*cy;

	return true;
}

bool XfSphere::g(dvec2& result, const dvec3& p) const
{
	// Assume normalised here?
	// Best not to, but it's slower...
	// Assumed normalised for the moment.

	result[0] = atan2(p[0], p[2]); // Doesn't matter about normalisation
	result[1] = asin(p[1]); // Does matter about normalisation

	return true;
}