The map format is relatively simple, but the current parser is not very good and will fail with a cryptic error message on any mistakes you make.
At the minimum, a map needs a
[map] section, with a
map option in it, like this:
[map] map = .
This particular example is a single floor tile. To have more than one line of the map, you need to indent the other lines:
[map] map = ... ... ...
By default, "." is defined as a floor tile, and "X" is defined as wall. You can however define much more tiles. A tile definition looks like this:
[,] tileset = ground.png tile_x = 1 tile_y = 3
This defines the "," character to be displayed as tile (1, 3) from the tileset "ground.png". The tileset looks like this:
So from now on, whenever you put "," on the map, a piece of ground with two small plants will be drawn. Note that it will only happen on this single particular map though – the definitions are local and you have to repeat them on every map on which you wish to use them.
There are also more advanced things you can do: