캠핑과 개발

HTML5의 canvas태그를 이용하여 생성된 객체 중력 예제입니다.





  1. <!DOCTYPE html>
  2. <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
  3. canvas {
  4.     border:1px solid #d3d3d3;
  5.     background-color: #f1f1f1;
  6. }
  7. </head>
  8. <body onload="startGame()">
  9.  
  10. var myGamePiece;
  11.  
  12. function startGame() {
  13.     myGamePiece = new component(30, 30, "red", 80, 75);
  14.     myGameArea.start();
  15. }
  16.  
  17. var myGameArea = {
  18.     canvas : document.createElement("canvas"),
  19.     start : function() {
  20.         this.canvas.width = 480;
  21.         this.canvas.height = 270;
  22.         this.context = this.canvas.getContext("2d");
  23.         document.body.insertBefore(this.canvas, document.body.childNodes[0]);
  24.         this.interval = setInterval(updateGameArea, 20);        
  25.     },
  26.     stop : function() {
  27.         clearInterval(this.interval);
  28.     },    
  29.     clear : function() {
  30.         this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
  31.     }
  32. }
  33.  
  34. function component(width, height, color, x, y, type) {
  35.     this.type = type;
  36.     this.width = width;
  37.     this.height = height;
  38.     this.x = x;
  39.     this.y = y;    
  40.     this.speedX = 0;
  41.     this.speedY = 0;    
  42.     this.gravity = 0.05;
  43.     this.gravitySpeed = 0;
  44.     this.update = function() {
  45.         ctx = myGameArea.context;
  46.         ctx.fillStyle = color;
  47.         ctx.fillRect(this.x, this.y, this.width, this.height);
  48.     }
  49.     this.newPos = function() {
  50.         this.gravitySpeed += this.gravity;
  51.         this.x += this.speedX;
  52.         this.y += this.speedY + this.gravitySpeed;
  53.         this.hitBottom();
  54.     }
  55.     this.hitBottom = function() {
  56.         var rockbottom = myGameArea.canvas.height - this.height;
  57.         if (this.y > rockbottom) {
  58.             this.y = rockbottom;
  59.         }
  60.     }
  61. }
  62.  
  63. function updateGameArea() {
  64.     myGameArea.clear();
  65.     myGamePiece.newPos();
  66.     myGamePiece.update();
  67. }
  68.  
  69.  
  70. <p>The red square will stop falling when it hits the floor.</p>
  71.  
  72. </body>
  73. </html>


출처 :

http://www.w3schools.com/games/game_gravity.asp