Hi All,
The HDPI display handling of ARCHICAD 20 and previous versions are different on MAC and WIN. The Windows and Macintosh operating systems support HDPI displays on different ways.
On windows ARCHICAD uses the Win 32 API which gives only a basic HDPI development support, so development needs to occur to use HDPI. (On MAC this was a smaller effort.)
(Background info: Every application either does or does not specify how it runs on an HDPI display. The ones which do not specify DPI support are the 'Non DPI aware' applications. Without scaling, the HDPI display shows the windows of these applications extremely small because the pixel size is significantly smaller than on a normal display. To keep readability Windows scales up the UI of these applications: the window content is rendered by the application on a normal way and then Windows scales up the window image with a bitmap stretch. The scaling factor is dependent on the system settings. This scaling causes some blurriness, that is why the UI of ARCHICAD 20 looks blurry this way.)
The solution to this problem is that the scaling should be performed by the application itself and not by Windows. ARCHICAD needs to create bigger dialogs with bigger fonts and dialog elements.
This is an important priority for GRAPHISOFT and development has been initiated to support HDPI displays. It is planned for an upcoming version of ARCHICAD.
If you would like some more information, please read this article about how Win 32 works with HDPI displays:
https://msdn.microsoft.com/en-us/library/windows/desktop/dn469266%28v=vs.85%29.aspx
To avoid blurriness, the scaling can be disabled in the application property dialog, but this causes everything to be very small.
