Recursion challenge

[Antoni Gual]

With recursion you can draw a tree

Code:

DECLARE SUB tree (x%, y%, a!, l!, o%)
CONST right = 3.1415926# / 2
CONST dec1 = .9, dec2 = .2, dec3 = .77
CONST inc1 = .2, inc2 = .3, inc3 = .98
RANDOMIZE TIMER
SCREEN 12: WINDOW (240, 320)-(-239, -319)

DO
CLS
tree (0), (-200), (0), 70, 10
t! = TIMER + 1: DO: LOOP UNTIL TIMER > t!
LOOP UNTIL LEN(INKEY$)

SUB tree (x%, y%, a, l, o%)
STATIC temp, temp1
IF o% THEN
  PSET (x%, y%)
  temp = (RND - .5) * dec3
  temp1 = (RND - .5) * inc3
  x% = x% + l * COS(a + temp1 + right) + temp
  y% = y% + l * SIN(a + temp1 + right) + temp
  LINE -(x%, y%)
  tree (x%), (y%), (a + inc1), l * dec1, o% - 1
  PSET (x%, y%)
  tree (x%), (y%), (a - inc1), l * dec1, o% - 1
END IF
END SUB

..or create a maze.