Image being clipped when copied to HTML canvas using drawImage

Question

I am writing a small snippet that allows a user to drag an image into a div container (dropzone) and then creates a canvas in that div and paints the image into the div. But

Answer 1

I have canvas width and heihgt set to 100% in css setting so:

canvas.width = canvas.offsetWidth;
canvas.height = canvas.offsetHeight;

in page load event do the trick