vincentbernat.i3wm-configuration/bin/picom-configure

#!/bin/sh -e

dpi=$(xrdb -query | sed -nE 's/^Xft\.dpi:\s*//p')

POLYBAR_HEIGHT=$((20 * dpi / 96))
SHADOW_RADIUS=$((12 * dpi / 96))
SHADOW_OFFSET=$((SHADOW_RADIUS*2/3))

# Configure picom
cat ~/.config/i3/dotfiles/picom.conf \
    | sed -e "s/@POLYBAR_HEIGHT@/$POLYBAR_HEIGHT/" \
    | sed -e "s/@SHADOW_RADIUS@/$SHADOW_RADIUS/" \
    | sed -e "s/@SHADOW_OFFSET@/$SHADOW_OFFSET/" \
          > $XDG_RUNTIME_DIR/i3/picom.conf.new

# Put new configuration file in place
cmp $XDG_RUNTIME_DIR/i3/picom.conf.new $XDG_RUNTIME_DIR/i3/picom.conf 2> /dev/null || \
    mv $XDG_RUNTIME_DIR/i3/picom.conf.new $XDG_RUNTIME_DIR/i3/picom.conf