Screen

Screen

The Screen tab of the Manager is where the player's screen is described and set: what the player has, what Glass suggests from it, and the three settings the display reads. It matters most on a screen with no X server, where Glass draws through the kernel's KMS/DRM directly and turns the picture itself; under X the server does the turning and the tab says so.

What the player has

When the tab opens the Manager reads the kernel and the system and says what it found, in plain words:

• Panels: every connector the kernel knows, connected or not, with its native size; a panel taller than wide is named portrait by nature, which many small DSI and DPI panels are.
• Touch, mice, keyboards: the input devices by what they are. An HDMI remote arrives as a pointing device and is named as a remote, not a mouse.
• Backlight: each backlight with its brightness and its greatest.
• The screen: whether the kiosk holds it, whether the Touch Display or the Display Configuration plugin is on, and whether an X server is running.

Look again reads it all afresh, after a mouse is plugged in or a plugin turned off.

From what it found the Manager suggests a rotation and a pointer: a portrait panel suggests the angle the Touch Display plugin has on file, or 270 when it has none, the way the common panels are mounted; a mouse suggests the pointer shown, a touch panel alone suggests it hidden.

The settings

Setting	Values	What it does
Drawn by	Auto, X, Wayland, the screen itself (KMS/DRM)	What draws the display's window. Auto takes X when the kiosk runs one, else the screen itself.
Rotation	0, 90, 180, 270	The picture and touch turned clockwise on a screen no X server turns; the same angle the Touch Display plugin uses. With X the server turns the screen and this stays 0.
Pointer	Auto, Shown, Hidden	Whether the pointer is drawn on the player's window. Auto shows it with a mouse and hides it with a touch panel alone, resolved from what the player has at every save and at every start.

The display starts again with a change. KMS/DRM cannot be chosen while the kiosk holds the screen: two owners of it fight, so the Touch Display plugin goes off first, and comes back on the way out.

The keys, in the display's configuration: screen.driver, screen.rotation, screen.pointer (the choice) and screen.pointer.shown (what the plugin resolved). The Manager-API page has the routes.

A screen with no X server

With the driver on KMS/DRM the device shows Glass alone: no X server and no kiosk browser on the device, which on a Raspberry Pi 5 with the same theme and music means about 300 MB less in use, every browser process gone, and the display's own cost unchanged. The picture is drawn in the panel's own orientation and turned by the rotation; touch is turned the same way. GLASS_GRAB=/path.png in the display's environment writes the picture as shown, after the first frames, so a screen can be checked from a terminal.

The Troubleshooting page has the cases: a portrait, cropped picture; KMS/DRM refused; nothing shown.