Acceleration of Box's Normal

 static void Box_Normal(VECTOR Result, OBJECT *Object, INTERSECTION *Inter)

  {
   switch (Inter->i1)
    {
     case SIDE_X_0: Make_Vector(Result, -1.0,  0.0,  0.0); break;
     case SIDE_X_1: Make_Vector(Result,  1.0,  0.0,  0.0); break;
     case SIDE_Y_0: Make_Vector(Result,  0.0, -1.0,  0.0); break;
     case SIDE_Y_1: Make_Vector(Result,  0.0,  1.0,  0.0); break;
     case SIDE_Z_0: Make_Vector(Result,  0.0,  0.0, -1.0); break;
     case SIDE_Z_1: Make_Vector(Result,  0.0,  0.0,  1.0); break;
     default: Error("Unknown box side in Box_Normal().\n");
    }

    /* Transform the point into the boxes space. */

   if (((BOX *)Object)->Trans != NULL)
    {
     MTransNormal(Result, Result, ((BOX *)Object)->Trans);
     VNormalize(Result, Result);
    }
 }


New code:


  static void Box_Normal(VECTOR Result, OBJECT *Object, INTERSECTION *Inter)
   {
    if (((BOX *)Object)->Trans == NULL )
     switch (Inter->i1)
      {
       case SIDE_X_0: Make_Vector(Result, -1.0,  0.0,  0.0); break;
       case SIDE_X_1: Make_Vector(Result,  1.0,  0.0,  0.0); break;
       case SIDE_Y_0: Make_Vector(Result,  0.0, -1.0,  0.0); break;
       case SIDE_Y_1: Make_Vector(Result,  0.0,  1.0,  0.0); break;
       case SIDE_Z_0: Make_Vector(Result,  0.0,  0.0, -1.0); break;
       case SIDE_Z_1: Make_Vector(Result,  0.0,  0.0,  1.0); break;
       default: Error("Unknown box side in Box_Normal().\n");
      }
    else
     switch (Inter->i1)
      {
       case SIDE_X_0: Assign_Vector(Result, ((BOX *)Object)->N_X_0); break;
       case SIDE_X_1: Assign_Vector(Result, ((BOX *)Object)->N_X_1); break;
       case SIDE_Y_0: Assign_Vector(Result, ((BOX *)Object)->N_Y_0); break;
       case SIDE_Y_1: Assign_Vector(Result, ((BOX *)Object)->N_Y_1); break;
       case SIDE_Z_0: Assign_Vector(Result, ((BOX *)Object)->N_Z_0); break;
       case SIDE_Z_1: Assign_Vector(Result, ((BOX *)Object)->N_Z_1); break;
       default: Error("Unknown box side in Box_Normal().\n");
      }
   }