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

["Marcelo Burda" <NOSPAM_mburda@xxxxxxxxx>]

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

Le mar 24/02/2004 à 04:32, rwetmore@xxxxxxxxxxxx a écrit :
> <URL: http://rt.freeciv.org/Ticket/Display.html?id=7287 >
> 
> 
> Marcelo Burda wrote:
> > <URL: http://rt.freeciv.org/Ticket/Display.html?id=7287 >
> > 
> > Le lun 23/02/2004 à 17:37, rwetmore@xxxxxxxxxxxx a écrit :
> > 
> >><URL: http://rt.freeciv.org/Ticket/Display.html?id=7287 >
> >>
> >>
> >>Just for amusement's sake, here is a recipe to make a map of real Earth
> >>in a torus. The projection to the 2-D torus-world surface is thus an
> >>easy second step.
> >>
.....
> > You make a nice map-art but in you torus you create N europa! N america
> > etc. etc.
> > in a sphere there are One Europa, etc, etc.
> 
> Please, Marcelo do not make silly statements like this.
> 
> If one tiles a map to make it an infinite surface, there are an infinite
> number of normal sets in the resulting 2-D plane....
But a infinite surface is not equals to a sphere!!!
this is concept about i was speaking.

>                                               .....  How many one chooses to
> take as a base tile for understanding the mechanics really doen't matter.
> Certainly to explain tiling, more than one is needed. What is needed now
> is understanding of the mechanics of your map topology and specifically
> the game playing mechanics since one is coding a game.
> 
> If you want to call the above a half-torus map so it contains only one normal
> set that is fine. The wrapping at the half torus edges is one of the more
> complex ones and there are at least two different half donut normal sets that
> one can start from. It takes two of these to form a super tile with simple
> wrapping or tiling properties. But this does not alter the 2-D projection or
> its appearance as one scrolls a GUI window over it.
> 
> [...]
> > This is wrong to thinck you can assimilate 4-Quincutial map to One torus
> > and say that is equals. in 4-Quincuntial map you See 4 time all units!! 
> 
> No, again. Stop thinking about some mathematical point that no one cares
> about and start thinking about what the 11-year old sees as the 2-D
> surface, I know this can be hard :-).

Sorry i was working with childrens from 6 y to 25 y at ULB. personly i
see perssone > 18y thincs persones <18 are a litle stupid. that is not
rigth.
i am learned complex physics concepts to normal childrens of 8y in
Bruxels! Never under-estimate childrens! 

Whe you use bad math in your code this not work then you are forced to
use the right math.
if you use bad math concept in map making you go to some result.
> What the GUI window displays depends on how big you make it. If you expand
> it to cover a 3x3 sized map area you will see 9 maps. The big question is
> whether Freeciv allows you to actually see all 9, or masks out all but a
> given normal set. The latter is the current rule, so a big GUI window would
> be mostly black tiles. But all this is client implementation stuff, and has
> nothing to do with the basic model and logic one is trying to make
> understandable.
this is a problem of clossed surface. you no speak about a infinite
surface but about a clossed one. in a clossed one we see it as a
periodic shape. this is a math mirage! this is a finite but clossed
space!!!!!!!!!
this is not equal to a infinite space.
> 
> The point of unrolling the wrapping to use 4 quincunxes so the super-tile
> has simple wrapping at its edges, is just a trivial transformation to help
> people see what the tiled 2-D surface really looks like, rather than trying to
> do complex wrapping in their heads, or put it all together by looking through
> a limited GUI window. It is the same as unrolling two earths into a torus
> mapping.
Yes this can help to undestand the quincuntial. but not to subtitue
quincuntial by torus.

> 
> Perhaps you need to stop thinking torus-world and just think simple tiling
> when you consider the infinite 2-D map display, so your knee jerk problems
> with torus and sphere associations don't keep getting in the way when
> considering the projected 2-D surface properties.
> 
> [...]
> > Quincuntial is A clossed 2D space and there are a 1-1 point
> > projection(and conformal) exept for 4 points. this is the best way to
> > project the sphere in a FLATE 2D if you like a clossed 2D space.
> 
> It makes a reasonable single map, but not tilable one. The singularities
> completly muck up the adjacencies across normal set boundaries. Like ratios
> you need to put yourself in a normal person's shoes and not those of some
> advanced mathetician and consider what they are seeing.

