; VectorPitch Example
; -------------------

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

camera=CreateCamera()
PositionEntity camera,0,4,-14
RotateEntity camera,8,0,0

light=CreateLight()
RotateEntity light,45,45,0

ground=CreatePlane()
EntityTexture ground,LoadTexture("media/MossyGround.BMP")

; A turret that has to tilt as well as turn
turret=CreateCube()
PositionEntity turret,0,1,0
barrel=CreateCylinder(12,True,turret)
ScaleEntity barrel,0.3,1.2,0.3
RotateEntity barrel,90,0,0
PositionEntity barrel,0,0,1.2

; The drone it is tracking, sweeping past and bobbing
drone=CreateSphere(12)
ScaleEntity drone,0.5,0.5,0.5
EntityColor drone,240,120,60

height#=4.0

While Not KeyDown(1)

    ; [ and ] fly the drone lower and higher
    If KeyDown(26) And height>-1 Then height=height-0.05
    If KeyDown(27) And height<8 Then height=height+0.05

    ; Sweep the drone left and right so the aim keeps changing
    PositionEntity drone,Sin(MilliSecs()/25.0)*7,height,7

    ; The direction from the turret to the drone (both sit at the top level,
    ; so their local coordinates are already world coordinates)
    dx#=EntityX(drone)-EntityX(turret)
    dy#=EntityY(drone)-EntityY(turret)
    dz#=EntityZ(drone)-EntityZ(turret)

    ; VectorPitch is the up/down half of the aim, VectorYaw the left/right half
    pitch#=VectorPitch(dx,dy,dz)
    RotateEntity turret,pitch,VectorYaw(dx,dy,dz),0

    ; 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

    RenderWorld

    Text 0,0,"[ / ]: fly the drone up and down   Arrows: camera   Esc: exit"
    Text 0,20,"VectorPitch("+dx+","+dy+","+dz+") = "+pitch
    Text 0,40,"RotateEntity turret,pitch,yaw,0 aims the barrel in one go"
    Text 0,60,"Up is NEGATIVE pitch: VectorPitch(0,1,0) = "+VectorPitch(0,1,0)

    Flip

Wend

End