Transparent -> black after upgrade Topic is solved

[Jive Dadson]

I hope this problem rings a bell with someone

I updated a project from wxWidgets 2.8 x86 to wxWidgets 3.1 64bit. Using Visual Studio 2017, VC++17. The project worked well before. Now in some circumstances .ico files with transparent backgrounds are displaying the backgrounds as black.

The main window displays its buttons properly in Release mode. The images for the buttons are compiled into .cpp compilation units, as bit-for-bit copies of .ico files.



Switch to Debug, and this is what I get.



When I display an icon read from a file, it shows up okay at first.



But if I resize it, either larger or smaller, the background goes black.



What else do you need to know? It would be difficult to trim this down to a small program, so I am hoping someone will be able to guess what's happening.

[eranon]

Hello, And what if you explicitely convert the alpha channel to a mask using wxImage::ConvertAlphaToMask()?

[Jive Dadson]

image.ConvertAlphaToMask(gray, gray, gray);

Yessiree. That does the trick. Thanks much!