; LoadGLTFScene Example
; ---------------------
; Requires Extended mode.

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

camera=CreateCamera()
PositionEntity camera,0,1.5,-6

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

; A pivot to hang the imported scene on, so we can scale and spin it as one
holder=CreatePivot()

; The whole file arrives as one entity tree, parented to our pivot
scene=LoadGLTFScene("../../../samples/glTF/assets/ToyCar/ToyCar.glb",holder)
If scene=0 Then RuntimeError "Could not load ToyCar.glb: "+ModelLoadError()

; The car is authored at real-world scale, about 20cm long
ScaleEntity holder,30,30,30

; Every node of the file became a child entity you can address by yourself
parts=CountChildren(scene)
pick=1

While Not KeyDown(1)

    TurnEntity holder,0,0.4,0

    ; Space steps through the parts the file was built from
    If KeyHit(57) And parts>0
        ; Put the old selection back to full opacity
        old=GetChild(scene,pick)
        If EntityClass(old)="Mesh" Then EntityAlpha old,1
        pick=pick+1
        If pick>parts Then pick=1
    EndIf

    ; Describe whichever part is selected, and fade it so you can spot it
    part=GetChild(scene,pick)
    name$=EntityName$(part)
    cls$=EntityClass(part)
    surfs=0
    If cls$="Mesh"
        surfs=CountSurfaces(part)
        EntityAlpha part,0.3
    EndIf

    ; 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,"Space: step through the imported parts   Arrows: camera   Esc: exit"
    Text 0,20,"LoadGLTFScene(...,holder) gave one root entity with "+parts+" children"
    Text 0,40,"Part "+pick+" of "+parts+": "+Chr$(34)+name$+Chr$(34)+"   class "+cls$+"   surfaces "+surfs
    Text 0,60,"The faded part is the selected one. Helper nodes carry no geometry at all"

    Flip

Wend

End