Pixel preview position bug?

[anweid]

[for Affinity Designer 1.5.0.24]

 

1. Create a new document with a small pixel size (e.g., 48px width and 32px height).

2. Switch to pixel preview.

3. Draw an ellipse, beginning at the (more or less) exact left top of the document (this works

    with 'magnets' switched to full pixels or not).

4. The pixelated circle probably will NOT start at the left  top of the document, but somehow shifted.

5. Using the mouse wheel, zoom to different levels: Depending on the zoom level, the position

    of the pixelated circle inside the document changes seemingly randomly by around two pixels.

    Note that these are not screen pixels, but DOCUMENT pixels.

6. See the attached screenshots showing the SAME document containing an ellipse (with

    left=0.5px, top=0.5px, width=32px, height=25px, linewidth=1px) on different zoom levels:

    Left 460.6% (the circle shows up inside the document), right 398.7% (the circle seems to

    start OUTSIDE the document).

7. The same effect is visible when switching on the grid: The origin of the grid shifts random-like

    at +-1 document pixels depending on the current zoom level.

 

Andreas Weidner

   

[Sean P]

Hi Andreas,

I've just tried this myself and i'm unable to see the kind of jumping that is shown in your screenshots.

Would you be able to attach the document that is showing this. I've attached mine if you want to give that a go.

Thanks

SmallDocument.afdesign

[MEB]

Hi Sean P,

This was already logged for the Mac version some time ago.

You have to create an artboard to see the mismatch (and have pixel preview enabled).

[anweid]

After MEB's reply I thought this problem would be solved in a newer version, so I didn't bother answering. Unfortunately, the problem still exists in version 1.5.2.58 (German, under a German 64-bit Windows 7), so let me be a bit more specific:

• @ Sean P: The problem does persist even in your 'SmallDocument'. Probably I didn't describe the problem well, so you didn't know what to look for.
• @ MEB: An artboard does not need to be created, but it also persists when using artboards.
• Attached is an Affinity document and a screenshot, please view these for reference. The document has a size of 20x20 pixels and no artboard, but an ellipse with 1 pixel inside outline that exactly matches the document pixels.
• The mentioned problem is not a bad jumping, but a mismatch between grid/pixels and the document area, which depends on the current zoom level and absolute position on screen.
• Viewing the ellipse in split view, one sees that everything looks perfect in the vector view (even the right of the ellipse - which cannot be seen here - is perfectly aligned). In the pixel view though, the ellipse is again perfectly rendered at the same screen position as the vector view, but the document borders are not: Here, by some reason the document height appears to be larger, and the right document border does not seem to extend to the right of the ellipse (though it does in vector view).
• Therefore, this is not really a problem of the rendering of the graphics objects, but of the document area itself. Unfortunately, when placing objects on this document area without visible pixel grid, this nearly always results in graphics objects that are misaligned by one pixel, making later adjustments necessary.
• Since this mismatch is not larger than one document pixel, it only matters for documents that are pixel-based, relatively small and viewed with a zoom which makes one document pixel larger than a screen pixel. Unfortunately, this is often the case when designing GUI bitmaps.

Andreas Weidner

ellipse.afdesign

[MEB]

Hi anweid,

We are aware of this issue. It's already logged and assigned but wasn't fixed yet.