JSFiddle - React, Tailwind, and code Playground

by confile

HTML

<div id="container"></div>
<script src="https://dl.dropboxusercontent.com/u/47067729/konva.min.js"></script>Strength
<input id="strength" type="range" value="40" min="0" max="80" step="1" />
<spam id="strengthValue"></spam>
<br>Opacity
<input id="opacity" type="range" value="0.5" min="0" max="1" step="0.001" />
<spam id="opacityValue"></spam>
<br><div id="undo">Undo</div><br>
    
    <canvas id="c2"></canvas>

CSS

#container {
    border: 1px solid green;
    background-color: lime;
}

JavaScript

console.clear();

var history = new Array();

var imageObj = new Image();
var img = null;
var offsetX = 0;
var offsetY = 0;
var degrees = 45;

stage = new Konva.Stage({
    container: 'container',
    width: 600,
    height: 400
});
layer = new Konva.Layer();
stage.add(layer);

var rect = new Konva.Rect({
      x: 30,
      y: 30,
      width: 438,
      height: 300,
      fill: 'yellow'
    });
layer.add(rect);

var canvas = document.createElement('canvas');
var context = canvas.getContext('2d');


var content = self.stage.getContent();
content.addEventListener("touchmove", function () {
    console.log("content touchmove");
}, false);
content.addEventListener("touchend", function () {
    console.log("content touchend");
}, false);


var circle = new Konva.Circle({
    x: 0,
    y: 0,
    radius: 40,
    opacity: 0.7,
    fill: '#ff5e0a',
    stroke: '#d95009',
    strokeWidth: 1,
    draggable: true
});
layer.add(circle);


circle.on('dragmove touchmove', function (e) {
 //   console.log("x:" + e.evt.clientX + " y:" + e.evt.clientY);
    erase(e.evt.clientX, e.evt.clientY, circle.radius(), img.x(), img.y());
});

circle.on('dragend', function (e) {
    console.log("dragend");
    addToHistory();
});

imageObj.onload = function () {
    canvas.width = imageObj.width;
    canvas.height = imageObj.height;
    context.drawImage(imageObj, 0, 0, imageObj.width, imageObj.height);

    var imgX = 30;
    var imgY = 30;
    
    // save the image
    addToHistory();
    
    img = new Konva.Image({
        x: imgX,
        y: imgY,
        image: canvas
    });
   // img.stroke('blue');
   // img.strokeWidth(5);
   // img.scaleX(0.4);
   // img.scaleY(0.4);

    img.setRotation(degrees);
    
    offsetX = imageObj.width / 2;
    offsetY = imageObj.height / 2;
    
    var rotationX = imgX + offsetX;
    var rotationY = imgY + offsetY;
    
    img.setOffsetX(offsetX);
    img.setOffsetY(offsetY);
    img.x(rotationX);
    img.y(rotationY);
    
   ...