# OIDN wgpu interoperability
[](https://crates.io/crates/oidn-wgpu-interop)
[](https://github.com/Vecvec/oidn-wgpu-interop/actions/workflows/ci.yml)
---
A helper library to create shared buffers between OIDN and
wgpu.
## Getting started
### Creating the device
Simply replace the `adapter.request_device` call with
`oidn_wgpu_interop::Device::new` (using
`adapter.request_device` only if
`oidn_wgpu_interop::Device::new` fails). You are then able
to call `device.wgpu_device` to get the created wgpu device
and `device.oidn_device` to get the OIDN device.
### Creating shared buffers
To create a shared buffer call
`device.allocate_shared_buffers`. The shared buffer may be
used with usages
`BufferUsages::COPY_SRC | BufferUsages::COPY_DST`. To get
the wgpu buffer call `buffer.wgpu_buffer` and to get the
OIDN buffer call `buffer.oidn_buffer`. It is recommended to
minimise the number of shared buffers that exist at a given
time due to them each requiring a separate allocation.
## Synchronisation
There is no synchronisation between OIDN and wgpu currently
possible. This lack of synchronisation means that after
using any `SharedBuffer` in wgpu, but before using it with
OIDN, all wgpu command buffers that use the shared buffer
must finish. The same must happen in the opposite direction,
any OIDN functions that use this buffer must have finished.
## Platform Support
Currently, this only supports DirectX12 and Vulkan (on
Windows using `VK_KHR_external_memory_win32`). This code
could be expanded to Vulkan (on Linux using
`VK_KHR_external_memory_fd`) and Metal. Due to some devices
being unsupported by OIDN it is recommended to support a
mode that copies to the cpu and then into an OIDN buffer
anyway.