Function createline(x1#,y1#,z1#, x2#,y2#,z2#, mesh=0)
   
   If mesh = 0 Then
      mesh=CreateMesh()
      EntityFX(mesh,16)
      surf=CreateSurface(mesh)   
      verts = 0   
   
      AddVertex surf,x1#,y1#,z1#,0,0
   Else
      surf = GetSurface(mesh,1)
      verts = CountVertices(surf)-1
   End If
   
   AddVertex surf,(x1#+x2#)/2,(y1#+y2#)/2,(z1#+z2#)/2,0,0
   ; you could skip creating the above vertex and change the line below to
   ; AddTriangle surf,verts,verts+1,verts+0
   ; so your line mesh would use less vertices, the drawback is that some videocards (like the matrox g400)
   ; aren't able to create a triangle with 2 vertices. so, it's your call :)
   AddVertex surf,x2#,y2#,z2#,1,0
   
   AddTriangle surf,verts,verts+2,verts+1
   
   Return mesh
End Function

; --- set graphics
Graphics3D 640,480,32,0
SetBuffer(BackBuffer())

; --- create scene setup
camPiv = CreatePivot()
camera = CreateCamera(camPiv)
PositionEntity(camera, 0,0,-10)

light=CreateLight(2)
PositionEntity(light,4,10,0)
LightRange(light,10)

; --- create test cube
cube=CreateCube()
ScaleMesh(cube, 2,1,1)
EntityAlpha(cube, 0.5)
cube2=CreateCube()
ScaleMesh(cube2, 1.8,0.8,0.8)

; --- create lines
lines = createLine(2,1,1,    1,2,1)
lines = createLine(1,2,1,    0,2.3,1, lines)
lines = createLine(0,2.3,1, -1,2,1, lines)
lines = createLine(-1,2,1,  -2,1,1, lines)
EntityColor(lines, 255,0,0)

; okay, this is a bit cheating and very wrong/memory leak prone and shouldn't be used this way
; but i wanted to show more than one Line quickly

lines = createLine(2,1,-1,    1,2,-1)
lines = createLine(1,2,-1,    0,2.3,-1, lines)
lines = createLine(0,2.3,-1, -1,2,-1, lines)
lines = createLine(-1,2,-1,  -2,1,-1, lines)
EntityColor(lines, 255,0,0)

lines = createLine(-3,1,1,   3,1,1)
EntityColor(lines, 255,0,0)
lines = createLine(-5,1,-1,  4,1,-1)
EntityColor(lines, 255,0,0)
lines = createLine(-4,-1,1,  3,-1,1)
EntityColor(lines, 255,0,0)
lines = createLine(-3,-1,-1, 5,-1,-1)
EntityColor(lines, 255,0,0)

TurnEntity(campiv, 35,35,35)

While Not KeyHit(1)

   ; --- camera controls
   scrollwheel = MouseZSpeed()
   If MouseDown(1) Then
      TurnEntity(camPiv, MouseYSpeed(),-MouseXSpeed(),0)
   Else If scrollwheel <> 0 Then
      MoveEntity(camera, 0,0,scrollwheel*3)
   Else
      dummy = MouseYSpeed():dummy = MouseXSpeed():dummy = MouseZSpeed() ; prevent mousespeed blips.
   End If

   ; --- rendering
   CameraClsMode(camera, 1, 1)
   WireFrame(0)
   ShowEntity(cube)
   ShowEntity(cube2)   
   RenderWorld()
   
   CameraClsMode(camera, 0, 0)
   WireFrame(1)
   HideEntity(cube)
   HideEntity(cube2)   
   RenderWorld()

   ; or try this:
   ;CameraClsMode(camera, 1, 1)
   ;WireFrame(1)
   ;HideEntity(cube)
   ;HideEntity(cube2)   
   ;RenderWorld()
   
   ;CameraClsMode(camera, 0, 0)
   ;WireFrame(0)
   ;ShowEntity(cube)
   ;ShowEntity(cube2)   
   ;RenderWorld()
   Flip()
Wend

End