Reaper 5.40 released on 2017-03-24 introduces initial support for HiDPI (High-DPI) modes via the beta theme oriented to the zoom of 200%. The feature was previously available in prerelease versions (5.34+) of Reaper, but was disabled in stable versions until 5.40.
To enable DPI-aware mode for Reaper, the following setting should be used:
Options → Preferences → General → Advanced UI/system settings → HiDPI mode (Windows 7+) → Aware (experimental)
To enable the new HiDPI (200%) theme, it should be installed by drag-and-dropping it to the main Reaper’s window and then selected via the menu:
Options → Themes → Default_5.0_hidpi
Note that there are still some issues with the HiDPI support and the theme: some GUI elements (e. g. some text and
± buttons in “MIDI take” windows) are still unscaled, and some are blurry (apparently upscaled from regular, non-HiDPI graphics) (e. g. buttons for changing horizontal and vertical scales in “MIDI take” windows). Also, draggable-line areas are currently too narrow (apparently inversely proportional to zoom), so it’s quite hard to start dragging.
Running DPI-aware and non-DPI-aware plugins side by side
Given that Reaper has built-in VST “bridges” implemented as separate executables for the purpose of bridging and sandboxing (
reaper_host64.exe), it’s now possible to run HiDPI-compatible (DPI-aware) plugins and HiDPI-incompatible plugins simultaneously in the same Reaper instance while having correct GUI size in all of them at the same time.
To achieve this, it’s enough to run HiDPI-compatible plugins in the “Native” mode (when the plugin runs in the same process as the DAW itself) and run HiDPI-incompatible plugins in a separate or a dedicated process (so they run via a VST host implemented as a separate executable, and Windows is able to apply DPI scaling to them).
The solution is not perfect since a crash of a non-bridged plugin would crash the entire DAW, but it should work fine for plugins that are stable enough in general.
Experimental built-in scaling
Reaper has also a setting for scaling its UI for a while:
Options → Preferences → General → Advanced UI/system settings → Scale UI elements of track/mixer panels, transport, etc, by.
But such scaling is unfortunately partial (e. g. toolbar, some text and virtual keyboard are not scaled at all) and buggy (some scaled elements are rendered incorrectly).
HiDPI support in other DAWs
As far as I know, the only high-grade DAWs for Windows (besides Reaper) that support scaling their UI in a usable way are currently:
- Image-Line FL Studio 12+ (scalable up to 400%, HiDPI mode is enabled by default, extra non-DPI-aware executables are provided for use with outdated plugins);
- PreSonus Studio One 3+ (HiDPI can be enabled in settings);
- Ableton Live (formally not DPI-aware and so blurry by default, but there is a setting for scaling up to 200%, though it has relatively too small text size and UI elements in general, so its usability is probably limited).
Steinberg Cubase, Cakewalk Sonar and Avid Pro Tools for Windows do not support HiDPI.
The latest Cubase 9 released on 2016-12-07 does not support HiDPI despite that the Steinberg’s previously released product — Dorico — already supports HiDPI (based on macOS-version screenshots — 1, 2). Steinberg’s officials say that Dorico’s GUI is based on Qt framework that handles HiDPI scaling transparently, while Cubase uses its own GUI engine.