OpenGL Context with Anti-Aliasing but without wxGLCanvas

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LukasBanana
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Knows some wx things
Posts: 27
Joined: Mon Jul 11, 2011 5:02 pm

OpenGL Context with Anti-Aliasing but without wxGLCanvas

Post by LukasBanana »

Hi,
I'm currently working with wxWidgets 3.0.0 and everything works pretty good :-)
There is only one thing which is currently not working as I want it.

First of all, I know about the wxGLCanvas class, but the problem is, I'm writing my own Game Engine, which has its own GL Context class and also a Direct3D 11 context class.
So I can't use "wxGLCanvas" or "wxGLContext".

This is actually working, but I can not enable anti-aliasing (i.e. choose an multi-sampling pixel format) for the wxWindow object.

This is how I get the HWND and HDC inside my game engine:

Code: Select all

// Inside my editor:
class MyScreenFrame : public wxWindow { /* ... */ };
MyScreenFrame* myScreen = /* ... */

auto nativeHandle = myScreen->GetHWND(); // <-- Get native HWND handle from wxWidgets

CreateRenderContext(nativeHandle);

// Inside my game engine:
CreateRenderContext(HWND nativeHandle)
{
    HWND hDC = GetDC(nativeHandle); // <-- Get native HDC handle.
    wglChoosePixelFormatARB(hDC, /* ... */); // <-- Choose pixel format with multi-sampling configuration via GL ARB extension. (THIS WILL FAIL)
    /* ... */
}
Can anyone tell me how wxGLCanvas can handle multi-sampling render contexts, so I can do this as well, but with "wxWindow" as base class.

Thanks in advance :-)
OS: Windows 7 Ultimate 64bit
wxVersion: 2.9.2
Compiler: VisualC++ 2008
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doublemax
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Re: OpenGL Context with Anti-Aliasing but without wxGLCanvas

Post by doublemax »

I can only suggest to look into the wx source file and check if there's something missing/different in your code: <wxdir>\src\msw\glcanvas.cpp

Is it possible that you're setting the pixel format more than once? Because there's this comment in the above mentioned file:

Code: Select all

            // from http://msdn.microsoft.com/en-us/library/ms537559(VS.85).aspx:
            //
            //      Setting the pixel format of a window more than once can
            //      lead to significant complications for the Window Manager
            //      and for multithread applications, so it is not allowed. An
            //      application can only set the pixel format of a window one
            //      time. Once a window's pixel format is set, it cannot be
            //      changed.
            //
            // so we need to delete the old window and create the new one
Use the source, Luke!
LukasBanana
Knows some wx things
Knows some wx things
Posts: 27
Joined: Mon Jul 11, 2011 5:02 pm

Re: OpenGL Context with Anti-Aliasing but without wxGLCanvas

Post by LukasBanana »

Yes, I remembered that I re-created the window, when I do my own Win32 programming.

Is there an elegant way to re-create a wxWindow without destroying it completely?
OS: Windows 7 Ultimate 64bit
wxVersion: 2.9.2
Compiler: VisualC++ 2008
LukasBanana
Knows some wx things
Knows some wx things
Posts: 27
Joined: Mon Jul 11, 2011 5:02 pm

Re: OpenGL Context with Anti-Aliasing but without wxGLCanvas

Post by LukasBanana »

Ok by now, I found a very ugly solution (currently with deleting and re-creating the entire wxWindow object).
But maybe I can do this a little better next day.
Thanks anyway :-)
OS: Windows 7 Ultimate 64bit
wxVersion: 2.9.2
Compiler: VisualC++ 2008
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