[Webkit-unassigned] [Bug 266181] New: Advanced tracking and fingerprinting protection performance issues with drawImage

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=266181

            Bug ID: 266181
           Summary: Advanced tracking and fingerprinting protection
                    performance issues with drawImage
           Product: WebKit
           Version: Safari 17
          Hardware: All
                OS: iOS 17
            Status: NEW
          Severity: Major
          Priority: P2
         Component: New Bugs
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: daniel.beauchamp at shopify.com

Description: 

In iOS 17 and mac OS Sonoma, using drawPixels performance is slowed when paired with webgl rendering.

It is a common technique to get around webgl context limitations to render a scene to an offscreen canvas, then output it to a desired 2d canvas using drawImage.
However with Advanced Tracking and Fingerprinting protection, framerate seems to decrease dramatically.

Version:
Latest: 271834 at main



Reproduction steps:
- Open the following in latest: https://evanescent-traveling-radio.glitch.me/
- You should see a box that you can spin smoothly
- Now open it in Privacy mode (which has advanced fingerprinting protection turned on)
- Spinning the box is now sluggish and choppy

If you turn off advanced fingerprinting protection, then suddenly its fast again.

This is the same on iOS 17

The minimal test case code is here: https://gist.github.com/pushmatrix/bd72b5853b49ff217b0a780ea54e5bd5

My assumption is that advanced tracking protection has a false positive here and is introducing noise to the drawImage functionality that is slowing rendering to a crawl.


Impact:
Model viewer (https://modelviewer.dev/) uses this offscreen technique to allow for lots of 3D elements on a page. It is currently affected by this: https://github.com/google/model-viewer/issues/4587

Many sites rely on this technique.

Shopify relies on this viewer for displaying 3D models on hundreds of thousands of sites. Currently anyone viewing it in webkit in privacy mode has a very degraded experience.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20231210/495e15de/attachment.htm>