JQ Texture Atlas Grouper

atlas_group.jq

def intersects(a;b): any(a[]; . as $x | any(b[]; . == $x));

def mapatlas(set):
(set | unique) as $unique_set
| (map(if intersects(.; $unique_set) then . else empty end) | add + $unique_set | unique) as $new_set
| map(if intersects(.; $new_set) then empty else . end) + [$new_set];

reduce .[] as $entry ([]; mapatlas($entry))
# | to_entries | .[]? | select(any(.value[]; . == "red")) | .key

#[
#  ["red", "black", "orange"],
#  ["coral", "green", "blue"],
#  ["zzz", "qqq", "xxx"],
#  ["7", "qqq", "blue"]
#]