Echarts keeps rendering white blanks with large datasets on single canvas mode.

Version

4.8.0

Reproduction link

https://github.com/CarterLi/echarts-bug

Steps to reproduce

1. View the rendered page https://carterli.github.io/echarts-bug/
2. Move mouse on the chart

What is expected?

The chart should work as normal, tooltip should be shown

What is actually happening?

The chart renders white blank

---

Originally found when testing my repo: https://github.com/CarterLi/echarts-with-offscreencanvas

I tested several chart types and found only line chart worked as expected. I have been trying to debug this issue for 2 days and only found the issue happens here:

    _startLoop: function () {
        var self = this;

        this._running = true;

        function step() {
            if (self._running) {

                requestAnimationFrame(step);

                !self._paused && self._update();
            }
        }

        requestAnimationFrame(step);
    },

Of course it was not true, so I gave up.

The issue is rather important to our company, please help

[CarterLi]

It works! Thanks @100pah

Echarts in worker demo can be found here: https://carterli.github.io/echarts-with-offscreencanvas/

[100pah]

@CarterLi

option = {
    // Set this to avoid the issue.
    hoverLayerThreshold: Infinity,
    ...     
};

---

And echarts needs to fix that:

1. Disable the feature of hover layer in when the root dom is canvas
2. Make worker case into the test/**.