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

[Raimar Falke <hawk@xxxxxxxxxxxxxxxxxxxxxxx>]

On Fri, Aug 24, 2001 at 03:46:31PM -0400, Jason Dorje Short wrote:
> "Ross W. Wetmore" wrote:
> > 
> > Are there any GUI experts around?
> > 
> > IMHO, having the same position drawn more than once is an error. If
> > you stretch the canvas to exceed the base map size, I'm not sure
> > that seeing only a single valued map isn't the desired behaviour. If
> > there is a vote, I would vote for this, and not the other.
> > 
> > Resize, if ever implemented, may make the argument mute though.
> > 
> > I think the patch should NOT be applied until this is worked out.
> 
> As I said before, the current system is fundamentally flawed.  It just
> happens to get things right in most cases because normalize_map_pos does
> what it expects.  It is much more "correct" to do things this way and
> avoids many spurious normalizations.
> 
> Note that under the current system the same position *is* drawn more
> than once in the case of a wrap-around - but the two drawings of that
> position will be drawn one on top of each other in the same spot.
> 
> There is one problem with the improved system, which is what I described
> before.  

> Any time you're refreshing the canvas, you'll iterate over absolute
> map positions and use the normalized map positions to determine what
> to draw.  However, any time you have a specific update (for
> instance, of a unit) you only have the normal map positions to work
> with.  These need to be converted to absolute map positions for
> drawing - which isn't done right now.  The result is that the normal
> map positions are drawn to, which means (1) the update can happen in
> only one place on the mapview and (2) it may be possible for the
> update to happen outside the mapview, and not be shown at all.

Nice description of the problem.

> This is not IMO a reason to reject this bugfix; it just means that
> the other parts of the code need to be fixed as well.  In this case,
> the normal map positions need to be used to find all absolute map
> positions that need to be updated.
> 
> I don't see how you can argue that the mapview shouldn't wrap around. 
> Playing with the proper wrapping is much, much nicer than with improper
> wrapping!  The situation is rare enough that there shouldn't be much
> problem with having to update units multiple times, and again there will
> be the satisfaction of doing things the "right" way.
> 
> One problem I have with the current code is that it is duplicated
> line-for-line between many of the GUI interfaces.  Functions such as
> get_canvas_xy (and there are a _lot_ of others) really should be in the
> common client code (in client/).  However, right now the differences are
> just enough that this isn't immediately possible.  Instead of fixing the
> code in all different GUI's, I'd rather see code moved into the common
> area.  Obviously a certain degree of separation from the graphical
> routines is needed, which isn't present in much of the code right now
> (mostly the isometric code).

I have also came across this. So if you have any ideas/patches:
present them.

        Raimar

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