Size of screen diagonal?

[Peter Reid]

I'm developing a desktop app for Mac & PC that displays photos of coins. I'd like to display them at real size but I can't find the properties for the current screen (i.e. the one that my app is running on.  I can get the screen colour depth, resolution, scaling factor, etc. but not the physical size on the screen such as "27 inch diagonal" or physical px per inch.

Can anyone tell me how to get this info, either using just LiveCode or via Mac/PC shell/command scripts?

Thanks

Pete
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Peter Reid
Loughborough, UK