We have code with proper error handling for dmabuf export, we can just
try to use it.
And if it doesn't work, we don't offload the texture like before.
But it does work - at least for me.
Instead of hardcoding which textures we presumably support, just try
creating a buffer and use the failure of that for the error message.
This makes the error message a bit less obvious, but it makes it
possible to refactor the get_buffer() code without having to deal with
the error path.
If we want to improve the debug message, we can start putting debug
messages into the get_buffer() function.
But I think this is good enough.
Use a format of
[XXX] SYMBOL DETAILS
where SYMBOL indicates the offloading status:
🗙 - no offload
▲ - offload above, with background
△ - offload above, no background
▼ - offload below, with background
▽ - offload below, no background
Do the same checks for background coordinates that we do for the
subsurface coordinates themselves: they must be integral in both
application and device pixels.
Spew a bit less per-frame. Unfortunately, we still spew for
every frame, and fixing that would require more extensive
refactoring to centralize all logging in gskoffload.c
Only commit things that have changed. In the ideal scenario, only
the texture changes from frame to frame, and all the sizing related
setup and the background stay the same, causing the least amount
of work in the compositor.
Rename things so they make more sense. The dest/source naming got
a bit unclear when we added background into the mix. Now we're going
for:
source_rect - the texture region to display
texture_rect - dimensions of the subsurface showing the texture
background_rect - dimensions of the background subsurface
bounds - union of texture_rect and background_rect
Also use this opportunity to add some api docs.
Make it possible for subsurfaces to have a black background on a
secondary subsurface below the actual subsurface. Using a single-pixel
buffer for that background increases the changes that the compositor
will use direct scanout for the actual subsurface.
This changes the private subsurface API. All callers have been
updated to pass an empty background rect.
This is useful for debugging offloading without having to rely
on gstreamer giving us dmabufs. To use it, set
GDK_DEBUG=force-offload
in the environment.
Allow to specify a D₂ transform when attaching a texture to a
subsurface, to handle flipped and rotated content. The Wayland
implementation handles these transforms by setting a buffer
transform on the subsurface.
All callers have been updated to pass GDK_TEXTURE_TRANSFORM_NORMAL.
This will let us use a subset of the full texture, which can
be necessary in the case that converters put padding around
content in dmabufs. The naming follows the Wayland viewporter
spec.
For now, make all callers pass the full texture rect.
We are going to introduce another rect, so better to be clear in
naming. We are following the naming of the Wayland viewporter spec
and call the rectangle that we drawing into the dest(ination).
We accept transparent subsurfaces for passthrough now, when they are
above the surface.
But we did not unset the opaque region to empty when the texture is
transprent.
Sadly, subsurface positioning is undefined in this case. We'll
trust the compositor to not mess up if the device coordinates
after applying the scale are integral, but otherwise, we'll
decline.
Instead, do it all in attach(), which becomes more and more like
ConfigureWindow. This is good, because it will let us take the
above-ness into account when making decisions about attaching.
There was one branch in the success case that turned it into a failure,
yet we were still reporting a success (and discarding the buffer).
Don't do that.
