Lemniscate of Bernoulli

A lemniscate of Bernoulli.

0 = -2x² + x⁴ + 2y² + 2x²y² + y⁴

-2α² + α⁴ + 2β² + 2α²β² + β⁴

JSON: { "2,0": "-2", "4,0": "1", "0,2": "2", "2,2": "2", "0,4": "1" }

calc: -2*x^2 + x^4 + 2*y^2 + 2*x^2*y^2 + y^4

GLSL: -2.0*x*x+x*x*x*x+2.0*y*y+2.0*x*x*y*y+y*y*y*y