|
|
| (One intermediate revision by the same user not shown) |
| Line 1: |
Line 1: |
| <!DOCTYPE html>
| |
| <html>
| |
| <head>
| |
| <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
| |
| <style>
| |
| canvas {
| |
| border:1px solid #d3d3d3;
| |
| background-color: #f1f1f1;
| |
| }
| |
| </style>
| |
| </head>
| |
| <body onload="startGame()">
| |
| <script>
| |
|
| |
|
| var myGamePiece;
| |
| var myObstacles = [];
| |
| var myScore;
| |
|
| |
| function startGame() {
| |
| myGamePiece = new component(30, 30, "red", 10, 120);
| |
| myGamePiece.gravity = 0.05;
| |
| myScore = new component("30px", "Consolas", "black", 280, 40, "text");
| |
| myGameArea.start();
| |
| }
| |
|
| |
| var myGameArea = {
| |
| canvas : document.createElement("canvas"),
| |
| start : function() {
| |
| this.canvas.width = 480;
| |
| this.canvas.height = 270;
| |
| this.context = this.canvas.getContext("2d");
| |
| document.body.insertBefore(this.canvas, document.body.childNodes[0]);
| |
| this.frameNo = 0;
| |
| this.interval = setInterval(updateGameArea, 20);
| |
| },
| |
| clear : function() {
| |
| this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
| |
| }
| |
| }
| |
|
| |
| function component(width, height, color, x, y, type) {
| |
| this.type = type;
| |
| this.score = 0;
| |
| this.width = width;
| |
| this.height = height;
| |
| this.speedX = 0;
| |
| this.speedY = 0;
| |
| this.x = x;
| |
| this.y = y;
| |
| this.gravity = 0;
| |
| this.gravitySpeed = 0;
| |
| this.update = function() {
| |
| ctx = myGameArea.context;
| |
| if (this.type == "text") {
| |
| ctx.font = this.width + " " + this.height;
| |
| ctx.fillStyle = color;
| |
| ctx.fillText(this.text, this.x, this.y);
| |
| } else {
| |
| ctx.fillStyle = color;
| |
| ctx.fillRect(this.x, this.y, this.width, this.height);
| |
| }
| |
| }
| |
| this.newPos = function() {
| |
| this.gravitySpeed += this.gravity;
| |
| this.x += this.speedX;
| |
| this.y += this.speedY + this.gravitySpeed;
| |
| this.hitBottom();
| |
| }
| |
| this.hitBottom = function() {
| |
| var rockbottom = myGameArea.canvas.height - this.height;
| |
| if (this.y > rockbottom) {
| |
| this.y = rockbottom;
| |
| this.gravitySpeed = 0;
| |
| }
| |
| }
| |
| this.crashWith = function(otherobj) {
| |
| var myleft = this.x;
| |
| var myright = this.x + (this.width);
| |
| var mytop = this.y;
| |
| var mybottom = this.y + (this.height);
| |
| var otherleft = otherobj.x;
| |
| var otherright = otherobj.x + (otherobj.width);
| |
| var othertop = otherobj.y;
| |
| var otherbottom = otherobj.y + (otherobj.height);
| |
| var crash = true;
| |
| if ((mybottom < othertop) || (mytop > otherbottom) || (myright < otherleft) || (myleft > otherright)) {
| |
| crash = false;
| |
| }
| |
| return crash;
| |
| }
| |
| }
| |
|
| |
| function updateGameArea() {
| |
| var x, height, gap, minHeight, maxHeight, minGap, maxGap;
| |
| for (i = 0; i < myObstacles.length; i += 1) {
| |
| if (myGamePiece.crashWith(myObstacles[i])) {
| |
| return;
| |
| }
| |
| }
| |
| myGameArea.clear();
| |
| myGameArea.frameNo += 1;
| |
| if (myGameArea.frameNo == 1 || everyinterval(150)) {
| |
| x = myGameArea.canvas.width;
| |
| minHeight = 20;
| |
| maxHeight = 200;
| |
| height = Math.floor(Math.random()*(maxHeight-minHeight+1)+minHeight);
| |
| minGap = 50;
| |
| maxGap = 200;
| |
| gap = Math.floor(Math.random()*(maxGap-minGap+1)+minGap);
| |
| myObstacles.push(new component(10, height, "green", x, 0));
| |
| myObstacles.push(new component(10, x - height - gap, "green", x, height + gap));
| |
| }
| |
| for (i = 0; i < myObstacles.length; i += 1) {
| |
| myObstacles[i].x += -1;
| |
| myObstacles[i].update();
| |
| }
| |
| myScore.text="SCORE: " + myGameArea.frameNo;
| |
| myScore.update();
| |
| myGamePiece.newPos();
| |
| myGamePiece.update();
| |
| }
| |
|
| |
| function everyinterval(n) {
| |
| if ((myGameArea.frameNo / n) % 1 == 0) {return true;}
| |
| return false;
| |
| }
| |
|
| |
| function accelerate(n) {
| |
| myGamePiece.gravity = n;
| |
| }
| |
| </script>
| |
| <br>
| |
| <button onmousedown="accelerate(-0.2)" onmouseup="accelerate(0.05)">ACCELERATE</button>
| |
| <p>Use the ACCELERATE button to stay in the air</p>
| |
| <p>How long can you stay alive?</p>
| |
| </body>
| |
| </html>
| |
