[Freeciv-Dev] Re: Corecleanup patch updates

[Mike Kaufman <mkaufman@xxxxxxxxxxxxxx>]

On Sun, Aug 12, 2001 at 11:52:24PM -0400, Jason Dorje Short wrote:
> 
> The rest of your discussion is quite interesting, but not important as
> far as this question is concerned.

not sure where the question is...the _point_ is loud and clear.
> 
> To repeat: not even all rectangles allow for independent normalization
> of X and Y coordinates.  The orthogonal system proposed a few weeks ago
> was a simple rectangle tilted at a 45 degree angle so that it would
> appear flat with an orthogonal tileset.
> 
>   X X
> X X X X
>   X X X X
>     X X X X
>       X X X X
>         X X X X
>           X X
> 

If it were just rectangular maps like the one above, I would say that it 
wouldn't be worth the trouble, but I foresee slightly more complex topologies 
where wrapping of this type would be needed. 

If your claim is that more complex topologies will require different guts to 
normalize_map_pos(), I'm certainly not going to disagree with you (the guts of 
is_real_tile() would have to change too). 

int normalize_map_pos(int *x, int *y) {

  if(map.topology == RECT){
    if(!is_real_tile()) return FALSE;
    do this;
  }else if(map.topology == SPHERE){
    do that;
  }else if(map.toplogy == WEIRD){
    if(!is_real_tile()) return FALSE;
    etc;
  }
  ...
}

But under the present---and slightly future---system of flat, single and double 
wrap rectangular systems, we can normalize x and y independently. Until the 
underlying topology changes, lets not make things more difficult.

> Tilt your head 45 degrees to the right to see the rectangle; it then
> wraps off of the left and right sides.  Note that it is completely clean
> topologically, but there is no possible way to normalize X and Y
> coordinates independently because the axis of wrapping has components in
> both directions.
> 
> Incidentally, I would call this a 12x2 rectangle.

hmm, what would you call this:

     X
   X X X
 X X X X X
   X X X X X
     X X X X X
       X X X X X
         X X X
           X

-mike