Shared Whiteboard

Two independent drawing desks share one board over a virtual serial cable. Each peer keeps its own ink, cursor and status while remote strokes appear in the same canvas.

Run it

Build examples with devenv shell -- lcom-ng-build, then:

lcom-ng run-pair build/examples/serial_whiteboard left \
  --right build/examples/serial_whiteboard right

Controls

• Mouse drag: draw. 1-5: ink. Shift+arrows: draw with the keyboard.
• G: grid. C: clear both boards. S: resync. R: reconnect. F1: help.

In the app

Two desks, one boardBoth peers connect over the virtual serial cable.

Draw togetherEach board shows both local and remote strokes.

The other side of the conversationThe right desk keeps its own ink and cursor while sharing the same board.

A clear canvasG hides the guide grid without changing any strokes.

Resynchronize the drawingS replays the local stroke snapshot to the other desk.

Draw from the keyboardShift + arrow keys draws precise segments, arrows alone move the cursor.

A shared surface, familiar controlsF1 explains drawing, colors, clearing and resynchronization.

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Two desks, one board · Both peers connect over the virtual serial cable.

What it demonstrates

UART framing, sequence numbers, reconnect and resync, PS/2 input, local ownership and shared rendering. Both windows must stay open.

Source: examples/serial_whiteboard.c.

Refresh captures with the screenshot workflow.