Canvas solar system
/*
<canvas id="canvas" width="300" height="300"></canvas>
*/
var sun = new Image();
var moon = new Image();
var earth = new Image();
function init() {
sun.src = '../images/Canvas_sun.png';
moon.src = '../images/Canvas_moon.png';
earth.src = '../images/Canvas_earth.png';
window.requestAnimationFrame(draw);
}
function draw() {
var ctx = document.getElementById('canvas').getContext('2d');
ctx.globalCompositeOperation = 'destination-over';
ctx.clearRect(0, 0, 300, 300); // clear canvas
ctx.fillStyle = 'rgba(0, 0, 0, 0.4)';
ctx.strokeStyle = 'rgba(0, 153, 255, 0.4)';
ctx.save();
ctx.translate(150, 150);
// Earth
var time = new Date();
ctx.rotate(((2 * Math.PI) / 60) * time.getSeconds() + ((2 * Math.PI) / 60000) * time.getMilliseconds());
ctx.translate(105, 0);
ctx.fillRect(0, -12, 50, 24); // Shadow
ctx.drawImage(earth, -12, -12);
// Moon
ctx.save();
ctx.rotate(((2 * Math.PI) / 6) * time.getSeconds() + ((2 * Math.PI) / 6000) * time.getMilliseconds());
ctx.translate(0, 28.5);
ctx.drawImage(moon, -3.5, -3.5);
ctx.restore();
ctx.restore();
ctx.beginPath();
ctx.arc(150, 150, 105, 0, Math.PI * 2, false); // Earth orbit
ctx.stroke();
ctx.drawImage(sun, 0, 0, 300, 300);
window.requestAnimationFrame(draw);
}
init();
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