[Freeciv-Dev] Re: [PATCH] bugfix for wrapping problem

[Raimar Falke <hawk@xxxxxxxxxxxxxxxxxxxxxxx>]

On Fri, Aug 24, 2001 at 02:01:43PM -0700, Trent Piepho wrote:
> On Fri, 24 Aug 2001, Ross W. Wetmore wrote:
> > If this is a bugfix, get someone knowledgable to validate it.
> 
> I wrote as much of the freeciv client as anyone, so I think I qualify as an
> expert.
> 
> Drawing the same tile multiple times if the map window is large enough to wrap
> around is the wrong thing to do.  It is what the client used to do, I first
> noticed that when I added support for different sized tiles.  I made some tiny
> 15x15 tiles that let me wrap around. 
> 
> It didn't work exactly right though, as when a unit moved it would only move
> one of the copies on the map.  The unit movement code would look for the
> position of the unit on the map canvas, then move it.  It didn't check if the
> unit was on the canvas twice and move it twice.  Same with pretty much all the
> code that updates the map, only one copy is updated.  The only reason it
> appears to work at first, is because the map refresh is triggered by the
> canvas tile. 
> 
> Getting a wrapped around map to work properly would be a major undertaking. 
> All the map update code assumes that in order to show X on the map, it just
> needs to find out where X is and draw it once.  Having to worry about finding
> all copies of X on the map and drawing each one of them would be a major pain
> in the ass to code.  No way is it worth it, especially for something that
> would be a visual nightmare.

So we still have to option of making a brute "refresh the whole
canvas" if the map wraps and only a single should be updated?!

        Raimar

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