/**********************************************************************

 *

 * PostGIS - Spatial Types for PostgreSQL

 * http://postgis.net

 *

 * PostGIS 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.

 *

 * PostGIS 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 PostGIS.  If not, see <http://www.gnu.org/licenses/>.

 *

 **********************************************************************

 *

 * Copyright (C) 2001-2006 Refractions Research Inc.

 *

 **********************************************************************/

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "liblwgeom_internal.h"

#include "lwgeom_log.h"

LWTIN* lwtin_add_lwtriangle(LWTIN *mobj, const LWTRIANGLE *obj)

{

  return (LWTIN*)lwcollection_add_lwgeom((LWCOLLECTION*)mobj, (LWGEOM*)obj);

}

void lwtin_free(LWTIN *tin)

{

  uint32_t i;

  if ( ! tin ) return;

  if ( tin->bbox )

    lwfree(tin->bbox);

  for ( i = 0; i < tin->ngeoms; i++ )

    if ( tin->geoms && tin->geoms[i] )

      lwtriangle_free(tin->geoms[i]);

  if ( tin->geoms )

    lwfree(tin->geoms);

  lwfree(tin);

}

void printLWTIN(LWTIN *tin)

{

  uint32_t i;

  LWTRIANGLE *triangle;

  if (tin->type != TINTYPE)

    lwerror("printLWTIN called with something else than a TIN");

  lwnotice("LWTIN {");

  lwnotice("    ndims = %i", (int)FLAGS_NDIMS(tin->flags));

  lwnotice("    SRID = %i", (int)tin->srid);

  lwnotice("    ngeoms = %i", (int)tin->ngeoms);

  for (i=0; i<tin->ngeoms; i++)

  {

    triangle = (LWTRIANGLE *) tin->geoms[i];

    printPA(triangle->points);

  }

  lwnotice("}");

}

/*

 * TODO rewrite all this stuff to be based on a truly topological model

 */

struct struct_tin_arcs

{

  double ax, ay, az;

  double bx, by, bz;

  uint32_t cnt, face;

};

typedef struct struct_tin_arcs *tin_arcs;

/* We supposed that the geometry is valid

   we could have wrong result if not */

int lwtin_is_closed(const LWTIN *tin)

{

  uint32_t i, j, k;

  uint32_t narcs, carc;

  int found;

  tin_arcs arcs;

  POINT4D pa, pb;

  LWTRIANGLE *patch;

  /* If surface is not 3D, it's can't be closed */

  if (!FLAGS_GET_Z(tin->flags)) return 0;

  /* Max theoretical arcs number if no one is shared ... */

  narcs = 3 * tin->ngeoms;

  arcs = lwalloc(sizeof(struct struct_tin_arcs) * narcs);

  for (i=0, carc=0; i < tin->ngeoms ; i++)

  {

    patch = (LWTRIANGLE *) tin->geoms[i];

    for (j=0; j < 3 ; j++)

    {

      getPoint4d_p(patch->points, j,   &pa);

      getPoint4d_p(patch->points, j+1, &pb);

      /* Make sure to order the 'lower' point first */

      if ( (pa.x > pb.x) ||

              (pa.x == pb.x && pa.y > pb.y) ||

              (pa.x == pb.x && pa.y == pb.y && pa.z > pb.z) )

      {

        pa = pb;

        getPoint4d_p(patch->points, j, &pb);

      }

      for (found=0, k=0; k < carc ; k++)

      {

        if (  ( arcs[k].ax == pa.x && arcs[k].ay == pa.y &&

                arcs[k].az == pa.z && arcs[k].bx == pb.x &&

                arcs[k].by == pb.y && arcs[k].bz == pb.z &&

                arcs[k].face != i) )

        {

          arcs[k].cnt++;

          found = 1;

          /* Look like an invalid TIN

                anyway not a closed one */

          if (arcs[k].cnt > 2)

          {

            lwfree(arcs);

            return 0;

          }

        }

      }

      if (!found)

      {

        arcs[carc].cnt=1;

        arcs[carc].face=i;

        arcs[carc].ax = pa.x;

        arcs[carc].ay = pa.y;

        arcs[carc].az = pa.z;

        arcs[carc].bx = pb.x;

        arcs[carc].by = pb.y;

        arcs[carc].bz = pb.z;

        carc++;

        /* Look like an invalid TIN

              anyway not a closed one */

        if (carc > narcs)

        {

          lwfree(arcs);

          return 0;

        }

      }

    }

  }

  /* A TIN is closed if each edge

         is shared by exactly 2 faces */

  for (k=0; k < carc ; k++)

  {

    if (arcs[k].cnt != 2)

    {

      lwfree(arcs);

      return 0;

    }

  }

  lwfree(arcs);

  /* Invalid TIN case */

  if (carc < tin->ngeoms) return 0;

  return 1;

}