[Freeciv-Dev] Re: [PATCH] Corecleanup_07Part2 has been putin incoming

["Ross W. Wetmore" <rwetmore@xxxxxxxxxxxx>]

At 03:29 AM 01/08/30 -0400, Jason Dorje Short wrote:
>"Ross W. Wetmore" wrote:
>> No, it can be viewed as *understanding* that real map coordinates are
>> always positive and defined by an upper bound and doing the appropriate
>> logical test for this condition. It is unfortunate that map coordinates
>> were stored in ints instead of unsigned, but the cast corrects this.
>
>Please, no!  Many topologies (notably the isometric ones) would be best
>handled if the map coordinates went over into the negatives.  A front
>end drawing a game may often want to draw negative tiles (irrelevant to
>the implementation, perhaps, but important to the theory).  Under the
>current topology, any negative X values doesn't prevent the tile from
>being real - only the Y value matters.
>
>Negative values are key.  We're talking about a plane; it extends
>forever in every direction.  We could have negative values wrap around
>to very high positive ones, but what would be the point, really?
>
>In the current topology no negative value can ever be normal.  Is this
>what you meant to say?
>
>jason

Change the "real map coordinates" to "as practically implemented real ...".

Most array programming doesn't use negative offsets. I think this sort of 
went out of style with PL1.

And note that a simple linear transformation reduces your case to the 
practical one that fits the programming model, so there is no loss of
"theoretical" reality.

Cheers,
RossW