Random points in pie (SO)

HTML

<canvas id=canvas width=600 height=600></canvas>

CSS

body {background:#777}

JavaScript

var ctx = canvas.getContext('2d'),
    count = 1000, // number of random  points
    cx = 150,
    cy = 150,
    radius = 148;

    ctx.beginPath();
    ctx.moveTo(cx, cy);
    ctx.arc(0+canvas.width/2, 0+canvas.height/2, radius, 0, 2*Math.PI);
    ctx.closePath();
    ctx.fillStyle = '#00000';
    ctx.fill();

// create random points
	ctx.fillStyle = '#ffffff';

while(count) {
	// randomise x:y
    
    ctx.fillRect(x + canvas.width/2, y + canvas.height/2, 2, 2);
    count--;
}