2 Argument Arctangent
A simple implementation of atan2(y,x) function of ChelseaJS.
It looks like two eyes following the mouse.
Code
elem=document.querySelector(".example-container");
setCanvas(elem);
t=0;
fetch_mouse_pos(elem,'mousemove');
function draw(){
clearCanvas()
new circle(WIDTH/3,HEIGHT/2,100,'#fff',1);
theta=atan2(HEIGHT/2-mousepos.y,mousepos.x-WIDTH/3);
x1=WIDTH/3+50*cos(theta);
y1=HEIGHT/2-50*sin(theta);
new circle(2*WIDTH/3,HEIGHT/3,60,'#fff',1);
theta2=atan2(HEIGHT/3-mousepos.y,mousepos.x-2*WIDTH/3);
x2=2*WIDTH/3+30*cos(theta2);
y2=HEIGHT/3-30*sin(theta2);
new circle(x2,y2,30,'#222',1);
new circle(x1,y1,50,'#222',1);
requestAnimationFrame(draw);
}
draw();