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

[Raimar Falke <hawk@xxxxxxxxxxxxxxxxxxxxxxx>]

On Thu, Aug 30, 2001 at 03:29:44AM -0400, Jason Dorje Short wrote:
> "Ross W. Wetmore" wrote:
> > 
> > At 10:10 AM 01/08/29 +0200, Raimar Falke wrote:
> 
> > >You have to acknowledge that casting to unsigned and comparing it is a
> > >trick to gain performance and this trick isn't immediate obvious to a
> > >normal programmer. It has to be documented somewhere or we went up
> > >like in the ai case.
> > 
> > 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?

For a limited map the map can be shifted to have only position
coordinates. IMHO it isn't necessary to add flexibility here.

        Raimar

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