gradient.thump

pi $0, si 0
pi $1, si 1
pi $2, si 2
pi $4, si 4
pi $8, si 8
pi $16, si 16
pi $127, si 127
pi $shifter, pi 0
pi $roffset, pi 0
pi $goffset, pi 0
pi $boffset, pi 0

@mainloop
pi $x, si 0
@xloop
pi $sinv, s $x, add $shifter, mul $2
pi $yoffset, sin $sinv, div $8
pi $y, si 0
@yloop
pi $r, s $y, add $roffset, div $16, mul $16, add $127
pi $g, s $y, sub $goffset, div $16, mul $2
pi $b, s $y, sub $boffset, div $16, mul $4
pi $realy, s $y, add $yoffset
x $x, y $realy, zi 4, s $r
x $x, y $realy, zi 5, s $g
x $x, y $realy, zi 6, s $b
pi $y, add $1, seq $0, j @yloop
pi $x, add $1, seq $0, j @xloop

pi $shifter, add $1
w $1
j @mainloop