JSFiddle - React, Tailwind, and code Playground

by Vijay Gujar

HTML

<button id="clockwise">Rotate right</button>
<button id="counterclockwise">Rotate left</button>

CSS

body{ background-color: ivory; }
canvas{border:1px solid red;}

JavaScript

var canvas;

var angleInDegrees=0;

var image=document.createElement("img");
image.onload=function(){
    
    drawRotated(0);
}
image.src="http://greekgear.files.wordpress.com/2011/07/bob-barker.jpg";

$("#clockwise").click(function(){ 
    angleInDegrees+=90 % 360;
    drawRotated(angleInDegrees);
});

$("#counterclockwise").click(function(){ 
    if(angleInDegrees == 0)
        angleInDegrees = 270;
    else
        angleInDegrees-=90;
    drawRotated(angleInDegrees);
});

function drawRotated(degrees){
    if(canvas) document.body.removeChild(canvas);
    
    canvas = document.createElement("canvas");
    var ctx=canvas.getContext("2d");
    canvas.style.width="20%";
    canvas.width = image.width;
  	canvas.height = image.height;
    /* if(degrees == 90 || degrees == 270) {
        canvas.width = image.height;
        canvas.height = image.width;
    } else {
        canvas.width = image.width;
        canvas.height = image.height;
    } */
    
    ctx.clearRect(0,0,canvas.width,canvas.height);
    if(degrees == 90 || degrees == 270) {
		ctx.translate(canvas.height/2,canvas.width/2);
    } else {
	    ctx.translate(image.width/2,image.height/2);
   }
    ctx.rotate(degrees*Math.PI/180);
    ctx.drawImage(image,-canvas.width/2,-canvas.height/2, canvas.width, canvas.height);
    
    document.body.appendChild(canvas);
}