kaleidoscope.dc

# run this in an 80x24 terminal
#
# usage:   nice -19 dclang kaleidoscope.dc

# buffer size is 1921 (1920, but 1 extra slot for null character)
var mybuf
1921 mkbuf
mybuf !

# characters to choose from, right now, set to ' ' and '*'
32 1 !
42 2 !
32 3 !

: bufadd
  over mybuf @ + swap 1 memset drop
;

: kaleidoscope
  4096 times
    0                           # buffer offset, local on the stack
    24 times
      80 times
        i  160 / 0.25 - dup *   # This is all distance formula stuff:
        j  48 / 0.25 - dup *    # sqrt(a^2 + b^2)...distance from origin
        + sqrt sin              # (sine of the distance from origin)
        k 0.5 * * cos 0.5 * 0.51 + 2.9 * floor
        1 + @ bufadd
        1 +                     # increment the buffer offset
      again
    again
    # add null char on buffer end
    mybuf @ 1920 + 0 1 memset drop
    # print the buffer
    mybuf @ print
    0.0384 sleep
    drop
  again
;

kaleidoscope

cr
"DONE!!!!!!" print
cr