; CountParticles Example
; ----------------------
; Requires Extended mode.

Graphics3D 640,480,0,2
SetBuffer BackBuffer()

camera=CreateCamera()
PositionEntity camera,0,2,-6
CameraClsColor camera,8,12,24

floor=CreatePlane()
EntityColor floor,30,34,44

; A fiery fountain in the middle of the scene
emitter=CreateParticleEmitter(1000)
PositionEntity emitter,0,0.5,0
ParticleLifetime emitter,1.5,2.5
ParticleVelocity emitter,0,4,0,0.6,0.5,0.6
ParticleGravity emitter,0,-4,0
ParticleColor emitter,255,220,120,1,255,80,0,0
ParticleSize emitter,0.12,0.03,0.2
EntityBlend emitter,3

rate=100

While Not KeyDown(1)

    ; [ / ] change the emission rate, Space fires a burst
    If KeyDown(26) And rate>0 Then rate=rate-2
    If KeyDown(27) And rate<400 Then rate=rate+2
    ParticleEmissionRate emitter,rate
    If KeyHit(57) Then EmitParticles emitter,200

    ; Arrow keys move the camera
    If KeyDown(200) Then MoveEntity camera,0,0,0.1
    If KeyDown(208) Then MoveEntity camera,0,0,-0.1
    If KeyDown(203) Then TurnEntity camera,0,1,0
    If KeyDown(205) Then TurnEntity camera,0,-1,0

    ; UpdateWorld also advances the particle simulation
    UpdateWorld
    RenderWorld

    Text 0,0,"Arrow keys: move camera   [ / ] : emission rate   Space: burst   Esc: exit"
    ; CountParticles reports how many particles are alive right now
    Text 0,20,"CountParticles(emitter) = "+CountParticles(emitter)
    Text 0,40,"Emission rate: "+rate+" per second"

    Flip

Wend

End