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

["Marcelo Burda" <NOSPAM_mburda@xxxxxxxxx>]

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

Le jeu 26/02/2004 à 16:44, rwetmore@xxxxxxxxxxxx a écrit :
> <URL: http://rt.freeciv.org/Ticket/Display.html?id=7287 >
> 

> <ASIDE>
> Note, such things are not unusual on 3-D surfaces, afterall that is what a
> great circle does. But these are not the properties of 2-D maps. In a 2-D
> map Newtonian physics applies - one continues in a straight direction unless
> acted on by some external force, and there are no magic portals that cause
> you to invert your motion like light in a miror. Freeciv maps are 2-D and
> thus the above weirdness is a fatal violation of the map mechanics and core
> game rules/code. No patch should be checked in that doesn't fix this in some
> way.
> </ASIDE>
> 
Freeciv is not a phisic simulator, we need it more as a math problems. 
in the game we see a 2D map but this 2map can eventually live in a more
complex space. we never see this space but only the oddyes. this is not
a fondamental problem; this exist for man on Earth(living in a sphere).
but in space too (black holes are the most know of the public but in the
solar sistem we can find some litles oddyes of the not so flat space)
> 
> So how does one fix these problems?
> 
> 
> At a minimum, if you break 2-D map mecahnics, there must be some indication of
> points where 2-D map mechanics are being broken. This could be different 
> coloured
> sea tiles coupled with some corrective map mechanics and/or a user message.
> 
> As an example, every time one crosses the border between northern and southern
> tile domains, one could have the canvas view rotate 90 degrees and a message
> say something like "nasty gales cause course disorientation". In the range of
> any south pole the prime meridian runs EW, while in the northern region it
> runs NS. This has the interesting effect that if one keeps hitting the down
> key from India, then at some point one is actually moving at 90 degrees from
> the original motion.
> 
somethin like this exist in the quincutial patch! i make a visible line
separating the map from inversed map. (first i was make a fog in iverse
zone but the line was best) when user see the line hi undestand other
side is inverse. this is important for keyboard control of unit. we can
add a comment too. this is a nice idea to help undestand this to
players.

about tiles near conical singularities, there are a function to detect
it used in generator to force ocean there. Whe can use it to make
spetial zones  as "bermuda triangles" a partial work about it was
begining in my proposals about danger in poles but this patch was seted
to bloked. and i am wathin to this change. (this one down my Enthusiasm
too)

the patch about danger in poles not only is there to make new gameplay
in pole but to make poles a litle speatial zone where desorienting
singularities can help make a nice gameplay.

in a generated map we can make 2 poles on singularities and make 2 ozean
zones "Bermudas triangles like" this way singularities get a very
intersing role.
 

> This doesn't fix the problems of adjacent tile mechanics, i.e. core game 
> rules,
> breaking down near such singularities and the inability to build cities near
> such locations, though. That one is tough so I'll leave it for others at the
> moment. Needless to say, the broken mechanics causes a lot of such problems 
> that
> have not completely come to light yet, but will need to be identidfied and 
> fixed.
> 
> The simplest fix may actually define "black tiles" as tiles which can never be
> entered, and leave the original star holes in the map. Note this actually 
> works
> for a number of topologies, and filter ruless that introduce and handle black 
> tiles
> within normal sets as opposed to at borders, are a topo TODO. It does not
> require any other changes to map mechanics per se, since unreal tiles are 
> already
> excluded from such processing. Cities near star holes have fewer tiles, just
> like ones in flatearth maps. The unreal tiles and need to move around them is
> maybe sufficient to indicate 2-D mechanics are strange near the singularities.
> 
I thinc make nice gameplay there is best than forbide to enter. we need
to forbide make cities! yes but nobody think make a city in the pole or
bermudas triangles. if gameplay is nice, this alow player to undestand
the topological problems if you forbide it the problems is darked and
player undestand slowlly.

The danger consept is interesting to limit the usage of this zones
witout forbide its. 
> 
> There are some other minor tweaks that could be done to make a few things more
> like reality. If you look at the attached bitmap, New Zealand is halfway 
> across
> the Pacific from Australia, and has been remarked, the Pacific is huge.
> 
> One should offset the cuts 5-10 degrees more to the east, pushing S. America
> a little more into the Pacific and bringing New Zealand back into Australia's
> corner. One could even stretch everything a little bit to shrink the Pacific
> half of the map while expanding outwards from Africa in both directions.
> 
this Pierce-Projection is a Conformal, (equal-angles) not a equal-areas
Projection, then the size of the pacific is not exact these. But there
no exist (i no know) a equal-area-Quincuntial Projection. this is a fine
mathematician work (one day i go make a Burda-Quincutial projection, i
can dream! ;-)) .
Based on Pierce's map we can make a art-Earth more nice to be played.
exact Maps-Projection is not needed there.
> Because of the warping of the Southern hemisphere and the general E-W 
> expansion
> of landmasses as one moves further from any pole, S. America is bigger than
> N. America, Africa as big as Europe and Asia combined. This can be changed by
> scaling the latitude lines so they are 10% or whatever further apart at the 
> poles
> than near the equator or into the Southern Hemisphere to compensate for the
> increase in E-W dimensions of a flat circle over a spherical surface as one 
> moves
> outwards.
> 
yes size need to be changed but be carrefully Europa is a big continent
in classic maps but this is a distortion of classic maps!!!. Africa is
realy  big and asia is realy litle. See a Equal-Areas Maps!!!
attached. a good point of quincutial is there is a conformal not so far
to a equal areas Map. (this is some i realy like)

i am sorry for you but south america IS biger than north
 America. ;-)

this like odd, but this is more near to real Earth!
> 
> These sort of tweaks also bring up another point. The Quincunx map is really
> only designed for viewing Earth. There are no map generators that build maps
> with nice oceans every quarter circumference in which to hide singularities.
> 
? Sorry, as you tested my patch, generator make it! this place poles in
alternated place. some times in singularities some times not and all no
polar singularities are in oceans. (All generatod was patched)

I undestand why you think i make a bad patch. you never test it
completly!
> How many of t

> hese tweaks and hacks are generalizable in ways to automatically
> map an arbitrary map to a quincunx model? And thus is the work to do this
> part of an extended generalized topology, or just a one-off hack. Some ideas
> and discussion about how one might build an arbitrary quincunx map and what
> sorts of problems one runs into in generating it also needs to be part of the
> preliminary prototype before the patch is ready for CVS consideration.

that is donned!

> 
> Some of the questions to be asked are whether one wants to spend a lot of
> effort to only get a one-off Earth scenario with some unusual features, or do
> something else that gives a spherical representation in a general fashion with
> different distortions but none of the oddities or restrictions in the case of
> general random maps.

> Anyway, some more issues and ideas for further thought and discussion.
> 
> Enjoy!
;-) you too!
-- 
 . /  .     '    ,    .      (*)   '        `     '      `    .    
  |    ,  |   `     ,     .      ,   '  Marcelo Julián Burda      .
 /  '     \     `     \@_     '      .        '      `        '    
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~