Hi all,I want to tell you, what I have found so far, so that if someone will actually fix the problem, can use this information.
The problem: If someone has a higher resolution screen and therefore uses an OS scaling of e.g. 150%, the markers for resizing and rotation, the anchor and the crop markers are broken.
What happens:LO generates larger images and stores them in cache/<icontheme name>/<scaling factor>. For 150% you get a file markers.png of size 175x138 instead of the original 117x92. But the method, which crops the desired marker out of the markers.png uses rectangles which assume 117x92. Therefore the wrong parts of marker.png are used. Proof: Exchange the enlarged markers.png with the original and the markers are drawn correctly. But they are too small for a high resolution screen.
In https://opengrok.libreoffice.org/xref/core/svx/source/svdraw/svdhdl.cxx#742 is the method BitmapEx ImpGetBitmapEx(BitmapMarkerKind eKindOfMarker, BitmapColorIndex eIndex) According comment, it is designed for HiDPI. It uses single markers, with names of structure svx/res/marker-rect9-6.png and similar. Such files are contained in the image-themes in core, but not in the image-themes in the zip-files, which are delivered. Therefore ImpGetBitmapEx uses the old method with one combined markers.png file as fallback. Proof: If you pack an image-theme from core and add it to your installation, the single enlarged marker is generated and used.
For cropmarkers.png such single files are not used. Here you get the enlarged file with size 229x94 instead of the original size 153x63 for my 150% example and therefore really ugly handles.
Why do the delivered icon-themes do not contain the single markers? That would at least solve the problem for markers until a more general fix is available.
Kind regards Regina