// $Id: gmshSurface.cpp,v 1.8 2007-03-14 10:21:12 remacle Exp $
//
// Copyright (C) 1997-2007 C. Geuzaine, J.-F. Remacle
//
// 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.
// 
// Please report all bugs and problems to <gmsh@geuz.org>.

#include "gmshSurface.h"
#include "Message.h"
#if defined(HAVE_MATH_EVAL)
#include "matheval.h"
#endif

std::map<int,gmshSurface*> gmshSurface::allGmshSurfaces;

gmshSurface * gmshSphere::NewSphere(int iSphere, double x, double y, double z, double r)
{
  gmshSphere *sph = new gmshSphere(x, y, z, r);
  
  if(allGmshSurfaces.find(iSphere) != allGmshSurfaces.end()){
    Msg(GERROR,"gmshSurface %d already exists",iSphere);
  }
  
  allGmshSurfaces[iSphere] = sph;
  return sph;
}

gmshSurface * gmshSurface::surfaceByTag(int iSurface)
{
  std::map<int, gmshSurface*>::iterator it = allGmshSurfaces.find(iSurface);
  if(it == allGmshSurfaces.end()){
    Msg(GERROR,"gmshSurface %d does not exist",iSurface);
    return 0;
  }
  return it->second;
}

SPoint3  gmshSphere::point (double par1, double par2) const
{
  par2 += M_PI*.5;
  const double x = xc + r * sin(par2) * cos(par1);
  const double y = yc + r * sin(par2) * sin(par1);
  const double z = zc - r * cos(par2); 
  // printf("%g %g - %g %g %g\n",par1,par2,x,y,z);
  return SPoint3(x, y, z);
}

gmshSurface * gmshPolarSphere::NewPolarSphere(int iSphere, double x, double y, double z, double r)
{
  gmshPolarSphere *sph = new gmshPolarSphere(x, y, z, r);
  
  if(allGmshSurfaces.find(iSphere) != allGmshSurfaces.end()){
    Msg(GERROR,"gmshSurface %d already exists",iSphere);
  }
  
  allGmshSurfaces[iSphere] = sph;
  return sph;
}
SPoint3  gmshPolarSphere::point (double parA, double parB) const
{
	//stereographic projection from the south pole, origin of the axis at the center of the sphere
	//parA=2rx/(r+z)
	//parB=2ry/(r+z)
	double rp2=parA*parA+parB*parB;
	double z=r*(4*r*r-rp2)/(4*r*r+rp2);
  return SPoint3((r+z)*parA/(2*r),(r+z)*parB/(2*r),z);
}


gmshSurface * gmshParametricSurface::NewParametricSurface(int iSurf,  char *valX,  char *valY,  char *valZ)
{
  gmshParametricSurface *sph = new gmshParametricSurface(valX,valY,valZ);
  
  if(allGmshSurfaces.find(iSurf) != allGmshSurfaces.end()){
    Msg(GERROR,"gmshSurface %d already exists",iSurf);
  }
  allGmshSurfaces[iSurf] = sph;
  return sph;
}

gmshParametricSurface ::gmshParametricSurface(char *valX, char *valY, char *valZ)
{
#if !defined(HAVE_MATH_EVAL)
  Msg(GERROR, "MathEval is not compiled in this version of Gmsh");
#else
  evalX = evaluator_create(valX);
  evalY = evaluator_create(valY);
  evalZ = evaluator_create(valZ);
#endif
}

gmshParametricSurface ::~gmshParametricSurface()
{
#if !defined(HAVE_MATH_EVAL)
  Msg(GERROR, "MathEval is not compiled in this version of Gmsh");
#else
  evaluator_destroy(evalX);
  evaluator_destroy(evalY);
  evaluator_destroy(evalZ);
#endif
}
SPoint3 gmshParametricSurface ::point(double par1, double par2) const
{
#if !defined(HAVE_MATH_EVAL)
  Msg(GERROR, "MathEval is not compiled in this version of Gmsh");
#else
  char *names[2] = {"u","v"};
  double values [2] = {par1,par2};
  const double x = evaluator_evaluate(evalX, 2, names, values);
  const double y = evaluator_evaluate(evalY, 2, names, values);
  const double z = evaluator_evaluate(evalZ, 2, names, values);
  return SPoint3(x,y,z);
#endif
}