[Lazarus] Alpha blending in GTK2 under Linux

[Valdas Jankūnas]

2017.04.14 22:02, Marc Weustink via Lazarus rašė:

>> Why GTK2 "screen" not supports alpha?
>>  It is strange because if I load PNG with transparency (image with
>> gradient) into TImage then I clearly can see alpha blending effect on
>> GTK2 when image is diplayed.
>
> Iirc (its long ago when i implemented it) the alphablending is done by the underlying rawimage implementation
>
> Marc

I tried to put 32 bit image in to TImage (on GTK2) and alphablending 
works. Is this means that I can always put an image with 32 bit depth in 
to TImage when "GetDescriptionFromDevice(0)" says "screen" supports 
"Depth: 24"? If not always then how to know when I can?


-- 
   Valdas Jankūnas