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Re: TheIDE Format Setup BUG [message #29889 is a reply to message #29884]

Sat, 27 November 2010 18:38

dolik.rce
Messages: 1789
Registered: August 2008
Location: Czech Republic

Ultimate Contributor

Forget most of what I said in my previous post Smile

I dug deeper and found out that the reason why XGetImage fails is most probably that it is called on an image with one dimension equal to zero. The other calls are guarded against such thing, but this one for alpha layer was left unprotected.

I believe that if the image is empty (that is zero pixels in any direction, or in code GetSize().IsEmpty()==true), we don't have to bother drawing it at all, right? Or are there some side effects I didn't notice? I'd suggest something like:

ImageDraw::operator Image() const
{
	if(size.IsEmpty()){              // this block is added
		ImageBuffer ib(size);
		return ib;
	}
	GuiLock __;
	XImage *xim = XGetImage(Xdisplay, dw, 0, 0, max(size.cx, 1), max(size.cy, 1), AllPlanes, ZPixmap);
	Visual *v = DefaultVisual(Xdisplay, Xscreenno);
	RasterFormat fmt;

	RGBA   palette[256];
// ...
}

For me it works fine and eliminates the crashes. The roll-out animation of color selector even looks a bit smoother now (but that might be just my imagination Smile

).

Oh, and I almost forgot to mention that the troublesome call to this operator Image() is located in Image WheelRampCtrl::PaintWheel(Size size) in DlgColor.cpp, in the "return iw;" statement (iw is the empty ImageDraw) where implicit conversion to Image happens.

Honza

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