Radarbackground(0, 0, 0);
var angle = 0;
var draw = function() {
resetMatrix();
// draw a semi-transparent rectangle
// over the whole screen
fill(0, 0, 0, 10);
stroke(0, 0, 0);
rect(0, 0, 400, 400);
// move (0, 0) to the center of the canvas
// and rotate!
translate(200, 200);
rotate(angle);
// draw the circles
stroke(0,...