500k point ScatterGL: unselected points don't fade on second selection

[jonmmease]

Overview

When displaing a scattergl trace with a large number of points (> 500k), the second time the selection tool is used the unselected points don't fade into the background.

To reproduce:

1. Run the following codepen (scattergl with 500k points): https://codepen.io/anon/pen/zjoWpO

2. Perform lasso selection
   

Note that unselected points fade into the background as expeccted

3. Double click to clear selection

4. Perform lasso selection again:
   

Note that now there is no contrast between selected and unselected points

Comments

• This doesn't seem to happen with 10k points
• plotly.js version: 1.36.1
• Chrome version: Version 65.0.3325.181 (Official Build) (64-bit)

[etpinard]

@dy any ideas?

[dy]

Oh, unfortunately that is regl issue, demanding to insert regl._refresh() here and there. I tried to nail it couple of times, to no success, since it requires some complex shader setup. Btw inserting regl._refresh affects drawing performance ~6 times for a thousand of rendering passes, which might be a case for regl-splom or multitrace plots.

[etpinard]

@dy did you file a bug report to regl about this?

[jonmmease]

FWIW I'm not noticing this problem in 1.35.2 (The unselected points keep fading on repeated selections). That version was regl-based as well wasn't it?

I'm also noticing another difference between 1.35.2 and 1.36.1. Take a look at the difference in the initial non-zoomed, non-selected views.

1.35.2

1.36.1

In 1.36.1 the points look less dense. Is there a chance that not all of the points are being rendered in 1.36.1?

[dy]

@etpinard that is really complex shader setup, I am in the process of nailing/issuing the bug.

[alexcjohnson]

In 1.36.1 the points look less dense. Is there a chance that not all of the points are being rendered in 1.36.1?

Is this #2334 again?

It's pretty bad anyway - check out what happens when you make the x values monotonic https://codepen.io/alexcjohnson/pen/GdWEqp