--Create a window
window = Window:Create()
context = Context:Create(window)
world = World:Create()
camera = Camera:Create()
camera:Move(0,0,-3)

local rotationspeed = 90

--Create an emitter
emitter = Emitter:Create(500) 

local material = Material:Load("Materials/Effects/spark.mat") 
if (material) then
    emitter:SetMaterial(material) 
    material:Release() 
end

emitter:SetVelocity(0,0,0,0)  --set base velocity to 0
emitter:SetRotationSpeed(rotationspeed) 

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
        rotationspeed = rotationspeed + 1
        emitter:SetRotationSpeed(rotationspeed) 
    elseif window:KeyDown(Key.Down) and rotationspeed>0 then
        rotationspeed = rotationspeed - 1
        emitter:SetRotationSpeed(rotationspeed) 
    end

    context:SetBlendMode(Blend.Alpha) 
    context:DrawText("Rotation speed: " .. emitter:GetRotationSpeed() .. " degrees per second." ,2,2) 
    
    context:Sync()
end