Sine Wave outta Circle
You can see how a sine wave can be generated from a circle.
Code
elem=document.querySelector(".example-container");
setCanvas(elem);
t=0;
t2=0;
function draw(){
clearCanvas();
points=[]
x=90+80*cos(t);
y=HEIGHT/2+80*sin(t);
new circle(90,HEIGHT/2,80,'#695fe6',0,'#fff',2);
new line(90,HEIGHT/2,x,y,'#fff',2);
new circle(x,y,5,'#695fe6',0.6,'#fff',1);
new line(90,y,x,y,'#695fe6',1);
new line(90,HEIGHT/2-80,90,HEIGHT/2+80,'#695fe6',1);
for(i=0;i<WIDTH-90;i++){
points.push([90+i,HEIGHT/2+80*sin(degToRad(i-t2))]);
}
new polygon(points,'#695fe6',0,'#695fe6',1,false);
t-=0.01;
t2+=radToDeg(0.01);
requestAnimationFrame(draw);
}
draw();