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GLControl flicker when covered by window #10

thefiddler opened this Issue · 2 comments

1 participant


Originally posted at

"I have been working for 2 years with 2010 opengl version with no problems. I have updated to 2013 and now, with ATI, if a tooltip or child window overlaps the opengl context, that dirty region is repainted, but not the rest! Any Idea?"

The issue appears to be caused by d9afed2 and disappears when reverted.

However, according to MSDN, the changes brought in by this commit are suggested or required for OpenGL on Windows. From

"An OpenGL window has its own pixel format. Because of this, only device contexts retrieved for the client area of an OpenGL window are allowed to draw into the window. As a result, an OpenGL window should be created with the WS_CLIPCHILDREN and WS_CLIPSIBLINGS styles. Additionally, the window class attribute should not include the CS_PARENTDC style."

Which means that according to the official documentation, this commit is actually correct.

More information about the impact of this change is required:

  • is this issue specific to Ati cards, or does it also appear on Nvidia / Intel?
  • is it possible that this limitation was relaxed on Vista+ (due to the DWM)? If we revert this commit, do we still get correct behavior on WinXP?

Workaround added in ca36c6f


A fix has been added to the 2013-12-05 release. If this is issue remains, please re-open.

@thefiddler thefiddler closed this
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