[Freeciv-Dev] Re: (PR#7287) Extended Topologies(PR#6721)

["Marcelo Burda" <NOSPAM_mburda@xxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=7287 >

Le lun 23/02/2004 à 16:07, Ross Wetmore a écrit :
> Jason Short wrote:
> > <URL: http://rt.freeciv.org/Ticket/Display.html?id=7287 >
> > 
> > Marcelo Burda wrote:
> > 
> >>>Consider also that the extended topologies come in several forms.  For 
> >>>instance an offset-wrap as I describe it above will probably not take 
> >>>much work to implement, but gives only a small advantage over the 
> >>>current torus wrapping.  A quincuncial wrapping will take a fair amount 
> >>>of work to implement.  It is of high theoretical interest (how many 
> >>>hours have we spent discussing approximations of a sphere?) but its 
> >>>playability hasn't been determined.  People need to _play_ this thing 
> >>>before we can assess it.
> >>
> >>the last quincuntial is realy playable topo. i need correct some
> >>reversed-canvas isues and a litle extention of overview. it is not so
> >>easy as a torus or a mobius(twisted torus) but kep moderatly easy after
> >>some games. And it is the best aproximation of a sphere! 
> > 
> > 
> > I played your Earth scenario with it.  I never saw the singularities. 
> > But the map was so large (with so much ocean) it was basically like an 
> > unwrapped map.  Damn the Pacific is big!
> > 
> > jason
> 
Nice, you see the doc! ;-)
there are a ticket for quincuntial(6721)!
there are a some graphics(in color) in this tickets too:
http://rt.freeciv.org/Ticket/Attachment/39952/27550/world_rec_A.xpm
and
http://rt.freeciv.org/Ticket/Attachment/39952/27551/WorldPierce100_x4.xpm
> Here is an attempt to present a comprehensive view of the qunincuntial
> map rather than trying to figure out from small GUI windows just what
> all the relationships are. One can pan a virtual GUI window over the
> projection to see what things are really like. There is a little bit
> of analysis below that shows Marcelo has some work cut out to make a
> case, or needs to come up with some fixes to resolve the problems.
> 
> 
> The attachment is a four-fold quincuncial map that can be simply tiled
> in both cartesian axes since all complex wrappings are now folded in.
> 
> One advantage of laying out such a map is that it includes all the
> complex edge joins leaving one with a simple 2-D map over which a
> GUI window can float to give the picture seen by a player of the
> game. Because all tiling is simple, it corresponds to the smallest
> torus world which can be constructed as an alternate implementation.
> Note simple tiling is what torus-worlds are effectively designed for.
> 
> 
> The normal set for a quincunx consists of one of the four corner sets
> or a square with corners at each north pole. Note that because of the
> cutting and stretching of the southern hemisphere in the normal set,
> and reversed join between any two normal sets, normal sets are distinct
> and not representable as a square with arbitrary origin as is the
> simple case when the normal set completely overlaps the torus world
> and normalization involves only simple wrapping.
In the first xpm. you see a alternate 'normal set'
> 
> There are two classes of normal sets, one with each pole at the
> centre and the other pole quartered in the corners. Each class
> consists of non-overlapping super-tiles related by translation and
> possibly rotation. The relationship between two sets in different
> classes involves an extra translation component based on quartile
> number.
> 
> Picking the normal set which completely or best contains the locations
> in a given GUI window, and translating between map coordinates and this
> set *is* a significantly complex process especially with smaller windows
> where there may be more than one, i.e. one from each class.
> 
> 
> An observation that is immediately obvious is that, while distances
> may be stretched, movement between any two points within a normal set
> centered on either pole is relatively sane and intuitive. On the
> otherhand, when crossing from one normal set to any other within the
> same class things become a little weird.
> 
> For example, one can leave the north pole heading across Asia and the
> Indian Ocean ... and end up at India and eventually the North pole.
> As interestingly, one can leave New Guinea heading NNW ... and in a
> few tiles arrive at New Guinea. Crossing the Pacific Ocean from North
> America takes you to South America.
Yes in this zones the map is a conical one.
> 
> Because most of the oddities in the quincuntial folding are confined
> to the southern seas, and in fact there is a 20 degree rotation from
> Grenwich meridan added to avoid clippiing S. America and making the
> distortions obvious, one only sees the real effect when one looks at
> land-land relationships across such oceans. Thus while it makes a very
> compelling map projection in a single normal set, tiling quincunxes
> introduces *very* odd results.
odd, but not bad.
I make test with a litle hacked servers and the scenario befor begining
working in cvs and players like it, (players from the net, with
standards clients!!!)

> 
> More importantly, if one were to drop a GUI window sized to hold both
> endpoints, then you would see yourself leaving both source and
> destination, running through your mirror image and arriving. Besides
> the fact that this violates the rule that one can not show elements of
> the normal set multiple times, the effect is clearly more than a minor
> distortion of distance - it plays havoc with intuitive adjacency
> relationships, and will have a tremendous negative impact on game play
> map distance calculations and other core functions.
coding problems are solved exept ia like too mach make cities there. but
generator is hacked to make ocean or poles in singularities. this
problems are resolved. my coding resolve the problems of view too.

But this is the most critical point for players! some players can play
with, others not.

> 
> There are a number of issues arising here from how to tile normal sets
> to avoid non-intuitive game effects through how to map tiles to standard
> rectangular GUI windows in a way that preserves intuitive 2-D mapviews.
> When you look at the broader picture, and start to see how non-simple
> edge sewing can make things decideedly non-intuitive, then it is clear
> that one wants to investigate just what such effects are, which sewing
> ops cause which ones, and how one needs to adjust GUI displays to make
> such anomalies recognizable at a minimum.
this singularities are in midles of edges. if overview is fixed as it is
in a flat map. we see easy where are the anomalies. 
I choice the Quincuntial_SQ for this.in the Quincuntial on a rectangle
(simplest wrap-x reversed wrap-y) there is dificult to find
singularities. 
> 
> Anything less will only hurt game play rather than provide innovative
> maps that enhance 2-D representations of valid gaming worlds.
some player like it, others not! this is a fondamental problem of
spheres in a flat world.

This is a new gameplay over the poles completly broken in classic maps.
Poles of classic make are BAD!. this is one very nice point of
quincuntial. i am a big nmbers of ideas abount enancing poles gameplay.

One idea, nuclear war over the pole. URSS-USA (as in real life :-S )
> 
> Cheers,
> RossW
> =====
\@_ Marcelo