input_pipeline > PointerMotionDisplayScaleHandler

Scales pointer motion, to make the physical size of pointer motion invariant to display resolution. This allows products to use stock mice and trackpads with high-DPI displays, without having to implement pointer acceleration algorithms.

Notes:

• This handler is only suitable when the high-DPI display is used for smoother rendering of content, rather than for fitting more content onto a screen. In the latter case, scaling the pointer motion may make it difficult to hit the exact desired pixel.
• This handler deliberately deals only in UnhandledInputEvents. That's because most handlers send an event to a FIDL peer before marking the event as handled. Scaling an event that has already been sent to FIDL peers might lead to inconsistencies, if another handler downstream from this handler also sends pointer events to FIDL peers.