Re: [pointerevents] Add section explaining what coalesced and predicted events actually *are* in layperson's terms (#361)

just dropping a few thoughts here - the section doesn't have to be long or extensive, but just explain briefly what these events are. My understanding (and please jump in if I'm incorrect) is along the lines of:

> For performance reasons, user agents (and/or operating systems?) may not send a move event every time the position of a pointer is updated. Instead, they will *coalesce* multiple position changes into a single, averaged move event. While this approach helps in reducing the amount of event handling the user agent must perform, it will naturally reduce the granularity and fidelity in use cases such as drawing applications, particularly for fast and large movements. Using `getCoalescedEvents` it is possible for applications to access the raw, un-coalesced position changes. These allow for a more precise handling of pointer movement data. In the case of drawing applications, for instance, the un-coalesced events can be used to draw smoother curves that more closely match the actual movement of a pointer.

Then perhaps adding a graphic to illustrate the point - a smooth curve, indicating the actual `pointermove` points as well as any `getCoalescedEvents` "in-between" points that help draw a smoother, more precise curve. Incidentally, I modified and expanded a nice existing demo of this here today https://patrickhlauke.github.io/touch/coalesced-predicted-events/ ... so something along these lines as a small snapshot/graphic to get the point across.

Need something of similar length/style for `getPredictedEvents()` ... I seem to remember MS writing something up at the time, will see if I can draw (hah!) inspiration for the description from there.

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Received on Friday, 16 April 2021 19:36:32 UTC