struct marker
{
   float x, y, z;
};

void CalculateNormal(marker* normal, marker o, marker b, marker c)
{
   b.x = b.x - o.x;
   b.y = b.y - o.y;
   b.z = b.z - o.z;

   c.x = c.x - o.x;
   c.y = c.y - o.y;
   c.z = c.z - o.z;

/* Cross Product. */
   normal->x = (b.y * c.z) - (b.z * c.y);
   normal->y = (b.z * c.x) - (b.x * c.z);
   normal->z = (b.x * c.y) - (b.y * c.x);

/* Normalise. */
   float length = sqrt(normal->x * normal->x + normal->y * normal->y + normal->z * normal->z);
   normal->x = normal->x / length;
   normal->y = normal->y / length;
   normal->z = normal->z / length;

   return;
}

#define COLINEAR        0x00
#define CLOCKWISE       0x01
#define ANTICLOCKWISE   0x02

int TriangleOrientation(marker a, marker b, marker c)
{
   double determinant = (b.x - a.x) * (c.y - a.y) - (b.y - a.y) * (c.x - a.x);
   int result = COLINEAR;

   if (determinant < 0)
   {
      result = CLOCKWISE;
   }

   if (determinant > 0)
   {
      result = ANTICLOCKWISE;
   }

   return result;
}

/* Load a RAW file of triangle points. */
void LoadRAW(char* szFileName, float scale, marker* m, marker* normal, int& n)
{
	FILE* file = fopen(szFileName, "r");
   int ch = 0;

   n = 0;

	if (file != NULL)
   {
      ch = getc(file);

	   while (ch != EOF)
      {
         ungetc(ch, file);
         fscanf(file, "%f %f %f %f %f %f %f %f %f\n", &m[n + 0].x,
                                                      &m[n + 0].y,
                                                      &m[n + 0].z,
                                                      &m[n + 1].x,
                                                      &m[n + 1].y,
                                                      &m[n + 1].z,
                                                      &m[n + 2].x,
                                                      &m[n + 2].y,
                                                      &m[n + 2].z);

         m[n + 0].x = m[n + 0].x * scale; /* Scale the model. */
         m[n + 0].y = m[n + 0].y * scale;
         m[n + 0].z = m[n + 0].z * scale;
         m[n + 1].x = m[n + 1].x * scale;
         m[n + 1].y = m[n + 1].y * scale;
         m[n + 1].z = m[n + 1].z * scale;
         m[n + 2].x = m[n + 2].x * scale;
         m[n + 2].y = m[n + 2].y * scale;
         m[n + 2].z = m[n + 2].z * scale;

         if (TriangleOrientation(m[n + 0], m[n + 1], m[n + 2]) == CLOCKWISE)
         {
            marker t = m[n + 0]; // Help here!
            m[n + 0] = m[n + 2]; // Help here!
            m[n + 2] = t;        // Help here!
         }

         CalculateNormal(&normal[n], m[n + 0], m[n + 1], m[n + 2]);
         
         n = n + 3;

         ch = getc(file);
      }

      fclose(file);
   }
     
   return;
}