quadrilateralcowboy/idlib/math/Pluecker.cpp

87 lines
3.0 KiB
C++

/*
===========================================================================
Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company.
This file is part of the Doom 3 GPL Source Code (?Doom 3 Source Code?).
Doom 3 Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Doom 3 Source Code 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 Doom 3 Source Code. If not, see <http://www.gnu.org/licenses/>.
In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code. If not, please request a copy in writing from id Software at the address below.
If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
===========================================================================
*/
#include "../precompiled.h"
#pragma hdrstop
idPluecker pluecker_origin( 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f );
/*
================
idPluecker::FromPlanes
pluecker coordinate for the intersection of two planes
================
*/
bool idPluecker::FromPlanes( const idPlane &p1, const idPlane &p2 ) {
p[0] = -( p1[2] * -p2[3] - p2[2] * -p1[3] );
p[1] = -( p2[1] * -p1[3] - p1[1] * -p2[3] );
p[2] = p1[1] * p2[2] - p2[1] * p1[2];
p[3] = -( p1[0] * -p2[3] - p2[0] * -p1[3] );
p[4] = p1[0] * p2[1] - p2[0] * p1[1];
p[5] = p1[0] * p2[2] - p2[0] * p1[2];
return ( p[2] != 0.0f || p[5] != 0.0f || p[4] != 0.0f );
}
/*
================
idPluecker::Distance3DSqr
calculates square of shortest distance between the two
3D lines represented by their pluecker coordinates
================
*/
float idPluecker::Distance3DSqr( const idPluecker &a ) const {
float d, s;
idVec3 dir;
dir[0] = -a.p[5] * p[4] - a.p[4] * -p[5];
dir[1] = a.p[4] * p[2] - a.p[2] * p[4];
dir[2] = a.p[2] * -p[5] - -a.p[5] * p[2];
if ( dir[0] == 0.0f && dir[1] == 0.0f && dir[2] == 0.0f ) {
return -1.0f; // FIXME: implement for parallel lines
}
d = a.p[4] * ( p[2]*dir[1] - -p[5]*dir[0]) +
a.p[5] * ( p[2]*dir[2] - p[4]*dir[0]) +
a.p[2] * (-p[5]*dir[2] - p[4]*dir[1]);
s = PermutedInnerProduct( a ) / d;
return ( dir * dir ) * ( s * s );
}
/*
=============
idPluecker::ToString
=============
*/
const char *idPluecker::ToString( int precision ) const {
return idStr::FloatArrayToString( ToFloatPtr(), GetDimension(), precision );
}