[Freeciv-Dev] Re: (PR#81) overstretched map doesn't get updated properly

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

Mike Kaufman wrote:
> On Fri, Jul 25, 2003 at 12:14:24AM -0700, Jason Short wrote:
> 
>>This actually happens because of a bug in map_to_canvas_pos for non-iso
>>view.
>>
>>If map_view_x0 = 0 then map_to_canvas_pos with x=20 will give you
>>canvas_x=20*NORMAL_TILE_WIDTH.  But x=100 will not give you
>>canvas_x=20*NORMAL_TILE_WIDTH the way it should - it will give
>>canvas_x=100*NORMAL_TILE_WIDTH.  Thus the tile will be erronously drawn
>>twice (erronously because it doesn't happen anywhere else and thus is
>>never updated).
>>
>>This is fixed by PR#4681.
>>
>>PR#4679 is also related - it leads to city names (but not whole tiles)
>>being drawn and never updated
> 
> 
> put my mind at ease here: we are not recinding the rule that tiles only get
> drawn once?

No, we are enforcing this rule.  Currently it is ignored in this one place.

See the earlier PR#81 discussion for a screenshot.  To be more accurate, 
the tile will be drawn twice during the iteration - we just need to make 
sure it's drawn in the same place both times.

Personally, I think it is better to draw tiles twice - especially after 
having played a few games on 40-25 iso-maps that wrap in both 
directions.  But it is infeasible to do it correctly, and doing it 
partially just leads to bugs like the original PR#81.

jason