I believe this to be a bug with Avogadro: initially (soon after the first installation) the main window background is fully transparent (i.e. the other windows and the desktop background are fully visible through it). After setting any color for background, it turns opaque and this setting is preserved after exiting Avogadro. However, the blue halo for selected atoms still makes them transparent (i.e. the content of underlying windows can be viewed through the selected atoms). This latter effect is persistent after exiting and re-entering.
The same problems were also detected on a different laptop, with a different NVidia GPU.
Environment Information
Avogadro version: 1.94.0
Operating system and version:
Windows 10 (64-bit):
Edition: Windows 10 Home - Version: 20H2
Installed on:14/03/202 - OS Build: 19042.1052
Windows Feature Experience Pack 120.2212.2020.0
Graphics: Intel(R) HD Graphics 630/NVIDIA GeForce GTX 1080
NVidia Driver: 466.77
Expected Behavior
Opaque white or black default window background.
Opaque selection halos.
Actual Behavior
Transparent default window background, turning to opaque only after bg color change.
Transparent selection halos.
Steps to Reproduce
Start Avogadro after a fresh install → for transparent bg
Select Atoms (always) → for transparent selection halos
First test: The fix works flawlessly. Initial background is opaque and selection halos are, as expected, half-transparent over opaque objects (atom and surrounding background).
The saved png file has a trasparent bg (independently on background color in the program: tested black, white, green).
Incidentally, when saving the png file, the mol window bg turns transparent for a fraction of second.
Also incidentally, now inserting both fragments and SMILES string works. However, before posting this result in the proper section, I want to check more extensively these features.
Excellent! I should make that an option since the background may be desired, but it’s very convenient when I want to paste a transparent PNG into slides.
Fingers crossed.
Your testing is very helpful, and bit by bit we can release a polished 2.0.