JSFiddle - React, Tailwind, and code Playground
HTML
<div id="container"></div>
<script src="https://cdn.rawgit.com/konvajs/konva/2.3.0/konva.min.js"></script>
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: 50,
y: 50,
width: 438,
height: 300,
fill: 'yellow'
});
layer.add(rect);
var canvas = document.createElement('canvas');
var context = canvas.getContext('2d');
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) {
draw(e.evt.clientX, e.evt.clientY, circle.radius(), img.x(), img.y());
});
imageObj.onload = function () {
canvas.width = imageObj.width;
canvas.height = imageObj.height;
context.drawImage(imageObj, 0, 0, imageObj.width, imageObj.height);
var imgX = 50;
var imgY = 50;
img = new Konva.Image({
x: imgX,
y: imgY,
image: canvas
});
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);
context.translate(canvas.width/2, canvas.height/2);
context.rotate(-degrees * Math.PI/180);
layer.add(img);
circle.moveToTop();
layer.draw();
};
imageObj.src = "https://www.trackpro.co.uk/img/stage.png";
function draw(absX, absY, radius, imageX, imageY) {
var x = 0;
var y = 0;
// set pointer
circle.x(absX);
circle.y(absY);
// imageX = imageX - (offsetX);
// imageY = imageY - (offsetY);
x = absX - imageX;
y = absY - imageY;
// translate context to center of canvas
// ...