This directory contains files from the OpenVR SDK, version 1.0.18.

This SDK contains the OpenVR API interface headers and functions to load the
OpenVR runtime libraries which actually implement the functionality. The
loading functions parse a .json file in a pre-defined location on the
end-user's machine to get details used to bind the correct runtime library.
The OpenVR implementation ensures forward and backwards compatibility as of
the current version.

Updated versions of the OpenVR SDK are available on Github:

https://github.com/ValveSoftware/openvr


We only use some files from the SDK:

- We strip out files such as C# headers, plain C API versions, and files
  needed only when implementing OpenVR drivers.

- CMake related files, such as CMakeLists.txt are skipped as we use moz.build
  files to configure the library.

- The "src/jsoncpp.cpp" file and the "src/json" directory can be skipped. OpenVR
  uses the jsoncpp library, which we have already imported elsewhere.


Steps to update the library:

- Copy "README.md" from the root of the openvr repo to the "gfx/vr/openvr" directory.

- Copy "headers/openvr.h" to "gfx/vr/openvr/headers" directory. The other files
  in this directory can be ignored.

- The rest of the files in the "src" directory and the "src/vrcommon" are copied
  to the "gfx/vr/openvr/src" directory.

- Update "gfx/vr/openvr/moz.build" when files are added or removed.

- Update the "strtools_public.h" and "strtools_public.cpp" files, commenting out
  the "Uint64ToString", "wcsncpy_s", and "strncpy_s" functions.
  The "Uint64ToString" function name conflicts with another used in Gecko and
  the "errno_t" return type returned by the other functions is not defined in
  Mozilla's macOS continuous integration build environments.  Fortunately, the
  OpenVR SDK does not use these functions.

- Replace the #define VR_INTERFACE in openvr.h to avoid extern'ing the functions.
  Unlike the usual OpenVR API builds, we are not building a separate dll.

- Update this README.mozilla file with the new OpenVR SDK version and any
  additional steps needed for newer versions.

- Ensure that any changes made within the OpenVR files have comments including
  the string "Mozilla" and reference this file for easy identification.