i undestand you but i thincks we need not under-estimate all players.
quincuntial is no so easy but is a alternate no-so-difficult. if we
organise a contest in the meta server with quincuntial and no
quincuntial maps to become the "Master of Earth"(some combined ranking
in 2 maps) i am sure a big number of player go undestand this. i am make
it some times and this work fine the most important problem was my
server was no rankings and my first scenario is a litle too big. The
clients was standar 1.14 ones, with not reverse canvas and my server was
a hacked 1.14 server.
After this nice result i begin the hard work to really make good servers
and client, with good generators. But the singularities are there and we
need life with its. 
> 
> The fact that you admit you cannot make cities near the singularities is
> just one indication of the underlying technical snafus and adjacency problems
> that make it unplayable, and a likely minefield of future maintenance errors.
> 
yes there are singularities, yes that is right. But in a classic topo
all N edge and all S edge is singular. this is easy but is very bad.
this edge is no closed!! and a real sphere is a closed surface. you
thinck it is normal. but normal is not good. normal is only normal.
torus are clossed but this is not a sphere-like topo, torus is a 1-Toru
topo not a 0-Torus topo.
sorry but 0 != 1. ask a 11 childrens if hi like play tenis with a donuts
and you go see the children differentiate a 0-Torus from a 1-Torus.

> > Why quincuntial as 4 singularitie? The sphere surface are not Flat, and
> > the Quincuntials surface are flat. This is compensated in the 4
> > singularities.
> 
> Right. And a torus stretches the point at the poles into a line. When
> flattening it, you do simple stretching of the latitudinal lines. No
> singularities, just different stretches as compensation.
Arg... but this broken good maping. in good maping we can assept some
local singularities in some point only. your proposal is simplest not
good one. exept is you make a mirror-offset topo. this way you make 2
Earth maps in a torus not only one!!. that is wrong too. that is not a
torus from the point of view of a unit.
(a mirror wraps is the some as a no wrap(then is legal) exept if it is
combined with a offset wrap, this alow to make Earth maps with out
singularyties, but there are nor really the best topologie)

you need mirror-offset wrap in N-S and simplet Wrap E-W

ghaf-...
cdab-cdan
|||| |||| 
ABCD-abcd-
EFGH-efgh-
IKJL-ikjl-

this make near classic maps and clossed surface. but poles are completly
crazy!!! with this fake-torus-sphere. we can go from usa-to-URSS via N
pole but we can not go from Europa to URSS. (yes  i know! URSS is no
more)
this is not more a point of distortion but a point of topologie. that is
not a sphere!
  
> 
> The distortions are different in each case. But for a tilable 2-D surface
> the torus mapping is clearly far superior to your current quincunx model.
> And since most wall maps are displayed using the same flattening model,
> this means that map mechanics are intuitively understood by game players.
> 
> 
> Until some of the problems with tiling quincunxes are worked out, I'm
> afraid it doesn't quite measure up. I'd still like to see you spend some
> effort trying to resolve the problems rather than trying to argue they do
> not exist. But then, maybe the quincunx model is inherently broken and
> unsuitable for game play. I haven't come to the conclusion there is no
> solution yet though.
i make all is posible to resolve the problems. but this problems is like
the dead-problems of life.
dead is unsuitable for life play. but i can not solve this problem.

Quincuntial is the best sphere like topo. but this topo has concetrate
the sphere curbature in 4 points. a can't solve this.

assept quincuntial is a nice topo is like assept life is nice. we can't
life all the time afraid about dead. we can't stop make a nice topo
beacause litles singularities.
> 
> Part of coming to that solution is to understand how many sewing operations
> cause the same headaches as qunicunxes, and if there are really only one or
> two that are worth building into Extended Topologies. Are these problems
> inherent to anything with a singularity? Are there no fixes or workarounds?
I work in make i client side to  make easy to undestand singularities. 
In generated maps 2 of 4 singularities can be placed in poles some
times, or palced in oceans this is the best solution possible.
> 
> > Best regards
> 
> 
> Cheers,
> RossW
> =====
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 . /  .     '    ,    .      (*)   '        `     '      `    .    
  |    ,  |   `     ,     .      ,   '  Marcelo Julián Burda      .
 /  '     \     `     \@_     '      .        '      `        '    
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