romangg added a comment.
In D10750#486570 <https://phabricator.kde.org/D10750#486570>, @romangg wrote: > Multi-plane support is needed. See @fredrik's inline comment on how to do that: > > > We would need to create a separate EGL image and a separate texture for each plane. > > The scene would need to bind each of those textures to separate texture binding points, and we would need to generate and use a shader that samples texels from each plane and performs YUV to RGB conversion. Going through Weston's code this seems only true for original multi-plane formats, but not for dma-bufs with multiple planes via modifier. See: https://gitlab.freedesktop.org/wayland/weston/blob/5d7877adfd31956bdad98da4a937059260da1f69/libweston/renderer-gl/gl-renderer.c#L2291 While allowing multi-plane for the former would involve some more fundamental changes to KWin since we when need to save multiple textures per WindowPixmap, doing the modifier multi-plane it seems we just receive a single EGLImage which we can then texture from. At least the following revision works with both `weston-simple-dmabuf-egl` and `weston-simple-dmabuf-drm`. And session starts including XWayland (didn't work before). REPOSITORY R108 KWin REVISION DETAIL https://phabricator.kde.org/D10750 To: romangg, #kwin, #plasma, davidedmundson, mart, graesslin, fredrik Cc: meven, zzag, romangg, anthonyfieroni, plasma-devel, kwin, LeGast00n, sbergeron, jraleigh, fbampaloukas, GB_2, mkulinski, ragreen, jackyalcine, Pitel, iodelay, crozbo, bwowk, ZrenBot, ngraham, alexeymin, himcesjf, lesliezhai, ali-mohamed, hardening, jensreuterberg, abetts, sebas, apol, mart