w3c / sensors

Generic Sensor API
https://www.w3.org/TR/generic-sensor/
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Tighten the Sensor.timestamp and latest reading["timestamp"] definitions #469

Closed rakuco closed 11 months ago

rakuco commented 11 months ago

latest reading["timestamp"] was not defined strictly enough: the definition mentioned "the time origin", which is a concept that only exists related to a given environment settings object.

We now have it be an "unsafe current time" as defined by the High Resolution Time specification, and its value is always set using the same monotonic clock -- if we get a timestamp directly from a device sensor (e.g. a WinRT timestamp relative to the Windows epoch) it needs to be translated into a timestamp that makes sense with the monotonic clock.

Finally, Sensor.timestamp no longer just returns latest reading["timestamp"] and instead ensures that whatever "unsafe current time" the latter returns is coarsened and converted to a value relative to its relevant time origin.

Related to #463.


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