Currently, Encoder.reset() must make a round trip to the sensor and back
in order for the count to be updated for the user program. As the sim layer
also resets the internal encoder count, this creates a race condition (a WS
message with a new count can be "in flight" during a reset and update the
count).
This changes the WS layer to not put reset on the wire, but instead keep an
offset count internal to the robot program. The value on the wire is not
reset, but rather all sends and receives are adjusted as necessary to the
internal robot count.
This approach is straightforward, but does result in the value on the wire
not matching the value in the user program. A future improvement will fix
this, but this change fixes the immediate race condition problem.
This allows access to HAL-level simulation data via a WebSocket connection.
The server additionally serves local files.
The following environment variables can be used for configuration:
HALSIMWS_USERROOT (server) - local directory to use for file serving for /user/ URIs, defaults to ./sim/user
HALSIMWS_SYSROOT (server) - local directory to use for file serving for all other URIs, defaults to ./sim
HALSIMWS_URI (client or server) - WebSocket URI, defaults to /wpilibws
HALSIMWS_PORT (client or server) - port number, defaults to 8080
HALSIMWS_HOST (client) - host to connect to, defaults to localhost
Co-authored-by: Zhiquan Yeo <zyeo8@bloomberg.net>
Co-authored-by: Peter Johnson <johnson.peter@gmail.com>
Co-authored-by: jpokornyiii <jpokornyiii@gmail.com>
