#ifndef Polygon_H
#define Polygon_H

/* Last edited on 2007-02-04 16:17:06 by stolfi */

/* Procedures to build isolated {n}-sided polygons. */

#define Polygon_H_copyright \
  "Copyright © 2000 Universidade Estadual de Campinas (UNICAMP)"

#include <Octf.h>
#include <Triangulation.h>

#include <r4.h>
#include <vec.h>

Place_vec_t PolygonMake(uint n, bool_t nodes, bool_t edges, bool_t walls, bool_t cells);
  /* Builds a 3D map on the 3-sphere consisting of an isolated
    {n}-gon. The map has
      
      {n}   nodes (vertices, corners) {v[0..n-1]}
      {n}   edges (sides) {e[0..n-1]}
      1     wall {f}
      1     cell {c}
      
      {n}   wedges
      {4*n} places
      
    The single cell {c} incides on both sides of the single wall {f}.
    Edge {e[i]} connects node {v[i]} to node {v[(i+1)%n]}.
    
    Returns a vector {pv} where {pv.e[i]} is a place on edge {e[i]},
    flowing out of node {v[i]}. Thus {NextE(pv[i]) = pv[(i+1)%n]}.
    
    If {nodes} is TRUE, the procedure also creates the node data
    records and assigns them to the node data slots {OrgV(p)} of the
    appropriate places. If {nodes} is FALSE, all node slots are set to
    NULL. The meaning of parameters {edges}, {walls}, and {cells} is
    analogous. */

Place_t PolygonMakeSng(uint n);
  /* Same as {MakePolygon(n,TRUE,TRUE,TRUE,TRUE)} but returns only 
    one place {p}. */
  
void PolygonFixCoords(Place_t p, uint n, Coords_t *c);
  /* Assigns canonical coordinates to the corners of a wall {f =
    p.wall}, assumed to have {n} sides. Specifically, for {i} in
    {0..n-1} assigns to corner {v = OrgV(NextE^i(p))} of {f} the
    coordinates {{ cos(i*A), sin(i*A), 0, 0}} where {A=2*PI/n}.
    Assumes that the note pointer {OrgV(q)} is valid for every place
    {q} on {f}, and that the {num} fields of those nodes have distinct
    values in the range {0..c->ne-1}. */ 

#define Polygon_H_author \
  "C interface created by J. Stolfi, jan/2007."

#endif