--Create a window
window = Window:Create()
context = Context:Create(window)
world = World:Create()
camera = Camera:Create()
camera:Move(0,0,-3)
local light = DirectionalLight:Create()
light:SetRotation(35,35,0)

--Create an emitter
emitter = Emitter:Create(100) 
local sz = 1
emitter:SetEmissionVolume(sz,sz,sz)

while true do
    if window:Closed() or window:KeyHit(Key.Escape) then return false end

    Time:Update()
    world:Update()
    world:Render()
    
    if (window:KeyDown(Key.Up)) then
        sz = sz + 0.05
        emitter:SetEmissionVolume(sz,sz,sz)
    elseif (window:KeyDown(Key.Down)) then
        sz = sz - 0.05
        sz = math.max(sz,0)
        emitter:SetEmissionVolume(sz,sz,sz)
    end
    
    context:SetBlendMode(Blend.Alpha)
    context:DrawText("Emission volume: "..emitter:GetEmissionVolume():ToString(),0,0)
    
    context:Sync()
end