Fixes Magic Arena's broken full screen implementation on macOS

arena-macos-full-screen-fixes.sh

#!/bin/bash

# this forces Arena into full screen mode on startup, set back to 3 to reset
# note that if you go into the Arena "Graphics" preference panel, it will reset all of these
# and you will need to run these commands again
defaults write com.wizards.mtga "Screenmanager Fullscreen mode" -integer 0
defaults write com.wizards.mtga "Screenmanager Resolution Use Native" -integer 0

# you can also replace the long complicated integer bit with any other scaled 16:9
# resolution your system supports.
# to find the scaled resolutions, go to System Preferences --> Display and then
# divide the width by 16 and multiple by 9. on my personal system this ends up
# as 3456 x 1944 (versus the bizarre 1728x1117 it will very temporarily select
# when clicking the full screen option in the client
defaults write com.wizards.mtga "Screenmanager Resolution Width" -integer \
  $(system_profiler SPDisplaysDataType | grep Resolution | cut -c23-26)
defaults write com.wizards.mtga "Screenmanager Resolution Height" -integer \
  $(bc <<< "$(system_profiler SPDisplaysDataType | grep Resolution | cut -c23-26) / 16 * 9")

The only solution that worked on my 14-inch MacBook Pro was to add the following command-line arguments to the Steam launcher:

-screen-width 3024 -screen-height 1701 -screen-fullscreen 0

After launching the game, press Cmd+F to toggle full-screen mode while preserving the correct aspect ratio (using -screen-fullscreen 1 or the green MacOS window button caused the aspect ratio to break for me).

For other display resolutions, you can calculate the appropriate screen-width and screen-height arguments using the formula provided in the original Gist:

# screen-width
echo "$(system_profiler SPDisplaysDataType | grep Resolution | cut -c23-26)"

# screen-height (maintains a 16:9 aspect ratio)
echo "$(bc <<< "$(system_profiler SPDisplaysDataType | grep Resolution | cut -c23-26) / 16 * 9")"