A simple way to write frame animation

Posted by dey.souvik007 on Fri, 27 Dec 2019 19:41:42 +0100

Everything is very simple, as long as the basic work is solid

The so-called industry is a pile of simple things

What's more, we can only start from the most basic, Iterative Construction of knowledge system??

First look at the picture:

 

2. The code is as follows:

<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>A simple way to write frame animation</title>
	<style>
			#c1{
				border: 1px solid;
			}
	</style>

	<script>
		
	 	window.onload = function(){
	 		var c1 = document.getElementById('c1')
	 		var ctx= c1.getContext('2d')
	 		var canvasWidth = ctx.canvas.width;
	 		var canvasHeigh = ctx.canvas.height;

	 		var img = new Image();
	 		img.onload = function(){
		 		var imgWidth = img.width;
		 		var imgHeight = img.height;
		 		var personWidth = imgWidth/4;
		 		var personHeight = imgHeight/4;
		 		var x0 = canvasWidth/2 - personWidth/2;
		 		var y0 = canvasHeigh/2 - personHeight/2;
		 		var timer =null;
		 		var index = 0;
		 		c1.onmouseover = function(){
		 			ctx.drawImage(img,0,0,personWidth,personHeight,x0,y0,personWidth,personHeight)	
		 			clearInterval(timer)
		 			timer = setInterval(function(){
		 				ctx.clearRect(0,0,canvasWidth,canvasHeigh);
		 			
		 				index++;
						ctx.drawImage(img,index*personWidth,0,personWidth,personHeight,x0,y0,personWidth,personHeight);
						if(index>=3){
							index = 0;
						}			 				
		 			},300)
		 		
		 		}	

		 		c1.onmouseout = function(){
		 			alert('sdf')
		 		
		 		}

		 		

	 		}
	 		img.src = "image/04.png"
	 	}

	</script>
</head>
<body>
	
	<canvas id="c1"  width="500" height="500"></canvas>

</body>
</html>

Effect:

 

Draw the villain in the middle of the canvas, and then, when the mouse moves in, start a timer to change the picture constantly

 

Remove and end the timer!