HTML Canvas Animation Ship Simulation
<!doctype html> <html> <head> <meta charset="utf-8"> <title>Ship Sim 2</title> <style> #canvas {/*from w w w. jav a 2 s . co m*/ background-color: #000000; } </style> </head> <body> <canvas id="canvas" width="400" height="400"></canvas> <aside>Press left and right arrow keys to rotate ship, up to add thrust.</aside> <script> class Ship { constructor() { this.x = 0; this.y = 0; this.width = 25; this.height = 20; this.rotation = 0; this.showFlame = false; } draw(context) { context.save(); context.translate(this.x, this.y); context.rotate(this.rotation); context.lineWidth = 1; context.strokeStyle = "#ffffff"; context.beginPath(); context.moveTo(10, 0); context.lineTo(-10, 10); context.lineTo(-5, 0); context.lineTo(-10, -10); context.lineTo(10, 0); context.stroke(); if (this.showFlame) { context.beginPath(); context.moveTo(-7.5, -5); context.lineTo(-15, 0); context.lineTo(-7.5, 5); context.stroke(); } context.restore(); } } window.onload = function () { var canvas = document.getElementById('canvas'), context = canvas.getContext('2d'), ship = new Ship(), vr = 0, vx = 0, vy = 0, thrust = 0; ship.x = canvas.width / 2; ship.y = canvas.height / 2; window.addEventListener('keydown', function (event) { switch (event.keyCode) { case 37: //left vr = -3; break; case 39: //right vr = 3; break; case 38: //up thrust = 0.05; ship.showFlame = true; break; } }, false); window.addEventListener('keyup', function () { vr = 0; thrust = 0; ship.showFlame = false; }, false); (function drawFrame () { window.requestAnimationFrame(drawFrame, canvas); context.clearRect(0, 0, canvas.width, canvas.height); ship.rotation += vr * Math.PI / 180; var angle = ship.rotation, //in radians ax = Math.cos(angle) * thrust, ay = Math.sin(angle) * thrust, left = 0, right = canvas.width, top = 0, bottom = canvas.height; vx += ax; vy += ay; ship.x += vx; ship.y += vy; //screen wrapping if (ship.x - ship.width / 2 > right) { ship.x = left - ship.width / 2; } else if (ship.x + ship.width / 2 < left) { ship.x = right + ship.width / 2; } if (ship.y - ship.height / 2 > bottom) { ship.y = top - ship.height / 2; } else if (ship.y < top - ship.height / 2) { ship.y = bottom + ship.height / 2; } ship.draw(context); }()); }; </script> </body> </html>