// Vertex and Face data structure used in the mesh reader
// Feel free to change them
typedef struct _point {
  float x,y,z;
} point;

typedef struct _color {
  float r,g,b;
} color;

typedef struct _faceStruct {
  int c;
  int NumVerts;
  int *v;
} faceStruct;

int verts, faces, colors;  // Number of vertices, faces, and colors

color *colorList; // Color List
point *vertList; // Vertex List
faceStruct *faceList;	    // Face List

// The mesh reader itself
// It can read *very* simple obj files
void meshReader (char *filename,int sign)
{
  float x,y,z,len;
  int i,j;
  char letter;
  int ic,iv;
  FILE *fp;
  char line[100];

  fp = fopen(filename, "r");
  if (fp == NULL) { 
    printf("Cannot open %s\n!", filename);
    exit(0);
  }

  // Count the number of vertices and faces
  while(!feof(fp))
    {	
      letter = 'n';
      fscanf(fp,"%c",&letter);
      if (letter == 'c')
	{
	  colors++;
	}
      else if (letter == 'v')
	{
	  verts++;
	}
      else if (letter == 'f')
	{
	  faces++;
	}
      if (fgets(line,100,fp) == NULL)
	{
	  continue;
	}
    }

  fclose(fp);

  printf("colors : %d\n", colors);
  printf("verts : %d\n", verts);
  printf("faces : %d\n", faces);

  if (colors > 0)
    {
      // Dynamic allocation of vertex and face lists
      faceList = (faceStruct *)malloc(sizeof(faceStruct)*faces);
      vertList = (point *)malloc(sizeof(point)*verts);
      colorList = (color *)malloc(sizeof(color)*colors);

      fp = fopen(filename, "r");

  // Read the colors
      for(i = 0;i < colors;i++)
	{
	  fscanf(fp,"%c %f %f %f\n",&letter,&x,&y,&z);
	  colorList[i].r = x;
	  colorList[i].g = y;
	  colorList[i].b = z;
	}

      // Read the vertices
      for(i = 0;i < verts;i++)
	{
	  fscanf(fp,"%c %f %f %f\n",&letter,&x,&y,&z);
	  vertList[i].x = x;
	  vertList[i].y = y;
	  vertList[i].z = z;
	}

      // Read the faces
      for(i = 0;i < faces;i++)
	{
	  fscanf(fp,"%c %d %d",&letter,&ic,&(faceList[i].NumVerts));
	  faceList[i].c = ic - 1;
	  faceList[i].v = (int *)malloc(sizeof(int)*faceList[i].NumVerts);
	  for (j=0; j< faceList[i].NumVerts; j++)
	    {
	      fscanf(fp," %d",&iv);
	      faceList[i].v[j] = iv - 1;
	    }
	  fscanf(fp,"\n",&iv);
	}
    }
  else
    {
      colors = faces;
      // Dynamic allocation of vertex and face lists
      faceList = (faceStruct *)malloc(sizeof(faceStruct)*faces);
      vertList = (point *)malloc(sizeof(point)*verts);
      colorList = (color *)malloc(sizeof(color)*colors);

      // Create a random array of colors
      for(i = 0;i < colors;i++)
	{
	  colorList[i].r = ((float)rand())/((float)RAND_MAX);
	  colorList[i].g = ((float)rand())/((float)RAND_MAX);
	  colorList[i].b = ((float)rand())/((float)RAND_MAX);
	}

      fp = fopen(filename, "r");
      // Read the veritces
      for(i = 0;i < verts;i++)
	{
	  fscanf(fp,"%c %f %f %f\n",&letter,&x,&y,&z);
	  vertList[i].x = x;
	  vertList[i].y = y;
	  vertList[i].z = z;
	}

      // Read the faces
      for(i = 0;i < faces;i++)
	{
	  fscanf(fp,"%c",&letter);
	  faceList[i].c = i;
	  faceList[i].NumVerts = 3;
	  faceList[i].v = (int *)malloc(sizeof(int)*faceList[i].NumVerts);
	  for (j=0; j< faceList[i].NumVerts; j++)
	    {
	      fscanf(fp," %d",&iv);
	      faceList[i].v[j] = iv - 1;
	    }
	  fscanf(fp,"\n");
	}
      
    }
  fclose(fp);

}