"Pixel-Perfect" icons still blurry at different display scales

[paulmcauley]

Icons are still blurry at different scales. E.g. 200%:

In Klassy I round the pen widths and then snap differently depending on whether it is an odd or even pen width -- odd pen width snap to half a pixel, even pen width snap to a whole pixel.
Klassy also has an elaborate (I would say actually overly-complicated) algorithm to draw the restore icon clearly. The actual "Material" icon set (i.e. from ChromiumOS) has a much simpler restore icon to draw.

[guiodic]

@paulmcauley
I'm trying your solution but it seems to make some buttons (keepbelow, keepabove, close) asimmetrical. Any suggestion?

edit: solved

[paulmcauley]

I don't know what you were doing wrong, but you don't need to snap non-vertical and non-horizontal lines as snapping will not make a visual difference to those.

[guiodic]

I don't know what you were doing wrong, but you don't need to snap non-vertical and non-horizontal lines as snapping will not make a visual difference to those.

Yes, I did it yesterday.

[guiodic]

@paulmcauley I also need 2 pen calculation, if I understand well. One phisically integer for hor/vert lines, the other one normal for other lines. If not, the diagonals are too fatty. You call them cosmetic and not cosmetic, if I understand.

[paulmcauley]

@paulmcauley I also need 2 pen calculation, if I understand well. One phisically integer for hor/vert lines, the other one normal for other lines. If not, the diagonals are too fatty. You call them cosmetic and not cosmetic, if I understand.

No, in Klassy I use the same pen width for both hor/vert and diagonal. I make them look similar by reducing the opacity of hor/vert slightly.

You have misunderstood cosmetic pens. A cosmetic pen is a Qt feature of the QPen whereby it is specified in device pixels and doesn't change with divicePixelRatio. A non-cosmetic pen scales with devicePixelRatio and you don't scale it manually. I wrote the Klassy icon functions so that it handles both Cosmetic and non-Cosmetic QPen settings, but if you are just using one type of QPen then you might not need to account for it.

[paulmcauley]

I think the thickness of the diagonals also depended on the snapping. For the close button I set the 4 corners of the close button to the maximize button shape.

[guiodic]

@paulmcauley can you test the master branch now?

[paulmcauley]

Yes, the snapping seems to be pixel-perfect at scale now.

The only thing is that restore icon is merged a bit at 100% scaling now

[guiodic]

The only thing is that restore icon is merged a bit at 100% scaling now

@paulmcauley

I don’t think so. Ok, it is compared to klassy, but it is intentional

[paulmcauley]

100% scaling:

At 200% scaling the squares aren't both squares:

[guiodic]

It works fine on my computer. Do you happen to have two screens with different scale factors?

[paulmcauley]

No, I am have only tested using one screen.

If you look at the 200% image I posted above it still isn't completely sharp either:

At 200% scaling the squares aren't both squares:

[guiodic]

What font, style and dimension you use for the titlebar? What is the screen resolution? I cant reproduce the problem...