[Javascript] canvas操作

canvasを扱う備忘録

画像をcanvasタグで表示する

const img = new Image()
img.src = "%url"
img.onload = (e => {
  const img = e.target
  const canvas  = document.createElement("canvas")
  const ctx     = canvas.getContext("2d")
  const w       = img.naturalWidth
  const h       = img.naturalHeight
  canvas.width  = w
  canvas.height = h
  ctx.drawImage(img, 0, 0, w, h)
  return canvas
})