Implement minimap

[franciscod]

Should we limit the world terrain size for this? What if the world grows? The minimap scale changes accordingly to accomodate the whole world?

attached screenshot for reference

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[lilezek]

Scaling minimap wouldn't be a nice feature in my opinion. I can think about two alternatives:
· To center the minimap to the region you are.
· To make the minimap able to zoom.

[franciscod]

In the game, the world has a defined size so it calculates the minimap scale on initialization. In our demo, the world can grow indefinitely. That's the main difference.

Should we fix the world to some size?

[hackathi]

It's against intentions to cut anything at any given arbitrary limit (at least in the engine - I actually think that fixed size maps have to be supported, but that does not affect the possibility to have an endless map). I'd go with a scrolling minimap, that shows reasonable sourrounding or the whole map if it is small enough.

[mic-e]

Fixed-size maps would obviously be supported, and the default mode for regular games, but maps with mincraft-like infinite terrain generation, or cylindrical/toroidal maps would also be incredibly cool...

I think for now we should just go with a minimap that scales down each time the map has grown (maybe in powers of two).

Monoterrain means we're able to draw just one single type of terrain. We're far beyond that at this point, but the building placement still doesn't work perfectly (think town center), so the milestone isn't finished yet.

[goto-bus-stop]

I think scaling it provides the most flexibility in standard, non-infinite-map games, as you can then have any predefined map size, and have the minimap fill its entire box.

Minimaps on infinite maps are a bit weird, you're almost definitely going to center it on your current viewport location, but at some predefined size or zoomable?

Maybe initially we can just have it scale, and not render non-generated chunks (& unexplored territory), and add something for infinite maps later?

Is anyone working on this at the moment? If not I would like to work on it.

[franciscod]

go on @jgelderloos !

[jfeo]

Are you still working on this @jgelderloos ? I've quickly put something together... judging by the temperature of my cpu when I run it, it's preeeeetty inefficient, but I could probably improve that ;-)

No units yet, and terrain colors are hardcoded to the terrain_id of the tile, and many other issues, but it looks alright at least :D

@jfeo , no not at the moment. I had a start on it but got distracted and have not worked on in a quite a while. What you have looks good. A few things to think about: The minimap probably does not need to update that often, maybe only once a second or so. Also, you may not want/need as much detail in it as you have. Especially if you want to support the goal of having very large maps you will need a way to compress the terrain data. So if there is a tiny lake in a large map, maybe it does not show up in the map. Anyways, good luck with it. Le me know if you make a PR of this and I will take a look at it.

[jfeo]

My idea for the minimap would be to make several layers, for terrain, units (and different kinds, such as military, civil, trade?). Mapping from minimap coordinates to real game coordinates (which is sort of needed anyway to make it at all).

A lot of the minimap computations happen each frame for now. Ideally at least the unit layer (when it is implemented) should update every frame, I think, as it will look weird otherwise. For the terrain, it would probably be better to only do an initial texture and then update it when the terrain changes (Some buildings change the terrain underneath them).

I haven't found any functionality yet that can trigger a minimap update when the terrain changes. Does anything like that exist?

Also the issues of how to choose a colour for each terrain_id... Initially I suppose it is okay to hard code, but it would be nice with a better solution - perhaps based on the terrain texture images themselves.

[fricklerhandwerk]

@jfeo On minimap terrain color: You could pre-compute an average color from each tile at compile time and save that somewhere in a file.

[mic-e]

@frickler01 you could, and it's a good idea (but it would happen at convert time), but then it wouldn't look like the original game...

[jfeo]

I thought about that. It would be nice, as it kind of suits the idea avoiding false limitations, and would enable additions to the tileset without messing up the minimap. Another idea would be to keep the terrain_id color mapping as some kind of metadata, although if it is not kept in the original game files it might end up a bit hacky, and I haven't been able to find it.