.dual-monitor

#!/bin/bash
set -e

# Default mutable values. Change it if you need
WIDTH=1280
HEIGHT=800
REFRESH=60
PRIMARY_OUTPUT=LVDS-1
VIRTUAL_OUTPUT=VGA-1

# Default immutable values. Don't touch it!
CREATE=false
ENABLE=false
DISABLE=false

# Get custom initial parameters
while getopts "cdeh:p:r:v:w:" option; do
    case "${option}" in
        c) CREATE=true;;
        d) DISABLE=true;;
        e) ENABLE=true;;
        h) HEIGHT=${OPTARG};;
        p) PRIMARY_OUTPUT=${OPTARG};;
        r) REFRESH=${OPTARG};;
        v) VIRTUAL_OUTPUT=${OPTARG};;
        w) WIDTH=${OPTARG};;
    esac
done

NAME="${WIDTH}x${HEIGHT}"

if [ ${CREATE} == true ]; then
    echo "Creating a virtual display..."
    # Extract and output generated modeline parameters
    MODELINE="$(gtf ${WIDTH} ${HEIGHT} ${REFRESH} \
                  | sed -n 's/.*Modeline ".\+"  \(.*\)/\1/p')"
    printf "
        Name: ${NAME}
        Primary output: ${PRIMARY_OUTPUT}
        Virtual output: ${VIRTUAL_OUTPUT}
        Modeline: ${MODELINE}\n\n"
    # Generate new mode based on the modeline
    echo "[1/3] - Creating a mode with modeline args"
    xrandr --newmode "${NAME}" ${MODELINE}
    # Add the desired mode to our disconnected output
    echo "[2/3] - Adding the mode to the output"
    xrandr --addmode "${VIRTUAL_OUTPUT}" "${NAME}"
    # Enable the virtual monitor using the newly added mode
    echo "[3/3] - Enabling the newly created mode"
    xrandr --output "${VIRTUAL_OUTPUT}" \
           --mode "${NAME}" \
           --right-of "${PRIMARY_OUTPUT}"
    echo "Successfully created!"
elif [ ${DISABLE} == true ]; then
    echo "Disabling the virtual output..."
    # Disconnect the output to be able to delete a mode if any
    echo "[1/3] - Disconnecting the output"
    xrandr --output "${VIRTUAL_OUTPUT}" --off
    # Deleting the mode of the disconnected output
    echo "[2/3] - Deleting the output mode"
    xrandr --delmode "${VIRTUAL_OUTPUT}" "${NAME}" || :
    # Deleting the display port which was using by the mode
    echo "[3/3] - Deleting the display port"
    xrandr --rmmode "${NAME}" || :
    echo "Successfully disabled!"
elif [ ${ENABLE} == true ]; then
    echo "Starting the VNC server..."
    HOST_IP="$(hostname -I | head -n1 | awk '{print $1;}')"
    x11vnc -listen "${HOST_IP}" \
           -clip "xinerama1" \
           -nocursorpos \
           -nocursorshape
else
    printf "
    PRIMARY COMMANDS (without args):
    -c – create a mode for a virtual output
    -e – enable a mode of a virtual output
    -d – disable a mode of a virtual output

    CONFIGURATION:
    -h – height of a virtual screen
         default '800'
         used with the '-c' and '-d' flags
    -p – primary output name
         default 'LVDS-1'
         used with the '-c' flag
    -r – refresh frequency of a virtual screen
         default '60'
         used with the '-c' flag
    -v – virtual output name
         default 'VGA-1'
         used with the '-c' and '-d' flags
    -w – width of a virtual screen
         default '1280'
         used with the '-c' and '-d' flags\n\n"
fi