How to enable partial redraws for Blender?

[Rush-iam]

For some apps, Xpra redraws only updated parts, but for Blender, it always redraws the entire screen, even if I change a small screen value, or hover a button/menu. It makes Blender less responsive, I get a few fps even doing small things.

Is there a way to enable redrawing only updated parts?
I suppose Blender is an OpenGL application, accelerated by VirtualGL.

[totaam]

Is there a way to enable redrawing only updated parts?

My guess is that blender is detected as a video application, as such it will tend to use video encodings and those only handle full-window redraws.
Please include the xpra info for the window affected.

[totaam]

Wait, are you using the html5 client?

[Rush-iam]

Yes. This thread is in html-client repo also

[totaam]

Oops, I somehow missed that!
You should try with the python client to see if it fares any better.
If it does then we know the html5 client just needs scroll implemented.

[Rush-iam]

I am restricted to the HTML client only, unfortunately.

But I reverted 6be1053 locally (it is probably not enough, as I don't get related visual issues) and ran Xpra with -d scroll. Here is what I see in the logs:

2024-02-26 17:23:24,658 may_use_scrolling(XShmImageWrapper(BGRX: 0, 0, 3744, 2066), {'quality': 75, 'speed': 71, 'rgb_formats': ('RGBX', 'RGBA', 'RGB'), 'lz4': True}) supports_scrolling=False, has_pixels=<built-in method has_pixels of xpra.x11.bindings.ximage.XShmImageWrapper object at 0x7f59e05a1870>, content_type=, non-video encodings=('png', 'webp', 'rgb24', 'rgb32', 'jpeg')
2024-02-26 17:23:24,658 no scrolling: not supported

What does it mean?

[totaam]

https://github.com/Xpra-org/xpra/blob/5bec0e8a1544fb265ef7f018f235486398777649/xpra/server/window/video_compress.py#L454
Means that at least one end does not support scroll encoding.