plane.h

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/*
 * plane.h
 *
 * Copyright (C) 2009  Thomas A. Vaughan
 * All rights reserved.
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THOMAS A. VAUGHAN ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THOMAS A. VAUGHAN BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * Basic 2D plane as represented in 3D space.
 */

#ifndef WAVEPACKET_PLANE_H__
#define WAVEPACKET_PLANE_H__

// includes --------------------------------------------------------------------
#include "geometry_3d.h"


/// \ingroup geometry
/*@{*/


// common typedefs -------------------------------------------------------------


/// basic 2D plane in 3D space.  This is composed of a normal (vector), and
///   a distance D (along the normal) from the origin.
///
/// Note that a point p in the plane satisfies the equation n.p = d.
///
/// Likewise, the distance from any point p to the plane is n.p - d (= 0 for
///     points p in the plane, obviously).
struct plane_t {
        plane_t(void) throw() { }

        void clear(void) throw() {
                        n.clear();
                        d = 0.0;
                }

        void dump(IN const char * msg) const throw() {
                        DPRINTF("%s (plane): n = (%6.3f, %6.3f, %6.3f)  d = %7.2f",
                            msg, n.x, n.y, n.z, d);
                }

        /// returns distance from point to plane measured along normal
        float distance(IN const point3d_t& p) const throw() {
                        return dotProduct(p, n) - d;
                }

        // data fields ---------------------------------------------------------
        point3d_t       n;      ///< n is the normal vector to the plane
        float           d;      ///< d is the distance to origin along normal
};



/// given two planes (A and B) return the line of intersection between them.
/// Returns false if the planes are parallel (or coincident), in which case
///     there is no single line of intersection.
/// The intersection line is defined as p(t) = p0 + t pt.
bool getLineOfIntersection(IN const plane_t& A, IN const plane_t& B,
                                OUT point3d_t& p0, OUT point3d_t& pt) throw();


#endif  // WAVEPACKET_PLANE_H__