//
//    File: geomview_mesh.cc
//
//    (C) 2000-2006 Helmut Cantzler
//
//    Licensed under the terms of the Lesser General Public License.
//

#include "geomview_mesh.h"

int Geomview_Mesh::read(FILE *f, int (*update_progress)(int pos),
		   void (*set_total)(int size))
{
  list<Triangle*> *shape_triangles;
  list<Vertex*> *shape_vertices;
  vector<Vertex*> vertex_index;
  int p1, p2, p3, i, v_nr, p_nr;
  float c1, c2, c3, c4;
  char nr; 
  float x, y, z;
  Triangle *tri;
  Vertex *v;

  fseek(f, 0, SEEK_END);
  (*set_total)(ftell(f));
  fseek(f, 0, SEEK_SET);

  while (fgetc(f) != '\n') // Reads all of the 1st line
    ;
  fscanf(f,"3\n"); // get optional 
                   // dimensionality value from header (i.e 3)
  
  if (fscanf(f,"%d %d", &v_nr, &p_nr) != 2) // Read vertices/polygons header
    // on failure try alternatives with OFF/COFF & vertices/polygons on same 
    // first line
  {		
      fseek(f, 0, SEEK_SET);
      if ((fscanf(f,"OFF %d %d", &v_nr, &p_nr) != 2) &&
	  (fscanf(f,"COFF %d %d", &v_nr, &p_nr) != 2)) // Read vertices/polygons header
      {
	  FILE_ERROR(f, "Geomview (OFF) header format error: cannot get vertex/polygon count");
	  return 2;
      }
  }
  while (fgetc(f) != '\n') // Reads till end of the line
    ;
  shape_triangles = new list<Triangle*>;
  shape_vertices = new list<Vertex*>;

  for (i=0; i < v_nr; i++) // Reads the vertices
    {
      if (fscanf(f,"%f %f %f",&x,&y,&z) != 3)
	  {
		FILE_ERROR(f, "Geomview (OFF) file format error: vertex list");
		return 3;
	  }
	  while (fgetc(f) != '\n'); // Read till end of the line
								// to skip texture/colour values
      v = new Vertex(x,y,z);
      add_vertex(v);

      // save in a vector for the triangles and shape
      vertex_index.push_back(v);

      if ((*update_progress)(ftell(f)))
		return 90;
    }

  while ((0 < p_nr) && (!(feof(f)))) /* Reads the polygons to end of file or max polys.*/
    {
    fscanf(f,"%c", &nr);
		
    switch (nr)
	{
	case '2':
	  if (fscanf(f,"%d %d\n", &p1, &p2) != 2)
	    {
	      FILE_ERROR(f, "Geomview (OFF) file format error: polygon 2");
	      return 6;
	    }
	  add_edge(new Edge(vertex_index[p1], vertex_index[p2]));
	  p_nr--;
	  break;

	case '3':
	  if (fscanf(f,"%d %d %d\n", &p1, &p2, &p3) != 3)
	    {
		  // if this fails then handle and ignore upto 4 colourspec values
		  if (
			(fscanf(f,"%d %d %d %f\n", &p1, &p2, &p3, &c1) != 4) &&
			(fscanf(f,"%d %d %d %f %f\n", &p1, &p2, &p3, 
						  &c1, &c2) != 5) &&
			(fscanf(f,"%d %d %d %f %f %f\n", &p1, &p2, &p3, 
						  &c1, &c2, &c3) != 6) &&
			(fscanf(f,"%d %d %d %f %f %f %f\n", &p1, &p2, &p3, 
						  &c1, &c2, &c3, &c4) != 7)
		      )
		  {
			  FILE_ERROR(f, "Geomview file format error: polygon 3");
			  return 7;
		  }
		}
		if ((p1 >= ver_nr) || (p2 >= ver_nr) || (p3 >= ver_nr)){
				FILE_ERROR(f, "Geomview file format error: vertex index out of range");
			  return 8;
		} 
	  tri = new Triangle(vertex_index[p1], vertex_index[p2],
					      vertex_index[p3]);
	  add_triangle(tri);
	  p_nr--;
	   // save in a list for the shape
	   shape_triangles->push_back(tri);
	  break;
		
    case '#': // skip comments
	  do
	    {
	      nr=fgetc(f);
	    }
	  while ((!(feof(f))) && nr != '\n');
	  break;
	case ' ':
	case '\t':
    case '\n':
	  // skip leading whitespace characters
	  break;
	default:
		// skip any lines that that we are not interested in
		// (i.e. don't begin with the cases above)
	    // e.g. N vertex polygons of form "N v1 v2...vN" on the line
	  	do 
	    {
	      nr=fgetc(f);
	    }
	    while ((!(feof(f))) && nr != '\n');
	  break;
	}
      
    if ((*update_progress)(ftell(f)))
		return 90;
    }

  // copy the vertices of this shape over
  shape_vertices->insert(shape_vertices->begin(), 
			 vertex_index.begin(), vertex_index.end());

  shapes->push_back(new Shape(shape_triangles, shape_vertices));

  return 0;
}

void Geomview_Mesh::write(FILE *f, const char *comment)
{
  int n;
  list<Triangle*>::iterator it;
  list<Vertex*>::iterator iv;
  Vertex v;

  // header
  fprintf(f,"OFF\n%d %d 0\n", ver_nr, tri_nr);

  n=0;   // vertices
  for (iv=vertices->begin(); iv != vertices->end(); iv++)
    {
      calc_original_coordinates(*iv, &v);
      fprintf(f,"%f %f %f\n", v.x(), v.y(), v.z());
      (*iv)->number=n;
      n++;
    }

  for (it=triangles->begin(); it != triangles->end(); it++)
    fprintf(f,"3 %d %d %d\n", (*it)->vertices[0]->number,
	    (*it)->vertices[1]->number, (*it)->vertices[2]->number);
}