; ParticleSpace Example
; ---------------------
; Requires Extended mode.

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

camera=CreateCamera()
PositionEntity camera,0,3,-8
CameraClsColor camera,8,12,24

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

; A patrol drone that circles the scene trailing exhaust
drone=CreateSphere()
ScaleEntity drone,0.25,0.25,0.25
EntityColor drone,255,120,60

; Exhaust emitter parented to the drone so it travels along
emitter=CreateParticleEmitter(800,drone)
ParticleEmissionRate emitter,150
ParticleLifetime emitter,1.5,2.5
ParticleVelocity emitter,0,0.5,0,0.2,0.2,0.2
ParticleColor emitter,255,180,80,1,120,120,130,0
ParticleSize emitter,0.12,0.3,0.2
EntityBlend emitter,3

; World space: the trail stays behind where it was emitted
ParticleSpace emitter,True
world_space=True

angle#=0

While Not KeyDown(1)

    ; Space toggles world-space and local-space particles
    If KeyHit(57)
        world_space=Not world_space
        ; Changing space clears the live particles
        ParticleSpace emitter,world_space
    EndIf

    ; Fly the drone in a circle
    angle=angle+1.5
    PositionEntity drone,Cos(angle)*2.5,2,Sin(angle)*2.5

    ; 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   Space: toggle particle space   Esc: exit"
    If world_space Then state$="True (trail is left behind)" Else state$="False (cloud follows the drone)"
    Text 0,20,"ParticleSpace emitter,"+state$

    Flip

Wend

End