libsegl/emath_opengl.cpp

100 lines
2.7 KiB
C++

/* libsegl - Sebas Extended GL Library
* Collection of Opengl/3D-Math helpers
*
* Copyright (c) 2008 by Sebastian Lohff, seba@seba-geek.de
* http://www.seba-geek.de
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "emath_opengl.h"
namespace segl {
void rotFrom2VecTo2Vec(Punkt3D a, Punkt3D b, Punkt3D c, Punkt3D d, Punkt3D *rvec, float *rvecdeg, Punkt3D *rvec2, float *rvecdeg2) {
Punkt3D rotvec, rotvec2, nullvec;
float rotvecdeg = 0.0f, rotvecdeg2 = 0.0f;
rotvec = a.kreuzprodukt(b);
rotvecdeg = a.calcAngle(b);
if(std::abs(rotvecdeg)==180.0f) {
rotvec = a.getOrtographic();
}
if(rotvec==nullvec) {
rotvec.set(1.0f, 0.0f, 0.0f);
rotvecdeg = 0.0f;
}
Rotationsmatrix rotnobj(rotvec, -rotvecdeg);
c = Rotationsmatrix(rotvec, rotvecdeg) * c;
rotvec2 = c.kreuzprodukt(d);
rotvecdeg2 = c.calcAngle(d);
if(std::abs(rotvecdeg2)==180.0f) {
rotvec2 = b;
}
if(rotvec2==nullvec) {
rotvec2.set(1.0f, 0.0f, 0.0f);
rotvecdeg2 = 0.0f;
}
rotvec2 = rotnobj * rotvec2;
*rvec = rotvec;
*rvecdeg = rotvecdeg;
*rvec2 = rotvec2;
*rvecdeg2 = rotvecdeg2;
}
void rotFrom2VecTo2Vec(Punkt3D a, Punkt3D b, Punkt3D c, Punkt3D d) {
Punkt3D rvec, rvec2;
float rvecdeg, rvecdeg2;
rotFrom2VecTo2Vec(a, b, c, d, &rvec, &rvecdeg, &rvec2, &rvecdeg2);
// if(rvecdeg)
glRotatef(rvecdeg, rvec);
// if(rvecdeg2)
glRotatef(rvecdeg2, rvec2);
// std::cout << rvecdeg << ", " << rvecdeg2 << std::endl;
// rvec.print("rvecdeg");
// rvec2.print("rvecdeg2");
}
void rotvec2(Punkt3D a, Punkt3D b, Punkt3D c, Punkt3D d, float *dega, Punkt3D *veca, float *degb, Punkt3D *vecb) {
*dega = a.calcAngle(b);
if(*dega==180.0f)
*veca = a.getOrtographic();
else if(*dega==0.0f)
veca->set(1.0f, 0.0f, 0.0f);
else
*veca = a.kreuzprodukt(b);
*degb = 0.0f;
vecb->set(1.0f, 0.0f, 0.0f);
c = Rotationsmatrix(*veca, *dega) * c;
*degb = c.calcAngle(d);
if(*degb==180.0f)
*vecb = c.getOrtographic();
else if(*degb==0.0f)
vecb->set(1.0f, 0.0f, 0.0f);
else
*vecb = c.kreuzprodukt(d);
}
} // namespace segl