/*
===========================================================================
Copyright (C) 1999 - 2005, Id Software, Inc.
Copyright (C) 2000 - 2013, Raven Software, Inc.
Copyright (C) 2001 - 2013, Activision, Inc.
Copyright (C) 2013 - 2015, OpenJK contributors

This file is part of the OpenJK source code.

OpenJK is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
===========================================================================
*/

// tr_mesh.c: triangle model functions

#include "tr_local.h"


float ProjectRadius( float r, vec3_t location )
{
	float pr;
	float dist;
	float c;
	vec3_t	p;
	float width;
	float depth;

	c = DotProduct( tr.viewParms.ori.axis[0], tr.viewParms.ori.origin );
	dist = DotProduct( tr.viewParms.ori.axis[0], location ) - c;

	if ( dist <= 0 )
		return 0;

	p[0] = 0;
	p[1] = Q_fabs( r );
	p[2] = -dist;

	width = p[0] * tr.viewParms.projectionMatrix[1] +
		           p[1] * tr.viewParms.projectionMatrix[5] +
				   p[2] * tr.viewParms.projectionMatrix[9] +
				   tr.viewParms.projectionMatrix[13];

	depth = p[0] * tr.viewParms.projectionMatrix[3] +
		           p[1] * tr.viewParms.projectionMatrix[7] +
				   p[2] * tr.viewParms.projectionMatrix[11] +
				   tr.viewParms.projectionMatrix[15];

	pr = width / depth;

	if ( pr > 1.0f )
		pr = 1.0f;

	return pr;
}