Visiting the "Peaks of Austria" page at https://felixpalmer.github.io/peaks-of-austria with privacy.resistFingerprinting=true results in a confused/broken rendering, as shown in the attached screenshot produced using:

mozregression --pref privacy.resistFingerprinting:true -a https://felixpalmer.github.io/peaks-of-austria

The issue appears on Firefox 84.0 and current nightlies. Both tested on Debian testing with Intel 3rd Gen Core processor graphics.

The website source is available at https://github.com/felixpalmer/peaks-of-austria I have not reached out to the author yet, but would be willing to do so if that would be helpful.

Still reproduces on Linux / NVIDIA proprietary / current Nightly 95.

I'm guessing this is because of

Blocked https://felixpalmer.github.io/peaks-of-austria/ from extracting canvas data because no user input was detected. procedural-gl.js:41474:27

So I think this is expected.

When you load https://felixpalmer.github.io/peaks-of-austria/ you will see a canvas icon in the urlbar, you can click this and allow (or allow for session by unchecking Remember this decision

Can probably be duped to Bug 1631673 which is a bit of a think tank on this problem

• we reduced prompt fatigue with privacy.resistFingerprinting.autoDeclineNoUserInputCanvasPrompts
• now as more site use canvas, the lack of education on RFP (it is not front facing) and the silent breakage is becoming more problematic
• possibly auto-allowing per eTLD+1 per session after a user-gesture (which is problematic as eliciting a gesture is not hard)

tom? dupe to Bug 1631673

Thanks all for weighing in on this issue!

(In reply to Simon Mainey from comment #3)

When you load https://felixpalmer.github.io/peaks-of-austria/ you will see a canvas icon in the urlbar, you can click this and allow (or allow for session by unchecking Remember this decision

I gave this a shot with 95.0a1 (2021-10-07) (64-bit) launched via mozregression:

mozregression --pref privacy.resistFingerprinting:true -a https://felixpalmer.github.io/peaks-of-austria --launch 2021-10-07

After clicking Allow (and force-reloading) the rendering is still broken for me. (Screenshot attached.) Without --pref privacy.resistFingerprinting:true it renders correctly with 95.0a1 (2021-10-07) (64-bit).

I have to admit I didn't actually test it, sorry ... however, I don't think that's RFP ... I see console errors galore (also on Nightly 95)

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://maps1.wien.gv.........

(In reply to Simon Mainey from comment #5)

I have to admit I didn't actually test it, sorry ... however, I don't think that's RFP ... I see console errors galore (also on Nightly 95)

No worries, still a good suggestion. I don't mind doing the testing. I am also seeing the "Cross-Origin Request Blocked" console errors, but the site works for me with mozregression -a https://felixpalmer.github.io/peaks-of-austria --launch 2021-10-07 in spite of the errors and not with --pref privacy.resistFingerprinting:true. Are you seeing different behavior? What makes you think it's not RFP?

Are you seeing different behavior? What makes you think it's not RFP?

I was being lazy and making you do the testing :) Sorry, not sorry :) I see the same as you. Here are the console errors

• left: RFP is on with a canvas exception, force reload
• right: RFP is off

IDK why the code thinks the image is now too big to be supported? I see the waypoints, and can move around, there's just no imagery

(In reply to Simon Mainey from comment #7)

IDK why the code thinks the image is now too big to be supported?

Good catch! I should have looked more closely at the error messages. It looks like this is the result of the RFP analog (Bug 1217290) of "WebGL Minimal-Capabilities Mode" (Bug 686732) which defines the maximum texture size as 2048. See: https://hg.mozilla.org/mozilla-central/rev/61d074cfdeaf#l3.36

So this appears to be working as intended. Feel free to close or track as appropriate.

for the record, this can be reproduced as far back as FF60 (I didn't go back any further: just spot checked 78, 68, 60). Bug 967895 was added in FF58 and Bug 1217290 & Bug 1409677 were in FF57, I suspect it's one of the latter two

what timing, I was hunting thru the bugs trying to find the RFP webgl ones, you bet me to it

Great timing! Thanks again Simon.

For reference, now that we know what's going on, I opened an issue to let the site developer know: https://github.com/felixpalmer/peaks-of-austria/issues/1

Six years is a long time - https://bugzilla.mozilla.org/show_bug.cgi?id=1217290#c2 .. perhaps 2048 is too low these days for a minimum

[1] https://www.khronos.org/registry/webgl/specs/latest/1.0/
[2] https://www.khronos.org/registry/webgl/specs/latest/2.0/

We could probably update the constants here.