Set up a pen display

Map the tablet to an absolute drawing area, preserve its proportions, and use the stylus side button to move the pointer between monitors. Replace 1234:5678 with the vendor and product IDs reported for your tablet.

gnoblin.configure {
    input = {
        tablets = {
            ["1234:5678"] = {
                mapping = "absolute",
                keep_aspect = true,
            },
        },
        styluses = {
            ["default-1234:5678"] = {
                secondary_button_action = "switch-monitor",
            },
        },
    },
}

Absolute mapping ties pen position to the mapped display area. keep_aspect prevents circles from becoming ovals when the tablet and display have different shapes; it may leave unused space at one edge. The default- stylus entry applies to matching devices without a more specific serial-number mapping.

After reloading, check that the pen reaches the full display and that the secondary button changes the active monitor. If it selects the wrong display, check the device ID and monitor arrangement before changing the mapping.

See input configuration for tablet IDs and supported stylus actions.