[Freeciv-Dev] Re: (PR#8852) savefile positions should all be native

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=8852 >

rwetmore@xxxxxxxxxxxx wrote:

> I thought your were discussing changes to starting positions, and not map
> savegames. The two are not the same, and one should carefully look at where 
> they arise if you want to change this.

But starting positions are stored in the savegames.  Of course they are 
not the same...one is a set of coordinates and nations, the other is a 
file on disk...

> Your hangup with presentation level concepts polluting core elements is 
> making things difficult. Please try to understand the subtle difference 
> between native coordinates and where they are used, and GUI or presentation 
> level concepts and where they need be used.

Natural coordinates have use outside of the GUI, because they provide 
the correct aspect at a global scale.  This can be useful for mapgen, 
for instance.

>>2.  A patch is a request for a change.
>>
>>So my question is, what is your suggestion for fixing this?
>>
>>One idea I had was that the savegame could specify what type of 
>>coordinates it used.
> 
> No!  Always store savegames in native coordinates where the actual form of 
> the native *is* topology specific and coded for core storage efficiencies 
> and other considerations such as a compact rectangular debugging view of the 
> map. It should *never* be stored in user presentation forms like natural, 
> and we have already gone through the bounding box issues with map forms to 
> exclude them.

So you do agree the savegame should use native coordinates, then?

>>[map]
>>coordinates="native"
>>
>>Where "native", "natural", or "map" is specified.  A single function 
>>could then be used for loading tile positions, in whatever coordinate 
>>system is specified.
>>
>>The only real advantage I see to this is that it can work with imported 
>>savegames that use a different coordinate system.
> 
> This doesn't make sense. Try rewording for my mental limitations ...
> 
> The main use of savegames is to store compact information that doesn't keep 
> overflowing Ranier's servers, not giving users and certainly not developers 
> pretty GUI views.

Say someone converted a savegame from another civ program for use with 
freeciv.  This other civ program uses natural coordinates.  It would be 
very slightly helpful to be able to import it using natural coordinates 
rather than having to convert.

Note your argument of storage size is only an issue for the tile data, 
which is pretty hard-coded into a native form.  I haven't suggested 
changing this (although using different coordinates for the other 
elements without changing it is fairly useless).  However your storage 
size issue is a poor argument anyway since if we wanted to save size, we 
could do it far more easily with a binary savegame format.  At some 
point human readability of the savegame becomes more important than 
saving a few bytes.

jason