Why does the GTK3 vcl sal plugin default to SvpSalGraphics / software rendering?

[Clemens Eisserer]

Hi,

I am currently analyzing performance issues when scrolling larger
images in writer on linux, especially when they have an alpha channel:
https://bugs.documentfoundation.org/show_bug.cgi?id=115702
https://bugs.documentfoundation.org/show_bug.cgi?id=80659
https://bugs.documentfoundation.org/show_bug.cgi?id=87485

Some reports indicate that the GTK3 vcl backend seems to be particulary bad.

While investigaing, I found that with the GTK3 backend all rendering
is done with SvpSalGraphics in software / on the CPU.
I wonder what was the relationale behind this decision? And is this
the right mailing list to ask vcl implementation details?

Best regards, Clemens