nixos-config/pkgs/eyezoom.nix

{ pkgs, ... }:
pkgs.writeScript "eyezoom" ''
arg="$1"

set -- $(
  ${pkgs.xorg.xrandr}/bin/xrandr | 
    ${pkgs.gawk}/bin/awk -F "[x+ ]" '/primary/ { print $4" "$5" "$6" "$7 }'
  )

W="$1"
H="$2"
offx="$3"
offy="$4"

HFACTOR=10
WFACTOR=4

WIDEDIV=2

mouse="pointer:Logitech MX Vertical"
zoomsens=0.1
# calculated using this with x = x+1, y = y+1. works, not sure why...
# https://unix.stackexchange.com/questions/491531/how-to-avoid-mouse-cursor-jumping-while-using-xinput-coordinate-transformation-m
xpos=$(( offx + (W / 2) + 1 ))
ypos=$(( offy + (H / 2) + 1 ))
zoommatrix="$zoomsens 0 $(${pkgs.bc}/bin/bc -l <<< "(1-$zoomsens)*$xpos") 0 $zoomsens $(${pkgs.bc}/bin/bc -l <<< "(1-$zoomsens)*$ypos") 0 0 1"

case "$arg" in
  eye)
    ${pkgs.wmctrl}/bin/wmctrl -R ':ACTIVE:' -e 0,$offx,$(( offy - (H * HFACTOR / 2) + (H / 2) )),$W,$((H*HFACTOR))
    xinput set-prop "pointer:Logitech MX Vertical" "Coordinate Transformation Matrix" $zoommatrix
  ;;
  tiktok)
    ${pkgs.wmctrl}/bin/wmctrl -R ':ACTIVE:' -e 0,$(( offx - ((W/WFACTOR)/2) + (W/2))),$offy,$((W/WFACTOR)),$H
    xinput set-prop "pointer:Logitech MX Vertical" "Coordinate Transformation Matrix" 1 0 0 0 1 0 0 0 1
  ;;
  wide)
    ${pkgs.wmctrl}/bin/wmctrl -R ':ACTIVE:' -e 0,$offx,$(( offy - ((H / WIDEDIV) / 2) + (H / 2) )),$W,$((H/WIDEDIV))
    xinput set-prop "pointer:Logitech MX Vertical" "Coordinate Transformation Matrix" 1 0 0 0 1 0 0 0 1
  ;;
  *)
    ${pkgs.wmctrl}/bin/wmctrl -R ':ACTIVE:' -e 0,$offx,$offy,$W,$H
    xinput set-prop "pointer:Logitech MX Vertical" "Coordinate Transformation Matrix" 1 0 0 0 1 0 0 0 1
  ;;
esac
''