Inset-shadow on HTML5 canvas image

Question

I\'ve seen this question before but the answers given are for canvas images that have been drawn on via path however, i\'m drawing an image.

Is it possible to creat

Answer 1

const width = 100 * devicePixelRatio;
const height = 100 * devicePixelRatio;

// original canvas
const c = document.getElementById('canvas');
c.width = 300 * devicePixelRatio;
c.height = 300 * devicePixelRatio;
c.style.width = '300px';
c.style.height = '300px';
const cctx = c.getContext('2d');
cctx.fillStyle = 'rgb(20,205,75)';
cctx.arc(150 * devicePixelRatio, 150 * devicePixelRatio, 50 * devicePixelRatio, 0, Math.PI * 2);
cctx.fill();

// temporary canvas
const canvas = document.createElement('canvas');
canvas.width = width;
canvas.height = height;
canvas.style.width = `${width / devicePixelRatio}px`;
canvas.style.height = `${height / devicePixelRatio}px`;
document.body.appendChild(canvas);
var ctx = canvas.getContext('2d');

// original object on temporary canvas
ctx.arc(50 * devicePixelRatio, 50 * devicePixelRatio, 50 * devicePixelRatio, 0, Math.PI * 2);
ctx.fill();

// shadow cutting
ctx.globalCompositeOperation = 'xor';
ctx.arc(50 * devicePixelRatio, 50 * devicePixelRatio, 50 * devicePixelRatio, 0, Math.PI * 2);
ctx.fill();

// shadow props
ctx.shadowBlur = 50;
ctx.shadowOffsetX = 0;
ctx.shadowOffsetY = -25;
ctx.shadowColor = '#000';
ctx.arc(50 * devicePixelRatio, 50 * devicePixelRatio, 50 * devicePixelRatio, 0, Math.PI * 2);
ctx.fill();

// shadow color
ctx.globalCompositeOperation = 'source-in';
ctx.fillStyle = 'blue';
ctx.fillRect(0, 0, canvas.width, canvas.height);

// object cutting
ctx.globalCompositeOperation = 'destination-in';
ctx.arc(50 * devicePixelRatio, 50 * devicePixelRatio, 50 * devicePixelRatio, 0, Math.PI * 2);
ctx.fill();

// shadow opacity
cctx.globalAlpha = .4

// inserting shadow into original canvas
cctx.drawImage(canvas, 200, 200);

Colored shadow /w opacity