wayland: Add support for EGLStream client buffers

This commit adds for a new type of buffer being attached to a Wayland
surface: buffers from an EGLStream. These buffers behave very
differently from regular Wayland buffers; instead of each buffer
reperesenting an actual frame, the same buffer is attached over and
over again, and EGL API is used to switch the content of the OpenGL
texture associated with the buffer attached. It more or less
side-tracks the Wayland buffer handling.

It is implemented by creating a MetaWaylandEglStream object, dealing
with the EGLStream state. The lifetime of the MetaWaylandEglStream is
tied to the texture object (CoglTexture), which is referenced-counted
and owned by both the actors and the MetaWaylandBuffer.

When the buffer is reattached and committed, the EGLStream is triggered
to switch the content of the associated texture to the new content.
This means that one cannot keep old texture content around without
copying, so any feature relying on that will effectively be broken.

https://bugzilla.gnome.org/show_bug.cgi?id=773629

1 files changed, 4 insertions, 0 deletions

diff --git a/src/wayland/meta-wayland-surface.c b/src/wayland/meta-wayland-surface.c
index 046806c36..b780c0fdc 100644
--- a/src/wayland/meta-wayland-surface.c
+++ b/src/wayland/meta-wayland-surface.c
@@ -755,14 +755,18 @@ apply_pending_state (MetaWaylandSurface      *surface,
             {
               MetaShapedTexture *stex;
               CoglTexture *texture;
+              CoglSnippet *snippet;
               gboolean is_y_inverted;
 
               stex = meta_surface_actor_get_texture (surface->surface_actor);
               texture = meta_wayland_buffer_get_texture (pending->buffer);
+              snippet = meta_wayland_buffer_create_snippet (pending->buffer);
               is_y_inverted = meta_wayland_buffer_is_y_inverted (pending->buffer);
 
               meta_shaped_texture_set_texture (stex, texture);
+              meta_shaped_texture_set_snippet (stex, snippet);
               meta_shaped_texture_set_is_y_inverted (stex, is_y_inverted);
+              g_clear_pointer (&snippet, cogl_object_unref);
             }
         }