[Freeciv-Dev] Re: (PR#3936) introducing native coordinates

["Raimar Falke" <rf13@xxxxxxxxxxxxxxxxx>]

On Fri, Apr 04, 2003 at 07:48:14PM -0800, Jason Short wrote:
> 
> This is a significant design issue, and should be closely scrutinized. 
> I'd encourage everyone to at least read this patch.
> 
> Native coordinates (sometimes called "compressed" coordinates in the
> past) are a concept Ross came up with to make isometric (and other
> non-standard) maps easier to deal with.  They save around 50% memory
> (and on disk, in savegames) for map storage over "standard" map
> coordinates and make topology operations *much* simpler.  Other
> coordinate systems may share one of these properties, but none have
> both.  In the process, they invalidate the need for "regular" map positions.
> 
> The patch introduces native_to_map_pos and map_to_native_pos macros into
> map.h, along with one very simple user.  I've also written an
> explanation of the coordinate systems for doc/HACKING.  I'd like
> feedback on this explanation, particularly from people who don't already
> know what "native coordinates" are.
> 
> All other explanation is in the patch (or if it isn't, it should be).

What operations (would) require native coordinates? I have the feeling
that a lot can be done with indexed coordinates. For example
savegames. AFAIK there is no sane way to represent an iso-map in the
2d layout we have in savegames?! If this is true I would for example
rather go with indexed coordinates in savegames and remove the 2d
layout. If this is true the gamelog does have the same
problem. Wouldn't it be better for the gamelog to use this
representation

> +      X X X
> +       X X X
> +      X X X

??

        Raimar

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