Uploaded image for project: 'Qt'
  1. Qt
  2. QTBUG-71162

Layer-backed backingstore flush copies whole backingstore on each flush

XMLWordPrintable

    • macOS
    • 77a4915bf900aac0c96260018c0a4ccfbdd7c094 (qt/qtbase/5.12)
    • Bug Fixing Week Q2/2020

      Painting on a layer-backed window on macOS (which is apparently unavoidable now when building agains the 10.14 SDK?) performs poorly because of QImage::detach copying the image. This is related to QTBUG-63559. The commit message for that issue indicates that it isn't expected to be fixed for layer-backed windows.

      Is there any way to avoid the copy or disable the layer-backed backing store? I tried setting QT_MAC_WANTS_LAYER=0 without success.

        1. test.cpp
          0.7 kB
          Jason Haslam
        2. layer-backed.png
          199 kB
          Jason Haslam
        3. non-layer-backed.png
          245 kB
          Jason Haslam
        4. detach-in-flush.png
          225 kB
          Jason Haslam
        5. layer-backed-detach.diff
          1 kB
          Jason Haslam
        No reviews matched the request. Check your Options in the drop-down menu of this sections header.

            vestbo Tor Arne Vestbø
            jasonhaslam Jason Haslam
            Votes:
            1 Vote for this issue
            Watchers:
            8 Start watching this issue

              Created:
              Updated:
              Resolved:

                There are no open Gerrit changes