HTML5 Game - Canvas Animation Animation Controller

Create your own animation controller class

The HTML5 canvas API doesn't define methods for animation.

The following code create our own animation class for handling an animation stage.

<!DOCTYPE HTML> 
<html>
    <head>
        <script>
class MyAnimation {
   constructor(canvasId){
        this.canvas = document.getElementById(canvasId);
        this.context = this.canvas.getContext("2d");
        this.t = 0;
        this.timeInterval = 0;
        this.startTime = 0;
        this.lastTime = 0;
        this.frame = 0;
        this.animating = false;
        
        window.requestAnimFrame = (function(callback){
            return window.requestAnimationFrame ||
            window.webkitRequestAnimationFrame ||
            window.mozRequestAnimationFrame ||
            window.oRequestAnimationFrame ||
            window.msRequestAnimationFrame ||
            function(callback){
                window.setTimeout(callback, 1000 / 60);
            };
        })();
   }
   getContext(){
      return this.context;
   };

   getCanvas(){
      return this.canvas;
   };

   clear(){
       this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
   };

   setDrawStage(func){
       this.drawStage = func;
   };

   isAnimating = function(){
       return this.animating;
   };

   getFrame(){
      return this.frame;
   };

   start(){
        this.animating = true; 
        let date = new Date();
        this.startTime = date.getTime();
        this.lastTime = this.startTime;
        
        if (this.drawStage !== undefined) {
            this.drawStage();
        }
        
        this.animationLoop();
   };

   stop(){
       this.animating = false;
   };

   getTimeInterval(){
       return this.timeInterval;
   };

   getTime(){
    return this.t;
   };

   getFps(){
      return this.timeInterval > 0 ? 1000 / this.timeInterval : 0;
   };

   animationLoop(){
        let that = this;
        
        this.frame++;
        let date = new Date();
        let thisTime = date.getTime();
        this.timeInterval = thisTime - this.lastTime;
        this.t += this.timeInterval;
        this.lastTime = thisTime;
        
        if (this.drawStage !== undefined) {
            this.drawStage();
        }
        
        if (this.animating) {
            requestAnimFrame(function(){
                that.animationLoop();
            });
        }
    }   
}         
        </script>
        <script>
            window.onload = function(){
                let anim = new Animation("myCanvas");
                 
                anim.setDrawStage(function(){
                   
                });
                anim.start();
            };
        </script>
    </head>
    <body>
        <canvas id="myCanvas" width="600" height="250" style="border:1px solid black;">
        </canvas>
    </body>
</html>

Note

A typical FPS value for a smooth animation is somewhere between 40 and 60 frames per second.

HTML5 Game - Canvas Animation Animation Controller

Create your own animation controller class

Note

Related Topics