feat(tooltip): Allow tooltips to disable transform positioning

[scttcper]

Brief Information

This pull request is in the type of:

• bug fixing
• new feature
• others

What does this PR do?

In #14246 echarts v5 css transform was made the default for positioning tooltips based on if the browser is modern. We'd like to be able to switch back to the old left, top absolute positioning as we've found that transform is slower when attempting to follow the cursor. After removing the new drop-shadow, its close but still not nearly as performant when scrubbing quickly.

echarts v4

Layouts per second - 300

Kapture.2021-11-22.at.16.52.01.mp4

echarts v5.2.2 with tooltip dropshadow removed

Layouts per second - 170

Kapture.2021-11-22.at.16.51.41.mp4

Fixed issues

Details

Before: What was the problem?

After: How is it fixed in this PR?

Misc

• The API has been changed (apache/echarts-doc#xxx).
• This PR depends on ZRender changes (ecomfe/zrender#xxx).

Related test cases or examples to use the new APIs

NA.

Others

Merging options

• Please squash the commits into a single one when merge.

Other information

[echarts-bot]

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[plainheart]

What you are expecting is to get the tooltip closely followed with the mouse, that is, hope it has no delay, right? Because the position is updated frequently in a short duration, we throttled the tooltip's trigger frequency in #15683 to solve the shaking and lagging issue in the connected charts or when the devtools is open. In such a case you mentioned, it may be a good choice to set tooltip.transitionDuration to be 0. But it seems the new change also brings some negative effects. It appears a bit lagging when transitionDuration is 0, which is not good as v5.2.0 or earlier.

[scttcper]

@plainheart yes, exactly. we're using transitionDuration: 0 and looking to closely follow the mouse. I'll take a look at that debounce

[scttcper]

Opened #16101 instead, it does seem to be that throttle function, but removing it does trigger the dev tools issue