Dragging the slide with touch causes poor performance

[logaretm]

Describe the bug

When dragging slides with a touch device (tested on my Surfacebook) the slides are extremely laggy, drops to 5 fps in during the dragging. However results differ on other browsers:

Tested browsers:

• Firefox ✔
• Chrome ❌
• Edge (Pre-Chromium) ❌ doesn't even respond to the touch move event.
• Edge Beta (Chromium) ❌

It seems related to preventing a "passive" event related to the touchstart.

https://github.com/baianat/hooper/blob/master/src/Hooper.vue#L383

https://github.com/baianat/hooper/blob/master/src/Hooper.vue#L394

To Reproduce
Steps to reproduce the behavior:

1. Got to the examples page on any touch-capable device.
2. Drag slides using touch.
3. Drag using a mouse to compare perceived performance.

Expected behavior
The slide should smoothly follow the touch position like the mouse.

Screenshots

Additional context

The logs report a bunch of errors and warnings, the relevant ones are:

Unable to preventDefault inside passive event listener invocation.

[Intervention] Unable to preventDefault inside passive event listener due to the target being treated as passive. See <URL>

This is the captured profile on my device

Profile-20190624T131003.zip