Testing on an AMD64 running Kubuntu 16.04, using wish:

% tk scaling
1.3333333333333333

Testing on the same PC using undroidwish:

% tk scaling
1.0006771314250538

As a result, content on undroidwish looks smaller when using density dependent units.

Works as designed and was documentent about 3 years ago, see [427535dec3571d4d8afb52c0d0ae6c20e7835afa]

It seems I forgot to RTFM. Thanks!

More on this issue:
<br><br>
My goal is to present an sdltk window on a desktop PC that accurately emulates the screen of a mobile phone/tablet device. To achieve this I do the following:
<ol>
<li>Write down the target device's densitydpi and density, as returned by the command `borg displaymetrics` run on androwish on the mobile device. An example of such result from an actual device is: `densitydpi 240 density 1.5`</li>
<li>On the PC, run `undroidwish -sdlxdpi <densitydpi>`, where <densitydpi> is the value returned by the above `borg displaymetrics` command.</li>
<li>Inside undroidwish, run the following code:</li>
<code><pre>
% tk scaling
3.344855967078189
# set `tk scaling` to the <density> value return by `borg displaymetrics`
% tk scaling 1.5
# create a shape with specs dependent on device dpi:
% pack [frame .f -width 20m -height 20m -bg red] -padx 20m -pady 20m 
<pre><code>
<li>Measure the red rectangular representing the specified tk frame widget. Result: It measures exactly the specified 20mm.</li>
</ol>
So I conclude that this method gives an adequate solution to the set goal. Now the problem:
<br><br>
While tk seems to be correctly set to display the content, the sdltk window borders are scaled by the -sdlxdpi value given at the command line, which seems to be approx. 240.0/72 = 3.333.., in the above example. <a href='https://github.com/dzach/awemu/blob/master/issues/sdltk_border.png'>See this screenshot</a>. The size of the font in the console is not a problem; it will resize properly once the console is redrawn by Tk. But...
<br><br>
I have not found a way to set sdltk's window borders. Tk commands for toplevel windows do not seem to influence sdltk's window decoration in undroidwish. I can make them disappear, e.g. by running `wm overrideredirect`, but then the ability to move the windows around is lost. 
<br><br>
How can one change window decoration sizes in sdltk? It seems they should be tied to the `tk scaling` that undroidwish comes up with initially.

There are some hard coded steps in which the window manager decorations
are adapted to the dpi ratio of the screen. This was needed especially
on Android devices which have a great bandwidth of dpis (140 ... 550).

There's certainly room for improvement but I have no time for it. If you'd
like to contribute a patch, I'll gladly integrate it.

What would be a location to start looking?

[b65fa01ff47e67b9ff62e3e404ee97fbdf3397f9]

[6586a4973f3eebf82fb9487f2221554a5f0a48c3]

search for "dpi" and "dec_frame_height"