//
//    File: obj_mesh.cc
//
//    (C) 2006 Toby Breckon / Helmut Cantzler
//
//    Licensed under the terms of the Lesser General Public License.
//

#include "obj_mesh.h"

int OBJ_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;
  Triangle *tri;
  Vertex *v;
  char type;
  int p1, p2, p3;
  float x, y, z;
	bool tri_parse_failure = FALSE;
	
  fseek(f, 0, SEEK_END);
  (*set_total)(ftell(f));
  fseek(f, 0, SEEK_SET);

  shape_triangles = new list<Triangle*>;
  shape_vertices = new list<Vertex*>;

  while ((type=fgetc(f)) != EOF)
    {
  switch (type)
        {
	case '#': // Comment
	  do    // Reads till end of the line
	    {
	      type=fgetc(f);
	    }
	  while (type != EOF && type != '\n');
	  break;

  case 'v': // Vertex
		
	  // check it is a vertex of "v" and not "vt" or "vn"
	
	  type=fgetc(f); 
	  if (type == ' '){
		  if (fscanf(f,"%f %f %f\n",&x,&y,&z) != 3)
      {
	      FILE_ERROR(f, "PMesh file format error: v");
	      return 3;
      }
		
			v = new Vertex(x,y,z);
			add_vertex(v);
		
			// save in a vector for the triangles and shape
			vertex_index.push_back(v);
    }
    break;

	case 'f': // Polygon with 3 vertices
	
		tri_parse_failure = FALSE;	
	
		// get first vertex	
	
		if (fscanf(f," %d", &p1) == 1) {
			do    // Reads till next space
	    {
	      type=fgetc(f);
	    }
	  	while (type != EOF && type != ' ');
		} else {
			tri_parse_failure = TRUE;
		}
	
		// get second vertex	
	
		if (fscanf(f,"%d", &p2) == 1) {
			do    // Reads till next space
	    {
	      type=fgetc(f);
	    }
	  	while (type != EOF && type != ' ');
		} else {
			tri_parse_failure = TRUE;
		}
		
		// get third vertex
		
		if (fscanf(f,"%d", &p3) == 1) {
			do    // Reads till next space
	    {
	      type=fgetc(f);
				
				// check we only have 3 vertices - i.e. it is a triangles
				
				if ((type != ' ') && (type != '\n') && (type != EOF)){ 
					tri_parse_failure = TRUE;
			 	}
	    }
	  	while (type != EOF && type != ' ' && type != '\n');
		} else {
			tri_parse_failure = TRUE;
		}
	  		
		if (!(tri_parse_failure))
			{
	 		 if (p1 < 1 || p2 < 1 || p3 < 1 ||
	     	  p1 > ver_nr || p2 > ver_nr || p3 > ver_nr)
        {
            FILE_ERROR(f, "OBJ file format error: wrong vertex index");
	          return 2;
        }
				tri = new Triangle(vertex_index[p1-1], vertex_index[p2-1],
							 vertex_index[p3-1]);
				add_triangle(tri);
		
				// save in a list for the shape
				shape_triangles->push_back(tri);

			}
	  break;

 default:
		// skip lines starting with all all other chars	
 		
 	    do    // Reads till end of the line
	    {
	      type=fgetc(f);
	    }
	  while (type != EOF && type != '\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 OBJ_Mesh::write(FILE *f, const char *comment)
{
  int n;
  list<Triangle*>::iterator it;
  list<Vertex*>::iterator iv;
  Vertex v;

  fprintf(f, "# produced by mview OBJ exporter\n");
  fprintf(f, "# %s\n", comment);
  fprintf(f, "\ng main\n");
	
  n=0;    // vertices
  for (iv=vertices->begin(); iv != vertices->end(); iv++)
    {
      calc_original_coordinates(*iv, &v);
      fprintf(f,"v %f %f %f\n", v.x(), v.y(), v.z());
      (*iv)->number=++n;
    }

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