[solved] OpenGL: Could not find FB config.
lazarus / 70-OpenGL

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Ocye · 2012-06-12 16:20

I use LazOpenGLContext successfully for some time. But after one of
the recent LCL updates, I get the mentioned error when the context
becomes visible. The example runs perfectly. However, I don't do any
advanced stuff. Just standard Gl and Glu. Any idea where to look for
the problem?

Lazarus 1.1 r37618 FPC 2.6.0 x86_64-linux-qt (compile target is gtk2)
Linux version 3.3.8-1-ARCH (tobias@T-POWA-LX) (gcc version 4.7.0
20120505 (prerelease) (GCC) ) #1 SMP PREEMPT Tue Jun 5 15:20:32 CEST
2012

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Ocye · 2012-06-16 12:49

It works if I replace changes in gdk_gl_context_share_new() with rev
37115. Is attrList[] really assigned to valid data?

Code: [Select]{$IFDEF UseFPGLX}
  FBConfig: TGLXFBConfig;
  FBConfigs: PGLXFBConfig;
  FBConfigsCount: Integer;

  { Attributes to choose context with glXChooseFBConfig.
    Similar to Attr, but not exactly compatible. }
  AttrFB: Array[0..10] of integer = (
            GLX_X_RENDERABLE, 1 { true },
            GLX_RED_SIZE, 1,
            GLX_GREEN_SIZE, 1,
            GLX_BLUE_SIZE, 1,
            GLX_DOUBLEBUFFER, 1 { true },
            none);
{$ENDIF}
...
FBConfigs:=glXChooseFBConfig(dpy, DefaultScreen(dpy), AttrFB,
FBConfigsCount);

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zamtmn · 2012-06-25 14:24

Hi.
Perhaps this patch solves the problem?

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Ocye · 2012-06-25 15:54

No, FBConfigsCount is still 0 (rev 37777 with patch).

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zamtmn · 2012-08-21 20:41

I also get this error when dynamically creating OpenGLContext in
OnCreate form handler. If moved it to OnShow all starts working

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User137 · 2012-08-22 23:03

My little game engine nxPascal has like forever now created
LazOpenGLContext dynamically at FormCreate, but i use win32.

Is this gtk related, or are you creating it with nil owner?

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Ocye · 2012-08-22 23:24

Quote from: User137 on August 23, 2012, 01:03:09 amIs this gtk
related, or are you creating it with nil owner?
function gdk_gl_context_share_new() is defined in GLGtkGlxContext
which is switched on/off in OpenGLContext
Code: [Select]{$IFDEF UseGtk2GLX}
  GLGtkGlxContext;
{$ENDIF}
{$IFDEF UseCarbonAGL}
  GLCarbonAGLContext;
{$ENDIF}
{$IFDEF UseWin32WGL}
  GLWin32WGLContext;
{$ENDIF}

As far as I remember it was/is a Gtk2 issue only.

The Gl context is created dynamically.
Code: [Select]TScrabbleCube=class(TOpenGLControl)
public
  constructor Create(aOwner:TComponent);override;
end;

constructor TScrabbleCube.Create(aOwner: TComponent);
begin
  inherited Create(aOwner);
  Parent:=aOwner as TWinControl;
...

TMain.OnSomething()
  ScrabbleCube:=TScrabbleCube.Create(pn3D);

The code runs well with my patch.

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zamtmn · 2012-09-13 03:48

http://bugs.freepascal.org/view.php?id=22868

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zamtmn · 2012-09-18 07:33

Ocye
it work after rev38678?

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Ocye · 2012-09-27 10:21

Yes, it works perfectly.
(tested with revision 38851)