libsegl/emath_opengl.cpp

/* 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