radeon EXA performance questions

Clemens Eisserer linuxhippy at gmail.com
Mon Aug 4 10:51:08 PDT 2008


> Firefox uses GetImage when drawing "natively themed" widgets in a web
> page, like buttons or input boxes. (It draws them with GTK+ to a pixmap,
> then gets the image from there and composites it into a page.)

Thats because GTK's theming interface makes it really hard for non gtk
apps/toolkits to use it efficiently, for every widget drawn you have
to readback from vram, which is especially bad with accaleration in
They switched to Cairo with 2.6, but were so afraid breaking the theme
interface that they prefer to create/destroy cairo-contexts for every
small line which is drawn.

Even the  GtkCairoIntegration todo list mentions problems with the
current design:
> 5. Gtk+ themes need to support Cairo surfaces so that e.g.
> insensitivity can be rendered without workarounds (e.g. insensitivity
> for a TreeView cellrenderer rendering Cairo image surfaces)

Wrote a proof-of-concept patch some time ago, but no-one of the gnome
guys found it even worth looking at this:
Even telling me that its crap would have made me happier than
completly ignoring it.

Now GTK-3 is starting to become reality ... and what I have heard its
still not the long-needed re-design, just another extension of the
so-many-times extended/hacked code with only some minor cleanups.

Sorry for the flaming, lg Clemens

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