[Upstream Bug, unfixable] Pixels on canvas are misaligned

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porg
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Post by porg »

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Last edited by porg on Thu Jun 09, 2022 10:28 pm, edited 1 time in total.
porg
Posts: 554
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Re: [Blocker Bug] Selection border not aligned with pixel grid - Impossible to reliably tell which pixel selected

Post by porg »

@Joerg: Thanks for the updated images & infos in your post:

Image …43 and …44: ✅ Pixel content + Selection + rulers are all nicely aligned. Update: Further testing ongoing according to @Joerg.

Could you please also answer these questions:
1) What happens when zooming in/out with the given selections? Does the same content-pixel jump in out of the selection?
2) What happens when you extend the selections? Do the always stay aligned? Or does the offset start to accumulate only slowly?
Last edited by porg on Thu Jun 09, 2022 10:30 pm, edited 1 time in total.
Fotokunst
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Re: [Blocker Bug] Selection border not aligned with pixel grid - Impossible to reliably tell which pixel selected

Post by Fotokunst »

Porg
Please delete your comments to Pic 10.45 or Image 45.

I removed Bildschirmfoto 2022-06-08 um 10.45.jpg
That sreenshot was not usefull for testing.
Sorry for confusion.

I am still testing.

Soon here is my new report.
porg
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Re: [Blocker Bug] Selection border not aligned with pixel grid - Impossible to reliably tell which pixel selected

Post by porg »

@Joerg
I updated my comments with references to image 45 accordingly.
Curious on your test results.
Fotokunst
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Re: [Blocker Bug] Selection border not aligned with pixel grid - Impossible to reliably tell which pixel selected

Post by Fotokunst »

First test iMac 27inch, macOS 10.14.6 Mojave.
Graphicconverter completely new installed.

Bildschirmfoto_2022-06-10_um_10.32.jpg
Bildschirmfoto_2022-06-10_um_10.32.jpg (31.55 KiB) Viewed 840749 times
Click - Use Defaults.



Bildschirmfoto_2022-06-10_um_10.33.jpg
Bildschirmfoto_2022-06-10_um_10.33.jpg (22.42 KiB) Viewed 840749 times
I tested with - Shrink to fit screen.
You can change this setting.
For foto editing I prefer - Shrink to fit, constrain zoom-ratio screen.


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III) Please try what I did in my previous two videos: Make a screenshot of text with antialiasing (simply from a TextEdit window). Turn rulers on. Zoom in. Make a selection. Then zoom in/out smoothly via trackpad or with CMD +/-.
-----------
Sreenshot TextEdit -> open in GC




Bildschirmfoto_2022-06-10_um_10.35.jpg
Bildschirmfoto_2022-06-10_um_10.35.jpg (19.57 KiB) Viewed 840749 times
Zoom 5000%

Zooming in/out with CMD +/-, mouse wheel -> no issues.
All pixels , selections allways aligned.

Follow next post.

Joerg
Last edited by Fotokunst on Fri Jun 10, 2022 3:02 pm, edited 2 times in total.
Fotokunst
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Re: [Blocker Bug] Selection border not aligned with pixel grid - Impossible to reliably tell which pixel selected

Post by Fotokunst »

During zooming watching what happens.
After a lot of zooming in/out still no issues.
Then a new selection, screenshot.


bildschirmfoto_2022-06-10_um_10.37.jpg
bildschirmfoto_2022-06-10_um_10.37.jpg (14.29 KiB) Viewed 840749 times
Zoom 2000%



Bildschirmfoto_2022-06-10_um_10.38.jpg
Bildschirmfoto_2022-06-10_um_10.38.jpg (20.38 KiB) Viewed 840749 times
Zoom 2560% manual setting


--------------
1) What happens when zooming in/out with the given selections? Does the same content-pixel jump in out of the selection?
2) What happens when you extend the selections? Do the always stay aligned? Or does the offset start to accumulate only slowly?
--------

1) - NO jumping in out - The same content-pixel is allways on its place.
2) - NO its quick - Selection always aligned - Quick zooming in out.


Follow next post.

