D10750: wayland: Add support for zwp_linux_dmabuf

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

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