[fdo] Need help with XRenderSetPictureFilter

[Nikita Zlobin]

Thanks, will look to xorg lists too.

Btw, I forgot that also saw 'SetPictureFilter' in renderproto. Still
nothing new. I queried filters for same picture's drawable (xpixmap),
and it has convolution in the list. If that's not list of effects,
available for pixmap, than what (I use only one screen).

In Mon, 21 Feb 2022 09:49:49 -0800
Alan Coopersmith <alan.coopersmith at oracle.com> wrote:

> I've cc'ed the xorg mailing list, since that's a better place to ask
> than the generic freedesktop mailing list.
> 
> https://gitlab.freedesktop.org/xorg/proto/xorgproto/-/blob/master/renderproto.txt#L728
> says that you'll get a BadMatch error if the specified filter is not
> "one of the filters supported for the screen associated with picture".
> 
> On 2/21/22 07:11, Nikita Zlobin wrote:
> > I'm trying to apply convolution to pixmap:
> > 
> > Doing this call before to composite:
> > 
> > XRenderSetPictureFilter (
> >      display, pic_src, "convolution",
> >      (XFixed[]){ 3, 1, 0x2AAAAAAB, 0x2AAAAAAB, 0x2AAAAAAB },
> >      5 );
> > 
> > Found this function in the header - it's missing both in
> > renderproto.txt and libXrender.txt files. Parameters should be just
> > as described for convolution filter: N + M + N*M values in total.
> > 
> > Error happens right here:
> > 
> > X Error of failed request:  BadMatch (invalid parameter attributes)
> >    Major opcode of failed request:  138 (RENDER)
> >    Minor opcode of failed request:  30 (RenderSetPictureFilter)
> >    Serial number of failed request:  48
> >    Current serial number in output stream:  50
> > 
> > Tried to analyze existing code - in picom, but it uses xcb, yet I
> > can't anything specific. The only difference - xcb function has
> > different order for params number and array, plus filter name
> > length.
> > 
> > I made assumption, that XFixes should take full 32bit range
> > (signed), so just took maximum signed 32bit value and divided by 3.
> > 
> > Error mentions something called parameter attributes. Can't see
> > anything, but values in function signature.
> 
>