Detect OS window scaling without opening gfx window

[FeedTheCat]

Howdy folks,

has anyone found a way to detect OS window scaling without opening a gfx window? I'm looking for the return value of gfx.ext_retina.

For Gridbox, I am currently using a method that measures the tooltip window with JS_ReaScriptAPI, but turns out that this is unreliable.

[whats_up]

with windows api (js extentions) you can do it easly.
you can verify reaper main window,
or create a hidden window, verify and destroy

[FeedTheCat]

Originally Posted by whats_up

with windows api (js extentions) you can do it easly.
you can verify reaper main window,
or create a hidden window, verify and destroy

Hi whats_up, thank you for your response. I'm aware of the "create hidden window" method (it's plan B ).

Curious what you mean with "verify reaper main window"?

[whats_up]

find it by class name
and then verify its scaling

[Meo-Ada Mespotine]

reaper.ThemeLayout_GetLayout("tcp", -3)

returns the dpi currently used by Reaper. Just compare it with scaling factors.

Code I used to determine scalings from 1x to 8x is the following:

      local retval, dpi = reaper.ThemeLayout_GetLayout("tcp", -3)
      local dpi=tonumber(dpi)
      
      if dpi<384 then scale=1
      elseif dpi>=384 and dpi<512 then scale=1--.5
      elseif dpi>=512 and dpi<640 then scale=2
      elseif dpi>=640 and dpi<768 then scale=2--.5
      elseif dpi>=768 and dpi<896 then scale=3
      elseif dpi>=896 and dpi<1024 then scale=3--.5
      elseif dpi>=1024 and dpi<1152 then scale=4 
      elseif dpi>=1152 and dpi<1280 then scale=4--.5
      elseif dpi>=1280 and dpi<1408 then scale=5
      elseif dpi>=1408 and dpi<1536 then scale=5--.5
      elseif dpi>=1536 and dpi<1664 then scale=6
      elseif dpi>=1664 and dpi<1792 then scale=6--.5
      elseif dpi>=1792 and dpi<1920 then scale=7
      elseif dpi>=1920 and dpi<2048 then scale=7--.5
      else scale=8
      end

The variable scale returns the scaling factor.

It is compatible to retina-resolutions, afaik.
Scale=2 is Retina/HiDPI.

The benefit of the code above is, that it considers the scaling factor set by the user in the Prefs General->Advanced UI settings.

[FeedTheCat]

Originally Posted by Meo-Ada Mespotine

reaper.ThemeLayout_GetLayout("tcp", -3)

This is perfect!! Thank you!

Better than anything I was hoping for actually This gives me exactly what I was looking for, the scaling of the transport window:

local _, dpi = reaper.ThemeLayout_GetLayout('trans', -3)
transport_scale = tonumber(dpi) / 256