frustum.h

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/*
 * frustum.h
 *
 * Copyright (C) 2009,2010  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 frustum object (mostly used for 3D rendering).
 */

#ifndef WAVEPACKET_FRUSTUM_H__
#define WAVEPACKET_FRUSTUM_H__

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


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


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


/// Basic frustum object.  This is a truncated 4-sided pyramid, also called a
///   right square frustum.  See http://en.wikipedia.org/wiki/Frustum
struct frustum_t {
        // public enums --------------------------------------------------------

        /// this enum defines planes as if someone was standing at the apex of
        ///  the frustum, and looking down it.
        enum ePlane {
                eTop            = 0,    ///< index of top plane
                eBottom         = 1,    ///< index of bottom plane
                eLeft           = 2,    ///< index of left plane
                eRight          = 3,    ///< index of right plane
                eNear           = 4,    ///< index of near plane
                eFar            = 5,    ///< index of far plane

                // keep these last!
                eEdgeCount      = 12,   ///< total number of edges
                ePlaneCount     = 6     ///< total number of planes
        };

        // constructor, destructor ---------------------------------------------
        frustum_t(void) throw() {}

        // manipulators --------------------------------------------------------
        void clear(void) throw() {
                        for (int i = 0; i < ePlaneCount; ++i) {
                                plane[i].clear();
                        }
                }

        void dump(IN const char * msg) const throw() {
                        DPRINTF("%s (frustum):", msg);
                        plane[eTop].dump(   "    top   :");
                        plane[eBottom].dump("    bottom:");
                        plane[eLeft].dump(  "    left  :");
                        plane[eRight].dump( "    right :");
                        plane[eFar].dump(   "    far   :");
                        plane[eNear].dump(  "    near  :");
                }

        /// does the frustum contain the given rectangle?
        eContains containsRect(IN const rect3d_t& r) const throw();

        /// does the frustum contain the given sphere?
        eContains containsSphere(IN const point3d_t& position,
                                IN float radius) const throw();

        /// returns the endpoints of the specified edge
        ///     (0 <= index < eEdgeCount)
        void getEdge(IN int index,
                                OUT point3d_t& p0,
                                OUT point3d_t& p1) const throw();

        // data fields ---------------------------------------------------------
        plane_t         plane[ePlaneCount];  // a frustum is defined by 6 planes
};



/// create a view frustum given basic geometric information.
/// Keep in mind, this uses standard OpenGL right-handed coordinates, with Y
///   being the usual up direction, and x and z in the plane of the ground.
bool createViewFrustum(IN const point3d_t& position,
                                IN const point3d_t& facing,
                                IN const point3d_t& up,
                                IN float fovyRadians,   ///< field of view, Y
                                IN float zNear,
                                IN float zFar,
                                IN float aspect,
                                OUT frustum_t& frustum) throw();



#endif  // WAVEPACKET_FRUSTUM_H__