[Freeciv-Dev] Re: (PR#8864) Mapview common assumes that city descriptions are drawn into the mapview

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=8864 >

Jason Short wrote:
> <URL: http://rt.freeciv.org/Ticket/Display.html?id=8864 >
> 
> Raimar Falke wrote:
> 
>><URL: http://rt.freeciv.org/Ticket/Display.html?id=8864 >
>>
>>
>>See $SUBJECT. This assumption is incorrect for the FS client. This
>>causes problems with the update. If the mapview is moved (origin
>>changed) the city descriptions aren't redrawn.
> 
> 
> It is not possible (AFAICT) to make a *unified* design that works for 
> multiple-buffer and single-buffer city description drawing.  But it is 
> possible to make a design that works for single-buffer city description 
> drawing only.  And it's also possible to implement single-buffer drawing 
> for all GUIs.
> 
> So, why can't the FS client draw the city descriptions to the backing store?

It may be possible to hack around the design.  Update_map_canvas_visible 
does several copies to avoid excessive redraws.  We could tell the GUI 
about these copies and it could duplicated them for the city buffer.

But this is ugly and still doesn't fix everything (e.g. 
update_city_description still redraws the terrain under the text).  It 
would be better IMO to just write the text to the main buffer as the 
design prescribes.

jason