User:Joak/canvas1

<canvas id="c1" showsrc> function draw() {

c = document.getElementById("c1")

//console.log("c is",c)

 p = c.getContext("2d")
   x = window.innerWidth;
   y = window.innerHeight;
   var positionx = x / 2;
   var positiony= y / 2;

   if( r < 5){

if(r == 3){ upordown = -0.02; } if(r == 0){ upordown = +0.02; } r=r+upordown; } r = Math.max(r, 0); r = Math.min(r, 3); r2 = map_range(r,0,3,3,0); movement = 400*Math.sin(r); movement2 =400*Math.sin(r2);

   var number1 = p.createRadialGradient(positionx,positiony,movement2,positionx,positiony,movement);
	number1.addColorStop(0, '#000000');
 	number1.addColorStop(1, '#FFFFFF');
 	
 	p.fillStyle = number1;
 	p.clearRect(0,0,c.width,c.height);
 	p.fillRect(0,0,x,y);

} function map_range(value, low1, high1, low2, high2) {

   return low2 + (high2 - low2) * (value - low1) / (high1 - low1);

}

</canvas>