NegativeScreen has been interacting badly with Chrome's hardware acceleration, for some time, in my experience

[mlaily]

Originally reported by: Jason Spiro (Bitbucket: jasonspiro, GitHub: jasonspiro)

---

Hi! First I'll describe the problem; then I'll describe what I have; then I'll mention the workarounds which I've found; then I'll ask you some questions.

The problem.

When NegativeScreen is running and active, and my Chrome window is maximized, NegativeScreen works in a buggy way. It successfully inverts the taskbar and Chrome's tab bar, but has trouble inverting webpages. They blink back and forth between inverted and not inverted. When the right-click menu is open, webpages are successfully inverted, but when the menu is closed, they're often not inverted at all.

The bug didn't always happen. It started some time ago. I don't know what caused it; maybe it was some automatic software update.

What I've been using.

• NegativeScreen: version 2.4 (64-bit).
• OS: Windows 10 Home 1607 (10.0.14393.187). This was released September 13, 2016; 6 days ago.
• Web browser: Google Chrome 53.0.2785.116 (32-bit) (Stable channel). This was released September 14, 2016; 5 days ago.
• System: an Acer Aspire E5-511-P8C8 laptop.
• Integrated graphics processor: "Intel HD Graphics 4600 for 4th Generation Intel Core Processors".
• Graphics driver: 10.18.10.4276 (8/16/2015). This is a driver that Windows 10 has given me. It's about a year older than Intel's newest available driver.

The workarounds I've found.

I've found four different workarounds. You don't need to do all four; doing just one will be sufficient. In the end, I chose to stick with the first workaround.

1. Chrome has a checkbox labeled "Use hardware acceleration when available". Uncheck the box. (As Chrome will tell you, your settings change won't take effect until after you restart Chrome.) (Note: Disabling hardware acceleration may also stop some or all WebGL programs from working.)
2. Or unmaximize the Chrome window.
3. Or stop using NegativeScreen, and use Magnifier's color-inversion feature instead.
4. Or (this is an odd workaround):
   • Start Magnifier.
   • Set it to 100% zoom (no magnification). Leave it running (with its color inversion off) while NegativeScreen is running (with its color inversion on).

My questions.

A) How many people use NegativeScreen?

B) Does this bug affect everyone who uses the same OS and browser versions as me, or is it hardware-dependent?

---

• Bitbucket: https://bitbucket.org/yaurthek/negativescreen/issue/4

[mlaily]

Original comment by Melvyn Laïly (Bitbucket: yaurthek, GitHub: Unknown):

---

Hi, thanks for your nicely formatted bug report :)

You are the first one to report the behavior you are experiencing, and unfortunately, I could not reproduce it on three different computers with a very similar configuration (same OS and browser, one Intel HD 520, one HD 4000, and one Nvidia GTX 970).

The bug only appearing recently probably either means some software got updated, or your hardware is failing.

Your 3rd and 4th workarounds are very odd. NegativeScreen is supposed to use the same API as the Windows Magnifier, so I would expect the Magnifier to display the same behavior as NegativeScreen...

I'll look into it.

To answer your questions:
A) I don't know, there is no tracker in the application.
B) As I said above, it looks like it's hardware dependent, or at least driver dependent.

[mlaily]

Original comment by Jason Spiro (Bitbucket: jasonspiro, GitHub: jasonspiro):

---

Thanks for the compliment :)

I'm not sure how recently the bug started happening. I started using NegativeScreen again only recently, after a very long hiatus. Maybe a hiatus of months. As soon as I started using NegativeScreen again, I started to experience the bug for the first time.

I don't actually need Chrome hardware acceleration at all. I can live without it, forever. I don't need WebGL

If I'm the first person to report this bug, and if not too many people use NegativeScreen (say, if less than 10,000 people download it per year), then I don't think it's worth fixing. We can just leave the bug open forever, unfixed.

[mlaily]

Original comment by Melvyn Laïly (Bitbucket: yaurthek, GitHub: Unknown):

---

It's less a question about the number of people downloading NegativeScreen, and more a question of whether I can fix it in the first place!
As I said, most of the actual color transformation work is done by the Magnification API, so I'm not sure I can do much.

If you are satisfied with the workaround you found, great, but it's still annoying, and I'll try to look into it.

[manujdhariwal]

I am facing the same issue with Google Chrome, will try the said solutions and give an update ..... thanks!

[jasonspiro]

@manujdhariwal: Thanks for commenting!

A) Does the exact same issue happen on all your Windows machines?

B) What version of Windows is running?

C) Do you know what graphics hardware is inside the affected machines?

[manujdhariwal]

I just use one machine.
Windows Version 10.0.14393
Intel HD Graphics 520
Processor: Intel(R) Core(TM) i7-6500U CPU @ 2.50GHz, 2 Core(s)
After disabling hardware acceleration as was suggested in the solution above, the problem resolved!
So currently if I switch on the hardware acceleration I turn off negativescreen and vice-versa ....

thanks,

[jasonspiro]

@manujdhariwal: I'm glad that this workaround helped!

Why would you ever want Chrome hardware acceleration on?

[jasonspiro]

The same bug also affects Simplenote 1.0.8 for Windows, which is open-source software.

Simplenote for Windows is built upon the Electron framework, which is built upon Chromium.

Chromium is closely related to Google Chrome.