Round Earth in Openttd

[agentw4b]

Do somebody repair a game for a round Earth please

Just the train when it arrives at the edge of the map, appears on the other side.

[Gwyd]

This is a very interesting concept, but I think it'd be more useful if you could go between/link maps

[Transportman]

This is a very interesting concept, but I think it'd be more useful if you could go between/link maps

You could play on a bigger map and have the same result. Linking maps while keeping them separate is not possible, as calculations would still need to be done for both maps (although drawing and stuff is not needed for one of them).

I do recall that there is a patch or NewGRF that would create industries at the map edge where you could drop all cargoes and get all cargoes back, mimicking such a link.

[kamnet]

Design your maps or scenarios using polar projection?

[agentw4b]

Design your maps or scenarios using polar projection?

Earth is Flat ?

[Drury]

Design your maps or scenarios using polar projection?

Earth is Flat ?

Yes !

[agentw4b]

Design your maps or scenarios using polar projection?

Earth is Flat ?

Yes !

I made it .
viewtopic.php?f=60&t=82397

[Redirect Left]

Just the train when it arrives at the edge of the map, appears on the other side.

That'd be an interesting way to play. Certainly should be possible (with a lot of editing / patching). Although you'd need to make sure you had tracks setup at the other side of the map. It'd be hard to make sure you have properly aligned tracks at the other side of the map.

[Leanden]

Getting track/roads to match either side would be the simple part.

Rewriting the pathfinder to crossover the map edges to the other side would be the challenge

[Redirect Left]

Rewriting the pathfinder to crossover the map edges to the other side would be the challenge

Hmm. Would probably require a pathfinder specifically wrote for this purpose, clone another one then edit it to your needs. Not sure it'd work with a normal 'earth' in openTTD after modification, with any sort of efficiency.

[Gwyd]

What if the map actually wrapped around, so at the left, the right would start again. This would mean old pathfinders work... Maybe. This is why I dont do patches.

[Redirect Left]

What if the map actually wrapped around, so at the left, the right would start again. This would mean old pathfinders work... Maybe. This is why I dont do patches.

I suspect that'd be more patching than just making the train appear at the other side, more graphic stuff in my experience takes more work.

[Drury]

What if the map actually wrapped around, so at the left, the right would start again. This would mean old pathfinders work... Maybe. This is why I dont do patches.

When you see this done in a game (like in Civilization games), what they actually do is just have a regular rectangular map and teleport things from one side to the other at the edges (which is the original suggestion anyways), it's just made to look seamless by rendering the edge bits from the other side when needed. There isn't really a magical way to have looping maps without this workaround.

[agentw4b]

Round Earth should, of course, only be one of the choices. If you can do this, it will be great.

[raidho36]

Rewriting the pathfinder to crossover the map edges to the other side would be the challenge

Hmm. Would probably require a pathfinder specifically wrote for this purpose, clone another one then edit it to your needs. Not sure it'd work with a normal 'earth' in openTTD after modification, with any sort of efficiency.

No it would literally require no modification. Pathfinder works over abstract graphs which don't care about space-time geometry, and a piece of rail going to the other side of the map over the edge is not in any way different from a piece of rail simply going from left to right in an ordinary fashion. Same logic applies to rails that loop over the edge of the map - loops are already well handled in ordinary maps.

[GiaNN]

Rewriting the pathfinder to crossover the map edges to the other side would be the challenge

This is not at all complicated, I wrote it some years ago not for OpenTTD. All you need is the access of the map (be it read or write) to be wrapped in a function. The function translates any false coordinates to correct coordinates. Then make sure all scripts always use this function and everything rolls just fine without big changes of the core code, yet the game "world" becomes infinite beyond the edges.

if you request data for position X,Y and X and/or Y is a negative value exiting the map in the top or a larger than the map size number exiting in the bottom, than add or subtract the value from map size until a valid positive value is the result. depending on if the map is using 0,0 as first coordinate, or 1,1 doesn't matter for the concept. So for explaining and understanding, I now assume the first tile is identified as [1,1], in programming this more likely will be position 0,0.

hence, in the case we are using a map size 1024x1024:

requesting coordinate [-20,1300] (both X and Y are outside the map range) the function simply results in returning values for [1004,276]

or requesting coordinate [500,4000] (Y is outside the map but X is not) results in returning values for [500,928]
in the last example the value 4000 is 3 times outside the world so 3 times 1024 was subtracted.

or maybe more simple to understand assuming we again have a map size of 1024x1024 tiles:

requesting the coordinate [-1,-1] should result in accessing the data for [1023,1023] and requesting ccordinate [1025,1025] will result in accessing the data of [1,1]

In this virtually visualised example (not from OpenTTD), it works the same way, the lower corner is closer to the upper corner. the left corner is closer to the right corner.


The pathfinder should now automatically find a shorter route to a location outside the map if that same location inside the map is further away.

[Eddi]

while this approach would generally work, you get two main problems here:

1. the world you produce isn't actually "round" but "toroidal"
2. the map generator is not equipped to make sure the map border is "smooth" enough to connect both sides, unless you force map edges to be water

and then you need to find all the places where it currently checks that it *doesn't* cross the map borders