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/*
* plane.cc -- ePiX::Plane class and mathematical operators
*
* This file is part of ePiX, a C++ library for creating high-quality
* figures in LaTeX
*
* Version 1.2.2
* Last Change: December 06, 2007
*/
/*
* Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
* Andrew D. Hwang <rot 13 nujnat at zngupf dot ubylpebff dot rqh>
* Department of Mathematics and Computer Science
* College of the Holy Cross
* Worcester, MA, 01610-2395, USA
*/
/*
* ePiX 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.
*
* ePiX 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 ePiX; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "constants.h"
#include "errors.h"
#include "curves.h" // for draw()
#include "plane.h"
namespace ePiX {
const double INF(2*EPIX_INFTY);
Plane::Plane(const P& pt, const P& perp)
: m_pt(pt), m_perp(perp), m_malformed(false)
{
double temp(norm(perp));
if (temp < EPIX_EPSILON)
{
epix_warning("Degenerate plane normal, using (0,0,1)");
m_perp=E_3;
}
else
m_perp *= 1.0/temp;
}
Plane::Plane(const P& p1, const P& p2, const P& p3)
: m_pt(p1), m_malformed(false)
{
P perp((p2-p1)*(p3-p1));
double norm_perp(norm(perp));
if (norm_perp < EPIX_EPSILON)
{
epix_warning("Collinear points in Plane constructor");
m_malformed = true;
}
else
m_perp = (1/norm_perp)*perp;
}
P Plane::pt() const
{
return m_pt;
}
P Plane::perp() const
{
return m_perp;
}
bool Plane::malformed() const
{
return m_malformed;
}
// translate
Plane& Plane::shift(const P& arg)
{
if (!m_malformed)
m_pt += arg;
return *this;
}
Plane& Plane::move_to(const P& arg)
{
if (!m_malformed)
m_pt = arg;
return *this;
}
void Plane::draw() const
{
if (m_malformed)
return;
// else
const P ctr((m_pt|m_perp)*m_perp); // closest point to origin
// construct an orthonormal basis
P e1(m_perp*E_1);
if (norm(e1) < 0.7) // ~sqrt(0.5)
e1 = m_perp*E_2;
e1 *= 1.0/norm(e1);
P e2(m_perp*e1);
// very large rectangle
quad(ctr + INF*( e1 + e2), ctr + INF*(-e1 + e2),
ctr + INF*(-e1 - e2), ctr + INF*( e1 - e2));
}
//// global functions ////
void plane(const P& point, const P& normal)
{
Plane pl(point, normal);
pl.draw();
}
void plane(const P& p1, const P& p2, const P& p3)
{
Plane pl(p1, p2, p3);
pl.draw();
}
} // end of namespace
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