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I’ve noticed that RGB/A icons drawn using Prof UIS don’t have as smooth edges as when drawn by MFC.  There seems to be a difference with how the alpha channel is processed.

Is there anything that can done  to improve this?

Please accept my apologies for thinking I knew better!  The following does indeed work :)

CExtBitmap::LoadBMP_Resource();

CExtBitmap::AlphaBlend();

I don’t think you are right.

The alpha channel is being handled by the Prof UIS API - but it is drawn darker than DrawIconEx() does.

The loaded icon is not being reduced to low colour & no image lists are needed to show the problem.

I am right in thinking Prof UIS has its own alpha-channel algorithms?  If so I believe the problem is either CExtBitmap::AssignFromHICON() or CExtBitmap::AlphaBlend().  This is easily demonstated by performing the steps I mentioned in my earlier post.

This may be a specific problem for a particular computer. Because nobody reported similar issue yet. The CExtBitmap::AlphaBlend() API uses the only available Win32 API for alpha channel output: the AlphaBlend() function from MsImg32.dll module. Other icon painting APIs should do the same.

The following draws the alpha channel correctly:

LoadImage()

DrawIconEx()

The following draws grey pixels around the edge that shouldn’t be there & gives a slightly jagged look

LoadImage()

CExtBitmap::AssignFromHICON()

CExtBitmap::AlphaBlend()

CExtToolControlBar, CExtGridWnd, etc. all draw icons incorrectly.

The problem can be hidden in the LoadImage() Win32 API or Windows image list APIs used by the AssignFromHICON() method. Both Win32 API may prefer a non-32-bit version of the icon image and choose a low color version instead. The solution is to never use ICO files and resources. Use 32-bit BMP and PNG files instead.

Prof-UIS fully manages BMP formats including the alpha channel. We need more details about what’s wrong with the icons in apps running on your PC.

I’ll post a sample project when I get a chance.

Prof UIS is definately processing the alpha channel, its just drawing the edges a bit darker than MFC does, giving a more jagged look.

Please provide us with more details and/or screen shots.