raytrace.cpp

/** 
 * @file raytrace.cpp
 * @brief Functions called by box object scripts.
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "linden_common.h"

#include "math.h"
//#include "vmath.h"
#include "v3math.h"
#include "llquaternion.h"
#include "m3math.h"
#include "raytrace.h"


BOOL line_plane(const LLVector3 &line_point, const LLVector3 &line_direction,
				const LLVector3 &plane_point, const LLVector3 plane_normal, 
				LLVector3 &intersection)
{
	F32 N = line_direction * plane_normal;
	if (0.0f == N)
	{
		// line is perpendicular to plane normal
		// so it is either entirely on plane, or not on plane at all
		return FALSE;
	}
	// Ax + By, + Cz + D = 0
	// D = - (plane_point * plane_normal)
	// N = line_direction * plane_normal
	// intersection = line_point - ((D + plane_normal * line_point) / N) * line_direction
	intersection = line_point - ((plane_normal * line_point - plane_point * plane_normal) / N) * line_direction;
	return TRUE;
}


BOOL ray_plane(const LLVector3 &ray_point, const LLVector3 &ray_direction,
			   const LLVector3 &plane_point, const LLVector3 plane_normal, 
			   LLVector3 &intersection)
{
	F32 N = ray_direction * plane_normal;
	if (0.0f == N)
	{
		// ray is perpendicular to plane normal
		// so it is either entirely on plane, or not on plane at all
		return FALSE;
	}
	// Ax + By, + Cz + D = 0
	// D = - (plane_point * plane_normal)
	// N = ray_direction * plane_normal