Wire resistivity slider laggy when all items in play area

[ghost]

Test Device

MacBook Air

Operating System

macOS 10.14.3

Browser

Google Chrome 74.0.3729.131

Problem Description

For phetsims/qa#314. If all items are in the play area, the wire resistivity slider can be laggy. See gif. Happens for both CCK:DC and CCK:DC-VL.

Steps to Reproduce

1. Add all or most items to the play area.
2. Adjust wire resistivity slider.

Screenshots

Troubleshooting Information

Name: ‪Circuit Construction Kit: DC - Virtual Lab‬ URL: https://phet-dev.colorado.edu/html/circuit-construction-kit-dc-virtual-lab/1.1.0-dev.1/phet/circuit-construction-kit-dc-virtual-lab_en_phet.html Version: 1.1.0-dev.1 2019-05-06 21:22:27 UTC Features missing: touch User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.131 Safari/537.36 Language: en-US Window: 1440x821 Pixel Ratio: 1/1 WebGL: WebGL 1.0 (OpenGL ES 2.0 Chromium) GLSL: WebGL GLSL ES 1.0 (OpenGL ES GLSL ES 1.0 Chromium) Vendor: WebKit (WebKit WebGL) Vertex: attribs: 16 varying: 15 uniform: 1024 Texture: size: 16384 imageUnits: 16 (vertex: 16, combined: 80) Max viewport: 16384x16384 OES_texture_float: true Dependencies JSON: {}

[ghost]

Same thing happens on the latest version of iOS.

[ghost]

Side note: moving the items around can cause significant lag on iOS, but it's not consistent. Let me know if I should make a separate issue.

[samreid]

Does the latest published version exhibit this same performance degradation?

[samreid]

@ariel-phet do you want me to investigate this before moving to RC.1?

[ariel-phet]

@lmulhall-phet @KatieWoe please check if the same occurs in the published version

@samreid if the same issue exists in the published version, no need to address for RC.1

[KatieWoe]

It does occur in the published sim @samreid

[samreid]

This problem seems somewhat reduced in master on my MacOS laptop. When I test the published version and drag out every component, I see a moderate lag. When I test requirejs, I see a small amount of lag. I ran the profiler and it shows the effort is in the circuit solve step, I'm not sure how we could avoid that.

I published a dev version for comparison, but on second thought want to make sure the physics engine is working correctly before testing this again:
https://phet-dev.colorado.edu/html/circuit-construction-kit-dc/1.2.0-dev.1/phet/circuit-construction-kit-dc_en_phet.html

On hold for a while.