Study of a complex trogonometric plot - based on my dweet https://dwitter.net/d/23992

The basic code is just a variation of this:
for(i=0;i<W*H;i++)
for(Y=.3+(i/W)/29,X=(i%W)/29,j=i*4,K=C(X)-S(Y*C(X+Y))*C(t+X/Y)+t,o=1;o<4;++o)
image.data[j+o-1]=C(K*o)*(image.data[j+3]=255)

There are 8 palettes, some generate smooth patterns, others produce contours