display

#!/bin/bash
declare INTEL_FILE="/usr/share/X11/xorg.conf.d/20-intel.conf"
declare XORG_FILE="/usr/share/X11/xorg.conf.d/01-dummy-monitor.conf"

main() {
  case $1 in
    create)
      createDummyDisplayIntel ${@:2}
    ;;
    editIntel)
      editIntel
    ;;
    setRes)
      setRes ${@:2}
    ;;
    calcRes)
      calcRes ${@:2}
    ;;
    clean)
      clean ${@:2}
    ;;
    *)
      help
    ;;
  esac
}

createDummyDisplayIntel() {
  count=$1
  if [ -z "$count" ];then
    count=1
  fi
  if [ "$EUID" -ne 0 ]; then
    echo We may need sudo permissions to write the following file \"$INTEL_FILE\"
    echo
  fi
  sudo tee $INTEL_FILE > /dev/null <<TEXT
Section "Device"
    Identifier "intelgpu0"
    Driver "intel"
    Option "VirtualHeads" "$count"
EndSection
TEXT

 echo -e "Result\033[0;33m"
 cat $INTEL_FILE
 echo -e "\033[0m"
 echo Restart is needed to apply changes.
}

createDummyDisplayXorg() {
  count=$1
  if [ -z "$count" ];then
    count=1
  fi
  if [ "$EUID" -ne 0 ]; then
    echo We may need sudo permissions to write the following file \"$XORG_FILE\"
    echo
  fi
  sudo tee $XORG_FILE > /dev/null <<TEXT
Section "Device"
    Identifier  "Configured Video Device"
    Driver      "dummy"
EndSection
Section "Monitor"
    Identifier  "Configured Monitor"
    HorizSync 31.5-48.5
    VertRefresh 50-70
EndSection
Section "Screen"
    Identifier  "Default Screen"
    Monitor     "Configured Monitor"
    Device      "Configured Video Device"
    DefaultDepth 24
    SubSection "Display"
    Depth 24
    Modes "1024x800"
    EndSubSection
EndSection
TEXT

 echo -e "Result\033[0;33m"
 cat $XORG_FILE
 echo -e "\033[0m"
 echo Restart is needed to apply changes.
}

editIntel() {
  sudo vim $INTEL_FILE
} 
  
setRes() {
  virtual=$1
  width=$2
  height=$3
  modeline=$(cvt $width $height 20 | grep "Modeline" | cut -d' ' -f 2-17)
  modeName=$(echo $modeline | cut -d' ' -f 1)
  
  modeline=${modeline//\"}
  modeName=${modeName//\"}
  newModeName=$(echo $modeName | cut -d'_' -f1)
  modeline=${modeline/$modeName/$newModeName}
  modeName=$newModeName

  primary=$(xrandr| grep primary | cut -d ' ' -f 1)

  echo Creating \"$modeName\" on \"$virtual\"
  xrandr --newmode $modeline
  xrandr --addmode $virtual $modeName
  xrandr --output $virtual --mode $modeName --auto --right-of $primary
}

calcRes() {
  w_width=$1
  w_height=$2
  w_inches=$3

  f_xrandr=$(xrandr | grep primary)
  f_res=$(echo $f_xrandr | cut -d' ' -f 4)
  f_res=(${f_res//[+x]/ })
  f_dimens=$(echo $f_xrandr | cut -d' ' -f 13,15)
  f_dimens=(${f_dimens//m/})
  
  f_width=${f_res[0]}
  f_height=${f_res[1]}
  f_inches=$(bc <<< "scale=2; (sqrt( ${f_dimens[0]}^2 + ${f_dimens[1]}^2 ) * 0.0393701)/1")

  proportion=$(bc <<< "scale=4; $w_inches / $f_inches")

  v_width=$(bc <<< "scale=0; ($w_width * $proportion)/1")
  v_height=$(bc <<< "scale=0; ($w_height * $proportion)/1")

  rv_vert_width=$f_width
  rv_vert_height=$(bc <<< "scale=0; ($f_height + $v_height)/1")

  rv_hori_width=$(bc <<< "scale=0; ($f_width + $v_width)/1")
  rv_hori_height=$f_height

  echo Proportion $proportion
  echo "           Width x Height Inches"
  echo "   fisical  ${f_width}x${f_height} $f_inches"
  echo "    wanted  ${w_width}x${w_height} $w_inches"
  echo "----------------------------  Virtual"
  echo "   virtual  ${v_width}x${v_height}"
  echo "----------------------------  Resize + virtual"
  echo "  vertical  ${rv_vert_width}x${rv_vert_height}"
  echo "horizontal  ${rv_hori_width}x${rv_hori_height}"
}

clean() {
  display=VIRTUAL$1
  mode=$(xrandr | grep -A 1 $display | grep -Po "\d+x\d+")

  if [ -z "$mode" ]; then
    echo "Can't find a valid mode"
    exit 1
  fi
  
  echo "display $display"
  echo "   mode $mode"

  for m in $mode ; do
    echo "Try to remove $m"
    xrandr --output $display --off
    xrandr --delmode $display $m
    xrandr --rmmode $m
  done
  xrandr -s 0
}

help() {
cat <<TEXT
Virtual Display

Commands
 create <n>
  - creates n virtual displays
    example: $0 create 4

 setRes <display> <width> <height>
  - set resolution for a virtual display
    example: $0 setRes VIRTUAL1 800 600

 calcRes <width> <heigh> <inches>
  - calculate possible resolutions for a device.
    As devices may have same or  even greater resolutions compared to a normal display, de idea is to use a lower resolution for this device. This leads to a better visualization and performance.

 clean <virtual display number>
  - clean modes and resolution, also turns virtual display off
    example: $0 clean 1
TEXT
}
main $@