[osg-submissions] GraphicsWindowWin32 fix to prevent resizing window height to zero

[Hautio Jari]

Hi!

Current version of GraphicsWindowWin32 allows resize to zero height
window. This breaks rendering in for example MFC SDI applications and in
MFC MDI applications if user resizes the window so that client area has
zero height. Current safeguard for minimized window:
 
LRESULT GraphicsWindowWin32::handleNativeWindowingEvent( HWND hwnd, UINT
uMsg, WPARAM wParam, LPARAM lParam )
...
        /////////////////
        case WM_MOVE    :
        case WM_SIZE    :
        /////////////////
...
		if (clientRect.bottom==0 && clientRect.right==0)
...

does not cover this situation. In these situations clientRect.bottom = 0
and clientRect.right > 0.

Quick fix to this is relax condition:
		if (clientRect.bottom==0 || clientRect.right==0)

Modified file is attached.

Tested with osgviewerMFC from 2.2.0 release (Windows XP sp2)

Before fix:
 - execute from command line osgviewerMFC.exe cow.osg.
 - the cow is rendered nicely.
 - resize window to zero height by dragging from bottom border upwards.
 - resize window back to original height 
 - just blue screen, no cow

After fix:
 - execute from command line osgviewerMFC.exe cow.osg.
 - the cow is rendered nicely.
 - resize window to zero height by dragging from bottom border upwards.
 - resize window back to original height 
 - the cow is where it is supposed to be.

Cheers,

Jari Hautio
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