aoc2022/d10/part2.awk

function inc() {
	i = (c++%40)  # inc c after
	printf "%s", (i==x||i==x+1||i==x+2) ? "█" : " "
	if (i == 39) { print "" }
}
{ inc() }
$1 == "addx" {
	inc()
	x+=$2
}