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00001 
+00007 /* Copyright, 2000, 2001 Nevrax Ltd.
+00008  *
+00009  * This file is part of NEVRAX NEL.
+00010  * NEVRAX NEL is free software; you can redistribute it and/or modify
+00011  * it under the terms of the GNU General Public License as published by
+00012  * the Free Software Foundation; either version 2, or (at your option)
+00013  * any later version.
+00014 
+00015  * NEVRAX NEL is distributed in the hope that it will be useful, but
+00016  * WITHOUT ANY WARRANTY; without even the implied warranty of
+00017  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+00018  * General Public License for more details.
+00019 
+00020  * You should have received a copy of the GNU General Public License
+00021  * along with NEVRAX NEL; see the file COPYING. If not, write to the
+00022  * Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+00023  * MA 02111-1307, USA.
+00024  */
+00025 
+00026 #include "stdsound.h"
+00027 
+00028 #include "bounding_box.h"
+00029 #include "nel/misc/plane.h"
+00030 
+00031 using namespace NLMISC;
+00032 
+00033 namespace NLSOUND {
+00034 
+00035 
+00036 /*
+00037  * Constructor
+00038  */
+00039 CBoundingBox::CBoundingBox() : _Rx(0.0f), _Ry(0.0f), _Rz(0.0f), _Center(CVector::Null)
+00040 {
+00041 }
+00042 
+00043 
+00044 /*
+00045  * Does the box include a point ?
+00046  */
+00047 bool                    CBoundingBox::include( const CVector& pos ) const
+00048 {
+00049         if ( pos.x < _Center.x - _Rx ) return false;
+00050         if ( pos.x > _Center.x + _Rx ) return false;
+00051         if ( pos.y < _Center.y - _Ry ) return false;
+00052         if ( pos.y > _Center.y + _Ry ) return false;
+00053         if ( pos.z < _Center.z - _Rz ) return false;
+00054         if ( pos.z > _Center.z + _Rz ) return false;
+00055         return true;
+00056 }
+00057 
+00058 
+00059 /*
+00060  * Return the environment size
+00061  */
+00062 float                   CBoundingBox::getDiameter() const
+00063 {
+00064         // Set it to the average of the three widths (?)
+00065         return (_Rx+_Ry+_Rz) / 1.5f;
+00066 }
+00067 
+00068 
+00069 /*
+00070  * Return the radius at the intersection of the shape and the line between the specified position and the center of the shape
+00071  */
+00072 float                   CBoundingBox::getRadiusAtIntersect( const NLMISC::CVector& pos ) const
+00073 {
+00074         return 0.0f;
+00075 }
+00076 
+00077 
+00078 /*
+00079  *
+00080  */
+00081 CVector                 CBoundingBox::getIntersectWithLine( const NLMISC::CVector& c, const NLMISC::CVector& p ) const
+00082 {
+00083         // 1. Build 6 planes made up of the box
+00084         CPlane pl[6];
+00085         CVector ppos = _Center;
+00086         ppos.x = _Center.x + _Rx;
+00087         pl[0].make( CVector::I, ppos );
+00088         ppos.x = _Center.x - _Rx;
+00089         pl[1].make( -CVector::I, ppos );
+00090         ppos.x = _Center.x;
+00091         ppos.y = _Center.y + _Ry;
+00092         pl[2].make( CVector::J, ppos );
+00093         ppos.y = _Center.y - _Ry;
+00094         pl[3].make( -CVector::J, ppos );
+00095         ppos.y = _Center.y;
+00096         ppos.z = _Center.z + _Rz;
+00097         pl[4].make( CVector::K, ppos );
+00098         ppos.z = _Center.z - _Rz;
+00099         pl[5].make( -CVector::K, ppos );
+00100 
+00101         // 2. Maximize the length of the segment to be greater than the size of the box (>=sqrt(3))
+00102         CVector v = (p-c).normed();
+00103         v *= std::max( std::max( _Rx, _Ry ), _Rz ) * 10.0f;
+00104         CVector pfar = c + v;
+00105 
+00106         // 3. Clip
+00107         CVector center = c;
+00108         uint i;
+00109         for ( i=0; i!=6; ++i )
+00110         {
+00111                 pl[i].clipSegmentBack( center, pfar );
+00112         }
+00113 
+00114         return pfar;
+00115 }
+00116 
+00117 
+00118 /* Return the ratio of a point between this shape and another inner shape.
+00119  * The point must be included in this shape (the outer one) and not
+00120  * in the inner shape.
+00121  * If the point is near this shape, the ratio is near 0.
+00122  * If the point is near the inner shape, the ratio is near 1.
+00123  */
+00124 float                   CBoundingBox::getRatio( const NLMISC::CVector& pos, IBoundingShape *inner ) const
+00125 {
+00126         /* TEMP: works only with 2 boxes
+00127          *
+00128          */
+00129 
+00130         // Let C be the center of the inner shape, P the position of the point
+00131 
+00132         // 1. Get the intersection A between [CP] and the inner shape
+00133         CVector posa = inner->getIntersectWithLine( inner->getCenter(), pos );
+00134 
+00135         // 2. Get the intersection B between (CP) and the outer shape (this)
+00136         CVector posb = getIntersectWithLine( inner->getCenter(), pos );
+00137 
+00138         // 3. Compute PB / AB
+00139         float ab = (posa-posb).norm();
+00140         if ( ab != 0 )
+00141         {
+00142                 float pb = (pos-posb).norm();
+00143                 return pb / ab;
+00144         }
+00145         else
+00146         {
+00147                 return 1.0f;
+00148         }
+00149 }
+00150 
+00151 
+00152 /*
+00153  * Return the corners (EDIT)
+00154  */
+00155 void                    CBoundingBox::getCorners( NLMISC::CVector& c1, NLMISC::CVector& c2 )
+00156 {
+00157         c1.x = _Center.x - _Rx;
+00158         c1.y = _Center.y - _Ry;
+00159         c1.z = _Center.z - _Rz;
+00160         c2.x = _Center.x + _Rx;
+00161         c2.y = _Center.y + _Ry;
+00162         c2.z = _Center.z + _Rz;
+00163 }
+00164 
+00165 /*
+00166  * Set the corners (the corners must be ordered: 1 has smaller x, y, z) (EDIT)
+00167  */
+00168 void                    CBoundingBox::setCorners( const NLMISC::CVector& c1, const NLMISC::CVector& c2 )
+00169 {
+00170         _Center.x = (c1.x+c2.x)/2.0f;
+00171         _Center.y = (c1.y+c2.y)/2.0f;
+00172         _Center.z = (c1.z+c2.z)/2.0f;
+00173         _Rx = (c2.x-c1.x)/2.0f;
+00174         _Ry = (c2.y-c1.y)/2.0f;
+00175         _Rz = (c2.z-c1.z)/2.0f;
+00176 }
+00177 
+00178 
+00179 } // NLSOUND
+
bounding_box.cpp
