// fall // // spiral draws at 2^(-n) paper 100 pen 0 set c 5 set bound 4 number exp a b { set result 1 repeat k 1 b { set result (result*a) } value result } command pawz n { repeat i 0 n { } } command points p0 q0 p q color { repeat i p0 p { repeat j q0 q { set [i j] color pawz (<exp 2 (color/c)>) } } } command drawpts x0 y0 { set x x0 set y y0 repeat n 0 (100/c) { set x0 x set y0 y same? 0 (n % 4) { set y (y0+c*n) } same? 1 (n % 4) { set x (x0+c*n) } same? 2 (n % 4) { set y (y0-c*n) } same? 3 (n % 4) { set x (x0-c*n) } points x0 y0 x y (c*n) } } drawpts 50 50