; ModelLoadError Example
; ----------------------
; Requires Extended mode.

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

camera=CreateCamera()
PositionEntity camera,0,1,-6

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

; A stand-in prop that spins while no model has been loaded
placeholder=CreateSphere(12)
ScaleEntity placeholder,0.4,0.4,0.4

; Start with a deliberate failure so there is a message to read straight away
tried$="media/no_such_model.b3d"
model=LoadMesh(tried$)
; ModelLoadError reports the last loader failure, or "" after a success
why$=ModelLoadError()

While Not KeyDown(1)

    ; 1 a real model, 2 a file that is not there, 3 a file that is not a model
    want$=""
    If KeyHit(2) Then want$="media/oil-drum/oildrum.3ds"
    If KeyHit(3) Then want$="media/no_such_model.b3d"
    If KeyHit(4) Then want$="media/b3dlogo.jpg"

    If want$<>""
        If model<>0 Then FreeEntity model
        tried$=want$
        ; LoadMesh just returns 0 when it fails - it never says why
        model=LoadMesh(tried$)
        why$=ModelLoadError()
        If model<>0 Then FitMesh model,-1,0,-1,2,2,2,True
    EndIf

    ; Show the placeholder only while there is no model to look at
    If model=0
        ShowEntity placeholder
    Else
        HideEntity placeholder
    EndIf

    TurnEntity placeholder,0,1.5,0
    If model<>0 Then TurnEntity model,0,0.6,0

    ; 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,"1: real model   2: missing file   3: not a model   Arrows: camera   Esc: exit"
    Text 0,20,"LoadMesh("+Chr$(34)+tried$+Chr$(34)+") = "+model
    If why$=""
        Text 0,40,"ModelLoadError() = "+Chr$(34)+Chr$(34)+"  - empty, so that load worked"
    Else
        Text 0,40,"ModelLoadError() = "+why$
    EndIf
    Text 0,60,"Print this string when a load fails and you know exactly what broke"

    Flip

Wend

End