curved-ruler on Nostr: Cassini ovals and Moiré See ...

Cassini ovals and Moiré
See https://mathstodon.xyz/@johncarlosbaez/113703444230936435 by nprofile1qy2hwumn8ghj7un9d3shjtnddaehgu3wwp6kyqpqknzsux7p6lzwzdedp3m8c3c92z0swzc0xyy5glvse58txj5e9ztqaufa4k (nprofile…fa4k)

vec3 col(in float x, in float y)
{
vec2 a = vec2(-15.0, 0.0);
vec2 b = vec2( 15.0, 0.0);
float da = sqrt( (x-a.x)*(x-a.x) + (y-a.y)*(y-a.y) );
float db = sqrt( (x-b.x)*(x-b.x) + (y-b.y)*(y-b.y) );
return isint(da*db/30.0, 0.1) ? vec3(0.9,0.55,0.0) : vec3(0.11);
}