waves.dc

80                const  WIDTH
24                const  HEIGHT
1 WIDTH /         const  INV_WIDTH
1 HEIGHT /        const  INV_HEIGHT
WIDTH HEIGHT *    const  AREA
HEIGHT    2  /    const  HIGHROW
WIDTH     2  /    const  HIGHCOL
HIGHROW  -1  *    const  LOWROW
HIGHCOL  -1  *    const  LOWCOL

var mybuf
AREA mkbuf
mybuf !

: bufadd
  over mybuf @ + swap 1 memset drop
;

: waves
  4096 times
    0
    HIGHROW LOWROW 1 for
      HIGHCOL LOWCOL 1 for
          i  INV_WIDTH * dup *    sin
            j INV_HEIGHT * dup *  cos
          * sqrt
            k
          *
          sin
            0.5
          <
          if 32 else 42 endif   bufadd
          1 +   # increment the original 0 counter
      next
    next
    mybuf @ AREA  +   0   1   memset drop
    mybuf @ print
    0.0384 sleep
    drop
  again
;

waves

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