It appears the GL canvas does not scale up with the rest of the UI. This happens on both Metal and GDK themes, so I suppose the theme itself isn't relevant. I'm using OpenJDK17 on Linux Mint 21.1. Here are the screenshots when values are GDK_SCALE=1, GDK_SCALE=2 and GDK_SCALE=4. As you can see, the canvas takes up 1/GDK_SCALE of the window's dimensions.
It appears the GL canvas does not scale up with the rest of the UI. This happens on both Metal and GDK themes, so I suppose the theme itself isn't relevant. I'm using OpenJDK17 on Linux Mint 21.1. Here are the screenshots when values are GDK_SCALE=1, GDK_SCALE=2 and GDK_SCALE=4. As you can see, the canvas takes up 1/GDK_SCALE of the window's dimensions.