TBGL- multiple displays

More than one TBGL-display quite easy to achieve - but needs UI-Canvas.

Example shows how two different "scenes" can be displayed in two different canvas-controls at same time.
Not using scene/entity-system here but is doable rendering different scenes to different output also.
Even works in seperate dialogs.
If displaying same scene from different points of view then camera-entity has to be placed according to the current view.

Code:

---

Uses "UI", "TBGL"

' -- ID numbers of controls
Begin ControlID
  %lCanvas1
  %lCanvas2
 
  %bClose
 
  %myTimer
End ControlID

Begin Const
  %MAIN_WIDTH  = 640
  %MAIN_HEIGHT  = 480

  %timeOut      = 20  ' -- Determines graphics refresh rate in milliseconds
End Const

Function TBMain()

  Local hDlg As DWord

  Dialog New Pixels, 0, "Dialog with TBGL",-1,-1, %MAIN_WIDTH, %MAIN_HEIGHT, _
                                    %WS_POPUP Or %WS_VISIBLE Or _
                                    %WS_CLIPCHILDREN Or %WS_CAPTION Or _
                                    %WS_SYSMENU Or %WS_MINIMIZEBOX Or %WS_MAXIMIZEBOX, 0 To hDlg
   
    ' -- Place controls:
    Control Add Label, hDlg, %lCanvas1, "", 5, 5, %MAIN_WIDTH/2-10, %MAIN_HEIGHT-40
      Control Set Color hDlg, %lCanvas1, %BLACK, %BLACK
 
    Control Add Label, hDlg, %lCanvas2, "", %Main_Width/2+5, 5, %MAIN_WIDTH/2-10, %MAIN_HEIGHT-40
      Control Set Color hDlg, %lCanvas2, %BLACK, %BLACK
 
    Control Add Button, hDlg, %bClose, "Close", 5, %MAIN_HEIGHT-30, %MAIN_WIDTH - 10, 25
 
    Dialog Show Modal hDlg, Call dlgCallback
   
End Function 
 
CallBack Function dlgCallback()
  Static hCtrl As DWord
 
  Select Case CBMSG
   
    Case %WM_INITDIALOG
      ' just init timer
      Dialog Set Timer CBHNDL, %myTimer, %timeOut, %NULL
 
    Case %WM_TIMER
      Control Handle CBHNDL, %lCanvas1 To hCtrl
      RenderMyImage(hCtrl, %lCanvas1)

      Control Handle CBHNDL, %lCanvas2 To hCtrl
      RenderMyImage(hCtrl, %lCanvas2)

    Case %WM_CLOSE
      Control Handle CBHNDL, %lCanvas1 To hCtrl
      If TBGL_CanvasBound(hCtrl) Then TBGL_ReleaseCanvas(hCtrl)     
      Control Handle CBHNDL, %lCanvas2 To hCtrl
      If TBGL_CanvasBound(hCtrl) Then TBGL_ReleaseCanvas(hCtrl)     
 
      Dialog Kill Timer CBHNDL, %myTimer
     
    Case %WM_COMMAND
      Select Case CBCTL
       
        Case %bClose
          If CBCTLMSG = %BN_CLICKED Then Dialog End CBHNDL
       
      End Select
     
  End Select
End Function


Sub RenderMyImage( ByVal hCtrl As DWord, ByVal ID_Canvas As Long )


  TBGL_BindCanvas(hCtrl)    ' no need to update canvas-proprtions...
     
  If TBGL_CanvasBound(hCtrl) Then
   
    TBGL_UseLighting(%TRUE)
    TBGL_UseLightSource(%GL_LIGHT0, %TRUE)
    TBGL_SetLightParameter(%GL_LIGHT0, %TBGL_LIGHT_POSITION, 15, 10, 15, 1)

 
    TBGL_ClearFrame
      TBGL_Camera(5, 5, 5, 0, 0, 0) 
     
      If ID_Canvas = %lCanvas1 Then
      ' show "scene 1"
        TBGL_Box(1, 1, 1)
      Else
      ' show "scene 2"
        TBGL_Sphere(1)
      EndIf     
   
    TBGL_DrawFrame
   
  EndIf 
End Sub

---

Edit: limitation removed

I will check during the weekend whether I can work around this limitation.


Petr

Hmm,

I don't see any problem changing LOC and SIZE property, could you please post failing example?


Petr

I threw it all out and have not saved the "old" version.

Maybe I did it wrong? The effect was the canvases did not correctly resize (used CONTROL SET RESIZE) and without that switch I did not try out. Maybe this switch interfered also when I used CONTROL SET LOC.

That's also the reason why I tried to create multiple TBGL-displays at all: As long as Dialogs & Controls are not Objects with clearly defined Events, Methods and Properties they are way too cumbersome to handle and not applicable for a bigger project so I need to create own "Control-Objects"
I already was that frustrated about UI-handling that I erased all I've written - and more than once - lots of hours thinking and typing just flushed down to neverland.
Especially annoying that I can not use Dialogs nor Control-Properties directly, but always have to send them "TO" some local variable in advance with half a dozen parameters just to get some simple value out there and need always a few lines just for one simple action because the result is not returned directly.
Also these make code so unreadable - I have some idea, start to write and get stuck when it comes to UI - always have to look up and down again - my code then is such chaos that I can not read myself what I wrote and loose overview of situation and used calls so it becomes impossible to continue and I have to stop and start all over.

Hi Rene,

I think CONTROL SET RESIZE could clash a bit with CONTROL SET LOC/SIZE - it is one or another.
I agree the "TO syntax" is a bit impractical sometimes -that is why Eros added Control_GetHandle, Control_GetWidth, Control_GetHeight, Control_GetText and others... which behave like normal functions.


Petr