Hello World

01 - Hello World and the Lifecycle

Lifecycle logger

Attach to: any Entity.

Prints when each lifecycle function runs, plus a heartbeat message every few seconds. Attach it, press play, and then try disabling the Entity or the script to watch OnDisable / OnEnable fire.

-- Scripts/Examples/HelloWorld.lua (entity script)
public string greeting = "Hello from Tilky!"

function OnEnable()
    Debug.Print("[" .. entity.name .. "] OnEnable")
end

function Start()
    Debug.Print(greeting, "- I am", entity.name, "(id " .. entity.id .. ")")
end

local heartbeat = 0.0

function Update()
    heartbeat = heartbeat + GameTime.deltaTime

    if heartbeat >= 3.0 then
        heartbeat = heartbeat - 3.0
        Debug.Print(entity.name .. " is still alive")
    end
end

function FixedUpdate()
    -- Runs at a fixed 60 Hz. Nothing to do here, it is only listed for completeness.
end

function OnDisable()
    Debug.Print("[" .. entity.name .. "] OnDisable")
end

function OnDestroy()
    Debug.Print("[" .. entity.name .. "] OnDestroy")
end

Notes

• Debug.Print(...) joins any number of arguments with spaces (like Lua's print) and shows them in the in-game console. Debug.LogInfo/LogWarning/LogError go to the engine log instead.
• Anything time-based should be multiplied by GameTime.deltaTime, otherwise it runs faster on faster machines.

---

A script on a sector

Attach to: a sector (sector inspector, Scripts section).

Sector scripts have the same lifecycle, but sector replaces entity.

-- Scripts/Examples/SectorInfo.lua (sector script)
function Start()
    local name = sector.name
    if name == "" then name = "(unnamed)" end

    Debug.Print("Sector", sector.id, name)
    Debug.Print("  floors:", sector.floorCount, " walls:", sector.wallCount,
                " vertices:", sector.vertexCount, " neighbours:", sector.neighborCount)
    Debug.Print("  floor height:", sector.floorHeight)

    for i = 1, sector.neighborCount do
        local neighbour = sector:GetNeighbor(i)
        if neighbour.isValid then
            Debug.Print("  next to sector", neighbour.id)
        end
    end
end

Notes

• sector.floorHeight is a shortcut for sector:GetFloor(1).floorHeight. Sectors can have several floor/ceiling intervals, so use GetFloor(n) for the others.
• GetNeighbor(i) can return an invalid reference, so check isValid first.