; ClearEntityLODs Example
; -----------------------
; Requires Extended mode.

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

camera=CreateCamera()
PositionEntity camera,0,4,-15
CameraClsColor camera,20,30,50

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

ground=CreatePlane()
EntityColor ground,60,80,55

; Each detail level is painted its own colour so switches are easy to spot
green_brush=CreateBrush(60,200,80)
amber_brush=CreateBrush(230,180,50)
red_brush=CreateBrush(220,70,60)

; Detailed base tree, plus two cruder stand-in meshes
tree=CreateSphere(16)
ScaleMesh tree,1,2,1
PositionMesh tree,0,2,0
PaintMesh tree,green_brush

tree_mid=CreateSphere(6)
ScaleMesh tree_mid,1,2,1
PositionMesh tree_mid,0,2,0
PaintMesh tree_mid,amber_brush

tree_far=CreateCube()
ScaleMesh tree_far,0.9,1.8,0.9
PositionMesh tree_far,0,1.8,0
PaintMesh tree_far,red_brush

AddEntityLOD tree,tree_mid,10
AddEntityLOD tree,tree_far,20

; A forest of copies - CopyEntity copies the complete LOD table
Dim trees(59)
For n=0 To 59
    trees(n)=CopyEntity(tree)
    PositionEntity trees(n),(n Mod 6)*4-10,0,(n/6)*5
Next
HideEntity tree
HideEntity tree_mid
HideEntity tree_far

lods_on=True

While Not KeyDown(1)

    ; Space strips or re-registers the LOD table on every tree
    If KeyHit(57)
        lods_on=Not lods_on
        For n=0 To 59
            If lods_on
                AddEntityLOD trees(n),tree_mid,10
                AddEntityLOD trees(n),tree_far,20
            Else
                ClearEntityLODs trees(n)
            EndIf
        Next
    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,"Arrow keys: move camera   Space: toggle LODs   Esc: exit"
    If lods_on
        Text 0,20,"LODs registered: amber from 10 units, red from 20"
    Else
        Text 0,20,"ClearEntityLODs called - every tree uses its base mesh"
    EndIf
    Text 0,40,"Trees drawn with a LOD mesh: "+RenderLODSelections()

    Flip

Wend

End