Canvas scale is wrong when Windows resolution scaling is used

[andrechalella]

I have two monitors. The main one (4k, landscape) has 175% zoom applied to it in Windows monitor resolution settings. The secondary one (Full HD, portrait) has no zoom applied to it (that is, 100%).

 

Monitor 1 config in Windows.

 

Monitor 2 config in Windows.

 

In such setup, Paint.NET viewport (canvas) does not use 1 pixel to display 1 pixel. As you can see in the image below, the viewport is much smaller than the window, even with the canvas resolution equal to the screen resolution (1200x1920). You can see that Paint.NET zoom is 100%.

 

Problem: Paint.NET canvas smaller than it should be.

 

Zoom problems wouldn't be unexpected in Monitor 1, which has 175% zoom as I said before. However, this is in Monitor 2, which does not have zoom/scaling applied. As such, it is impossible to use Paint.NET accurately in Monitor 2.

 

More information:

 

• Analyzing the attached image, it's easy to see that Paint.NET is using 686 pixels to represent the width of 1200 pixels. That is, 1.75 times less, which matches the zoom level of Monitor 1 (175%).
• In Monitor 1, everything works fine. That is, one pixel is displayed in one pixel when Paint.NET zoom is 100% (again, Windows monitor zoom is set to 175%).

 

What was expected: that Paint.NET canvas would always use 1 pixel to represent 1 image pixel, regardless of Windows monitor zoom.