Commit a4454e7e authored by Martin Reinecke's avatar Martin Reinecke
Browse files

add missing files

parent e5a4f4b2
/*
* This file is part of libcxxsupport.
*
* libcxxsupport 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.
*
* libcxxsupport 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 libcxxsupport; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* libcxxsupport is being developed at the Max-Planck-Institut fuer Astrophysik
* and financially supported by the Deutsches Zentrum fuer Luft- und Raumfahrt
* (DLR).
*/
/*
* Copyright (C) 2011-2020 Max-Planck-Society
* \author Martin Reinecke
*/
#include "mr_util/geom_utils.h"
#include "mr_util/error_handling.h"
using namespace std;
namespace mr {
namespace {
void get_circle (const vector<vec3> &point, size_t q1, size_t q2, vec3 &center,
double &cosrad)
{
center = (point[q1]+point[q2]).Norm();
cosrad = dotprod(point[q1],center);
for (size_t i=0; i<q1; ++i)
if (dotprod(point[i],center)<cosrad) // point outside the current circle
{
center=crossprod(point[q1]-point[i],point[q2]-point[i]).Norm();
cosrad=dotprod(point[i],center);
if (cosrad<0)
{ center.Flip(); cosrad=-cosrad; }
}
}
void get_circle (const vector<vec3> &point, size_t q, vec3 &center,
double &cosrad)
{
center = (point[0]+point[q]).Norm();
cosrad = dotprod(point[0],center);
for (size_t i=1; i<q; ++i)
if (dotprod(point[i],center)<cosrad) // point outside the current circle
get_circle(point,i,q,center,cosrad);
}
} // unnamed namespace
void find_enclosing_circle (const vector<vec3> &point, vec3 &center,
double &cosrad)
{
size_t np=point.size();
MR_assert(np>=2,"too few points");
center = (point[0]+point[1]).Norm();
cosrad = dotprod(point[0],center);
for (size_t i=2; i<np; ++i)
if (dotprod(point[i],center)<cosrad) // point outside the current circle
get_circle(point,i,center,cosrad);
}
}
/*
* This file is part of libcxxsupport.
*
* libcxxsupport 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.
*
* libcxxsupport 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 libcxxsupport; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* libcxxsupport is being developed at the Max-Planck-Institut fuer Astrophysik
* and financially supported by the Deutsches Zentrum fuer Luft- und Raumfahrt
* (DLR).
*/
/*! \file geom_utils.h
* Geometric utility functions.
*
* Copyright (C) 2003-2020 Max-Planck-Society
* \author Martin Reinecke
* \author Reinhard Hell
*/
#ifndef MRUTIL_GEOM_UTILS_H
#define MRUTIL_GEOM_UTILS_H
#include <vector>
#include "mr_util/math_utils.h"
#include "mr_util/vec3.h"
namespace mr {
/*! Returns the orientation when looking from point \a loc on the unit
sphere in the direction \a dir. \a loc must be normalized. The result
ranges from -pi to pi, is 0 for North and pi/2 for West, i.e. the angle
is given in mathematically positive sense.
If \a loc is the North or South pole, the returned angle is
\a atan2(dir.y,dir.x). */
inline double orientation (const vec3 &loc, const vec3 &dir)
{
// FIXME: here is still optimization potential
if (loc.x==0 && loc.y==0)
return (loc.z>0) ? safe_atan2(dir.y,-dir.x) : safe_atan2(dir.y,dir.x);
vec3 east (-loc.y, loc.x, 0);
vec3 north = crossprod(loc,east);
return safe_atan2(-dotprod(dir,east),dotprod(dir,north));
}
/*! Returns the angle between \a v1 and \a v2 in radians. */
inline double v_angle (const vec3 &v1, const vec3 &v2)
{
using namespace std;
return atan2 (crossprod(v1,v2).Length(), dotprod(v1,v2));
}
/*! Returns the cosine of the angle between the two points on the sphere defined
by (\a z1, \a phi1) and (\a z2, \a phi2), respectively. \a z is the cosine
of the colatitude, and \a phi is the longitude. */
inline double cosdist_zphi (double z1, double phi1, double z2, double phi2)
{
using namespace std;
return z1*z2+cos(phi1-phi2)*sqrt((1.-z1*z1)*(1.-z2*z2));
}
/*! Finds the smallest enclosing cone for a point set on the sphere according to
Barequet & Elber: Information Processing Letters 93(2005), p.83.
All points are expected to be passed as unit vectors.
The enclosing cone must have an opening angle <pi/2. */
void find_enclosing_circle (const std::vector<vec3> &point, vec3 &center,
double &cosrad);
}
#endif
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