Does someone has some idea of such weird thing about pixel format?

OpenGL
1

First I call SetPixelFormat which just returns true. Like such:
SetPixelFormat(hdc, 0xa, &pfd);
Immediately following that, I call GetPixelFormat(hdc), but surprisingly it gives back a zero value.I am puzzled.Thanks for any light on this issue.

2

What error code returns GetLastError() ?
(my guess: hdc is invalid; how did you get it?)

3

I get the dc handle from outer application. Is there anyway to conclude a handle is valid or not? Can WindowFromDC be credible? 3X!

4

What do you mean “from outer application”?
Do you try to set a pixelformat in another application’s window? Don’t!

5

oh, sorry, I don’t make me clear. I just wrap SetPixelFormat in a dll.

6

  • SetPixelFormat() returns a boolean. Did it succeed?

  • Do you call this inside DllMain()?
    That might be problematic because it would invoke other DLLs and LoadLibrary() is not allowed inside DLLMain().
    http://msdn2.microsoft.com/en-us/library/ms682583.aspx
    Cite: “It must not call the LoadLibrary or LoadLibraryEx function (or a function that calls these functions), because this may create dependency loops in the DLL load order.”

  • Has the window the necessary window styles WS_CLIPCHILDREN and WS_CLIPSIBLINGS for OpenGL?

7

How and where do you get the hdc?
Do you get it inside the wrapper or is it an argument to it?

(Initializing OpenGL inside DLLMain() sound crazy x_X )

8

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