Joerg
Last edited by Fotokunst on Fri Jun 10, 2022 3:07 pm, edited 4 times in total.
Fotokunst
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Re: [Blocker Bug] Selection border not aligned with pixel grid - Impossible to reliably tell which pixel selected

Post by Fotokunst »

Next testing iMac 27inch, macOS 12.4.

Rechecking ->
Zooming in/out with CMD +/-, mouse wheel -> no issues.
All pixels , selections allways aligned.

During zooming watching what happens.
After a lot of zooming in/out still no issues.
Then a new selection, screenshot.



Bildschirmfoto_2022-06-09_um_15.40.jpg
Bildschirmfoto_2022-06-09_um_15.40.jpg (27.01 KiB) Viewed 840746 times
Zoom 5000%




Bildschirmfoto_2022-06-09_um_15.42.jpg
Bildschirmfoto_2022-06-09_um_15.42.jpg (22.69 KiB) Viewed 840746 times
Zoom 200%




--------------
1) What happens when zooming in/out with the given selections? Does the same content-pixel jump in out of the selection?
2) What happens when you extend the selections? Do the always stay aligned? Or does the offset start to accumulate only slowly?
--------

1) - NO jumping in out - The same content-pixel is allways on its place.
2) - NO its quick - Selection always aligned - Quick zooming in out.

Zooming in/out is quick.
New selection is where I want.
No pixel, selection jumping.

I always get the same positiv results.


End of testing.



Joerg
porg
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Re: [Blocker Bug] Selection border not aligned with pixel grid - Impossible to reliably tell which pixel selected

Post by porg »

@Joerg: 👍 Thanks for this intensive testing! Showing that GC on your OS and HW aligns pixels, selection-frame and ruler-markers just fine in all types of operation.

@forum_adm: 🙁 What I may experience here is just another example of the drivers for the NVIDIA GeForce GT 750M 2 GB in my MBP (Mid 2014) for macOS Big Sur having been implemented badly:

1) I have reported Rendering glitches only in specific apps Photos and Safari on MBP 15'' (Mid 2014) when dGPU active in macOS 11 Big Sur and other users there confirmed they were affected too. Luckily it happens not too often.

2) What I experience in GC may just be another occurrence of that badly done dGPU driver implementation.
porg
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Re: [Blocker Bug] Selection border not aligned with pixel grid - Impossible to reliably tell which pixel selected

Post by porg »

Whether running on iGPU or dGPU makes no difference 🙁
1. Shut down MacBookPro.
2. Disconnected external display.
3. Booted right into test user account.
4. Status: No user applications running. dGPU was not engaged since boot. Only running on iGPU.
5. Opened image in GC 👉 ❌ Sadly the same unaligned pixels as always.

Conclusions: Bug occurs regardless whether your graphics run on the iGPU (Intel Iris Pro) or the dGPU (NVIDIA GeForce GT 750M 2 GB


MacOS UI resolution makes no difference either 🙁
1. Open image in GC. Zoom in to 5000%. Make a selection. Pixel offset bug manifests as always for me.
2. System Preferences > Displays > Resolution > Scaled: I change them on the fly and observe
- Larger Text (looks like 1024 x 680)
- Default (looks like 1440 x 900)
- More Space (looks like 1920 x 1200)

Observation: Regardless which UI scaling I choose: 👉 ❌ The unalignment of the pixels remain.
- Interestingly the offset is proportionally the same! See yourself on the screenshots below.
- This to me indicated the bug is not in the scaling which occurs when to putting the content to the display (and performing the @1x or @2x or @3x or whatever scaling)
- But how the pixels in the image file are scaled for the zoom view of that window, rendered by Apple Core Image, Apple Quartz, you name it.


GC on same 15in MBP Internal Retina Display at different macOS UI resolutions.png
GC on same 15in MBP Internal Retina Display at different macOS UI resolutions.png (518.49 KiB) Viewed 840712 times
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Re: [Blocker Bug] Selection border not aligned with pixel grid - Impossible to reliably tell which pixel selected

Post by forum_adm »

I use myself the "Use more area" setting.

So, that looks really like an Apple driver issue.

But I have two idea.

1) Please check the options "Show pixel bounds".
ShowBounds.jpg
ShowBounds.jpg (255.72 KiB) Viewed 840710 times
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