[Bug] PathLayer is "fuzzier" after upgrading to deck.gl 9.2 when passing `useDevicePixels: true`

[kylebarron]

Description

Here's deck.gl 9.2:

deck9.2_1080.mov

Here's deck.gl 9.1:

9.1_1080.mov

The only commit in between them is this Lonboard PR that upgrades to deck.gl 9.2.

Flavors

• Script tag
• React
• Python/Jupyter notebook
• MapboxOverlay
• GoogleMapsOverlay
• CARTO
• ArcGIS

Expected Behavior

No response

Steps to Reproduce

The easiest way to reproduce what I'm seeing is through Lonboard. It's this Python notebook in the Lonboard docs

git clone https://github.com/developmentseed/lonboard
cd lonboard
uv install
npm install
npm run build:watch
ANYWIDGET_HMR=1 uv run --group watchfiles jupyter lab

And then go to the north-america-roads.ipynb example

I'm really slow at making codepens because I don't work in JS often, so hopefully it's easy to spot what's going on 😬. Otherwise I can make a codepen in a follow up

Environment

• Framework version: 9.2.1
• Browser: Chrome 141.0.7390.54
• OS: macos 15.6.1

Logs

I get notes about This version of luma.gl has already been initialized, but I see those often and I don't think those are related.

[kylebarron]

I see this on multiple layers, and seems to have something to do with canvas reload/refresh.

For example, here's a screencast of the layers becoming fuzzy after a re-render when setting interleaved: false

Screen.Recording.2025-10-14.at.10.58.08.PM.mov

In conversation with @felixpalmer (somewhat just notes to self)

There was a canvas resize handling refactor in the last luma, so perhaps it is rendering with pixelRatio when it shouldn't be

drawingBufferHeight is potentially wrong. In general you could try to compare to 9.1

[kylebarron]

I do consistently see this on canvas resizing. Here, the polygon layer becomes fuzzier when the sidebar is opened.

Screen.Recording.2025-10-17.at.5.31.11.PM.mov

[Pessimistress]

Can you check if context. drawingBufferWidth and context. drawingBufferHeight are resized with the canvas?

[kylebarron]

Testing with opening and closing the sidebar, yes, deck.device.canvasContext.drawingBufferWidth does resize between 850 and 583, in this case.

But it's hard to get to a state where it's not fuzzy. Most of the time I render a map with Lonboard now, and it's only a couple times that I've seen it crisp (so I took the screencast).

FWIW I do see this error when opening and closing the sidebar. Not sure if it's related. Monday I can go and check if I got the same error with 9.1.

89cde327-3e3d-4241-abde-82367ead5069:31341 Uncaught TypeError: Cannot read properties of undefined (reading 'maxTextureDimension2D')
    at WebGLCanvasContext.getMaxDrawingBufferSize (89cde327-3e3d-4241-abde-82367ead5069:31341:56)
    at WebGLCanvasContext._handleResize (89cde327-3e3d-4241-abde-82367ead5069:31429:66)
    at ResizeObserver.callback (89cde327-3e3d-4241-abde-82367ead5069:31293:71)
    at ResizeObserver._delayCallbackInScrollingNotebook (jlab_core.084a1862d3b52384fe1b.js?v=084a1862d3b52384fe1b:1:1207172)
    at ResizeObserver.<anonymous> (jlab_core.084a1862d3b52384fe1b.js?v=084a1862d3b52384fe1b:1:1206972)
getMaxDrawingBufferSize @ 89cde327-3e3d-4241-abde-82367ead5069:31341
_handleResize @ 89cde327-3e3d-4241-abde-82367ead5069:31429
(anonymous) @ 89cde327-3e3d-4241-abde-82367ead5069:31293
(anonymous) @ jlab_core.084a1862d3b52384fe1b.js?v=084a1862d3b52384fe1b:1
(anonymous) @ jlab_core.084a1862d3b52384fe1b.js?v=084a1862d3b52384fe1b:1

[kylebarron]

Thanks to @felixpalmer 's help, I verified that passing

useDevicePixels: true

causes this behavior.

Removing that line and leaving useDevicePixels as undefined ensures that PathLayer is rendered crisp:

useDevicePixels: true	useDevicePixels: undefined

This is confusing to me given that the docs say the default value is true