[pointerevents] Consider a simple API for low-latency pointer trails

RByers has just created a new issue for https://github.com/w3c/pointerevents:

== Consider a simple API for low-latency pointer trails ==
In drawing scenarios, having low input->screen latency is extremely important.  In some cases it may be possible for the UA to draw from input to screen faster than an application will ever be able to (even with APIs like offthread canvas which can reliably draw at 60fps).

I wonder if it's worth exposing a declarative API similar to the CSS `cursor` property which can specify an image for the UA to stamp out as a trail behind the pointer for a couple frames (maybe whatever it predicts the typical app input->paint latency is plus a frame of overlap for safety).  This could be used to "close the gap" between the normal lower-latency painting code and the tip of the pointing device (possibly even using a prediction algorithm internally).

We might want some ability to specify separate images for different `pointerType` values, eg. maybe:

  pointer-trail: pentrail.png pen, touchtrail.png touch, none

Please view or discuss this issue at https://github.com/w3c/pointerevents/issues/204 using your GitHub account

Received on Friday, 5 May 2017 19:37:11 UTC