mirror of
https://gitlab.freedesktop.org/monado/monado.git
synced 2024-12-28 18:46:18 +00:00
44 lines
1.9 KiB
Markdown
44 lines
1.9 KiB
Markdown
|
# Spaces in Monado design {#design-spaces}
|
||
|
|
|
||
|
|
<!--
|
||
|
|
Copyright 2022-2023, Collabora, Ltd. and the Monado contributors
|
||
|
|
SPDX-License-Identifier: BSL-1.0
|
||
|
|
-->
|
||
|
|
|
||
|
|
## Goals
|
||
|
|
|
||
|
|
* Hold a super set of the semantic spaces that OpenXR requires, local, stage,
|
||
|
|
unbounded, etc...
|
||
|
|
* Allow devices to be attached to other devices.
|
||
|
|
* Generating events when a space is moved, dealing with the requirement that
|
||
|
|
the move only happens after a certain time in the future.
|
||
|
|
* Make the internal graph be simple and non-cyclic.
|
||
|
|
* No bi-directional links.
|
||
|
|
* Always have a root object.
|
||
|
|
|
||
|
|
## Overall design
|
||
|
|
|
||
|
|
The `xrt_space` object is fairly straight forward, it's a space. Some have
|
||
|
|
semantic meaning like local, stage, unbounded. The `xrt_space_overseer` object
|
||
|
|
is where most of the interesting things happens. By having a separate object
|
||
|
|
where functionality is implemented we can handle things like: different sessions
|
||
|
|
with different spaces, have a object that space events comes from. It also makes
|
||
|
|
it easier for the IPC layer to implement it.
|
||
|
|
|
||
|
|
## Issues & questions
|
||
|
|
|
||
|
|
* Where do space events come from?
|
||
|
|
* **UNRESOLVED:** Probably will come from the space overseer.
|
||
|
|
* Do we map all spaces one to one, like the each `XrSpace` with an offset gets
|
||
|
|
backed with a `xrt_space`. There is going to be a limit on spaces from the
|
||
|
|
point of view of the IPC layer, do we create some of them locally?
|
||
|
|
* **RESOLVED:** While you can create a offset `xrt_space`, the offsets from
|
||
|
|
from the `XrSpace`s are not expressed as an `xrt_space` this is to reduce
|
||
|
|
the number of spaces created.
|
||
|
|
* For the IPC gap do we mirror the entire space graph between the app side and
|
||
|
|
the service side. Or is it enough to only expose the spaces/nodes a app needs
|
||
|
|
and keep all of the links on the service side only.
|
||
|
|
* **RESOLVED:** The graph is kept opaque from the application (and all other
|
||
|
|
parts of Monado, an space overseer has greater freedom in how to configure
|
||
|
|
the space graph).
|