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/**
* $Id: RAS_texmatrix.cpp 14444 2008-04-16 22:40:48Z hos $
* ***** BEGIN GPL LICENSE BLOCK *****
*
* This program 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 2
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
* All rights reserved.
*
* The Original Code is: all of this file.
*
* Contributor(s): none yet.
*
* ***** END GPL LICENSE BLOCK *****
*/
#include "RAS_TexMatrix.h"
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
void RAS_CalcTexMatrix(RAS_TexVert p[3],MT_Point3& origin,MT_Vector3& udir,MT_Vector3& vdir)
{
// precondition: 3 vertices are non-colinear
MT_Vector3 vec1 = p[1].xyz()-p[0].xyz();
MT_Vector3 vec2 = p[2].xyz()-p[0].xyz();
MT_Vector3 normal = vec1.cross(vec2);
normal.normalize();
// determine which coordinate we drop, ie. max coordinate in the normal
int ZCOORD = normal.closestAxis();
int XCOORD = (ZCOORD+1)%3;
int YCOORD = (ZCOORD+2)%3;
// ax+by+cz+d=0
MT_Scalar d = -p[0].xyz().dot(normal);
MT_Matrix3x3 mat3( p[0].getUV1()[0],p[0].getUV1()[1], 1,
p[1].getUV1()[0],p[1].getUV1()[1], 1,
p[2].getUV1()[0],p[2].getUV1()[1], 1);
MT_Matrix3x3 mat3inv = mat3.inverse();
MT_Vector3 p123x(p[0].xyz()[XCOORD],p[1].xyz()[XCOORD],p[2].xyz()[XCOORD]);
MT_Vector3 resultx = mat3inv*p123x;
MT_Vector3 p123y(p[0].xyz()[YCOORD],p[1].xyz()[YCOORD],p[2].xyz()[YCOORD]);
MT_Vector3 resulty = mat3inv*p123y;
// normal[ZCOORD] is not zero, because it's chosen to be maximal (absolute), and normal has length 1,
// so at least on of the coords is <> 0
//droppedvalue udir.dot(normal) =0
MT_Scalar droppedu = -(resultx.x()*normal[XCOORD]+resulty.x()*normal[YCOORD])/normal[ZCOORD];
udir[XCOORD] = resultx.x();
udir[YCOORD] = resulty.x();
udir[ZCOORD] = droppedu;
MT_Scalar droppedv = -(resultx.y()*normal[XCOORD]+resulty.y()*normal[YCOORD])/normal[ZCOORD];
vdir[XCOORD] = resultx.y();
vdir[YCOORD] = resulty.y();
vdir[ZCOORD] = droppedv;
// droppedvalue b = -(ax+cz+d)/y;
MT_Scalar droppedvalue = -((resultx.z()*normal[XCOORD] + resulty.z()*normal[YCOORD]+d))/normal[ZCOORD];
origin[XCOORD] = resultx.z();
origin[YCOORD] = resulty.z();
origin[ZCOORD] = droppedvalue;
}
#ifdef _TEXOWNMAIN
int main()
{
MT_Point2 puv0={0,0};
MT_Point3 pxyz0 (0,0,128);
MT_Scalar puv1[2]={1,0};
MT_Point3 pxyz1(128,0,128);
MT_Scalar puv2[2]={1,1};
MT_Point3 pxyz2(128,0,0);
RAS_TexVert p0(pxyz0,puv0);
RAS_TexVert p1(pxyz1,puv1);
RAS_TexVert p2(pxyz2,puv2);
RAS_TexVert vertices[3] =
{
p0,
p1,
p2
};
MT_Vector3 udir,vdir;
MT_Point3 origin;
CalcTexMatrix(vertices,origin,udir,vdir);
MT_Point3 testpoint(128,32,64);
MT_Scalar lenu = udir.length2();
MT_Scalar lenv = vdir.length2();
MT_Scalar testu=((pxyz2-origin).dot(udir))/lenu;
MT_Scalar testv=((pxyz2-origin).dot(vdir))/lenv;
return 0;
}
#endif // _TEXOWNMAIN
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