Uploaded image for project: 'Qt'
  1. Qt
  2. QTBUG-87035

Incorrect high dpi settings on embedded (eglfs, linuxfb, possibly others)

    XMLWordPrintable

    Details

      Description

      We are seeing bogus device pixel ratio and QWindow sizes reported on embedded devices with eglfs.

      For example, instead of dpr 1 and 1920x1080 one gets dpr ~1.692 and 1134x638. This wrong on a platform with no windowing system and no scaling and high dpi concepts.

      The suspicion is that all platform plugins must get a change similar what was done for Android and Cocoa in https://codereview.qt-project.org/c/qt/qtbase/+/157174 , i.e. they must now override logicalBaseDpi() and return the same value as logicalDpi() in order to get a scale factor of 1. Otherwise the factor is logicalDpi() / QDpi(96, 96) which is never what one wants.

      At minimum eglfs and linuxfb must be fixed up, but this may affect any other platform plugins as well.

      Not sure about affected Qt versions, said patch is for 5.14 which is somewhat concerning...

        Attachments

        No reviews matched the request. Check your Options in the drop-down menu of this sections header.

          Activity

            People

            Assignee:
            qt.team.graphics.and.multimedia Qt Graphics Team Oslo
            Reporter:
            lagocs Laszlo Agocs
            Votes:
            0 Vote for this issue
            Watchers:
            3 Start watching this issue

              Dates

              Created:
              Updated:
              Resolved:

                Gerrit Reviews

                There are no open Gerrit changes