;circle routine, by Foxy
;uses square root function
{ "$1" GREPSUB ATOI radius = radius DUP * sq =
MOUSEPOS cy = cx = radius x = 0 y = radius 30 / 1 + step =
{ x oldx = y oldy =
step x -= sq x x * - SQUAREROOT y =  1 dir =
{ dir odir = dir =
cx oldx dir * + cy oldy odir * + cx x dir * + cy y odir * + LINE
cx oldy dir * + cy oldx odir * + cx y dir * + cy x odir * + LINE
} [ 1 -1 -1 1 ] FOREACH
} { x y > } WHILE
} CHATSTR "^drawcircle (.*)$" GREPSTR IF