2D Wave Equation

Choose your own adventure (write a Javascript equation using x and y, they range from 0 to pi)
(x >= Math.PI/5 && x <= Math.PI*2/5 && y >= Math.PI/5 && y <= Math.PI*2/5) ? Math.sin(5*x)*Math.sin(5*y) : (x >= Math.PI*3/5 && x <= Math.PI*4/5 && y >= Math.PI*3/5 && y <= Math.PI*4/5) ? Math.sin(5*x)*Math.sin(5*y) : 0
Set
FPS: