circles

"burst { pushdict
  "cy swap def "cx swap def "size swap def
  dup
  6.28 swap /
  "step swap def
  dup
  {
    "cx @ "cy @ dM
    dup
    "step @ *
    dup
    cos "size @ * swap sin "size @ * dl
    1 -
    dup
  } while
  drop
  popdict
} subprog def

15 50 100 rand 0.5 - 20 * + 100 rand 0.5 - 20 * + "burst @ call
15 50 130 rand 0.5 - 20 * + 130 rand 0.5 - 20 * + "burst @ call
15 50 130 rand 0.5 - 20 * + 100 rand 0.5 - 20 * + "burst @ call
15 50 100 rand 0.5 - 20 * + 130 rand 0.5 - 20 * + "burst @ call

6 6 dup {
  dup
  dup
  rot
  swap
  {
    "y swap def swap "x swap def
    "x @ "y @ + 3 +
    50
    "x @ 30 * 250 + "y @ 30 * 50 +
    "burst @ call
    "x @ swap "y @
    1 -
    dup
  } while
  drop
  swap
  1 -
  dup
  rot
  swap
} while
drop

path
stop