Create ingame map / prefab editor

[rm-code]

After playing around with tons of different editors and file formats I think the best way to add new map content to the game is to write an ingame editor.

• First of all there would be no need for any conversion between external formats and the ones used by OTR (plus any mapping to actual content).
• With a custom map editor we can directly load all tile and worldobject templates we have in the game and use them to create new content.
• We can also easily add special information (like road alignment Rotate prefabs so they face nearby roads #186)
• It would also be easily accessible by players and modders later on

TODOs

• Screen with grid and camera
• Draw Mode
• Fill Mode
• Erase Mode
• Different cursor sizes
• Different canvas sizes
• Hide object layer on keypress
• Highlight layer if type is selected (make other translucent?)
• Tab between select lists
• Layout grid resizable
• Show cursor mode, selected brush, brush size, grid size on UI
• Custom names
• File loading screen ... scrollable

TODOs Refactor

• PrefabCanvas

FIXME

• EditorLoadingScreen has still normal input

[rm-code]

Layout files

layout = {
    id = 'layout'
    mapwidth  = 6,
    mapheight = 6,
    prefabs = {
        XS = {
            {
                x = 8,
                y = 2
            },
            {
                x = 3,
                y = 6
            }
        },
        S = {
            -- ...
        }
        -- ...
    }
}

Prefab files

prefab = {
    id = "test",
    size = "XS",
    height = 8,
    width = 8
    grid = {
        {
            worldObject = "worldobject_lowwall"
            tile = "tile_soil"
        },
        -- ...
    }
}