extension_method.js

CanvasRenderingContext2D.prototype.roundedRect = function (
  x,
  y,
  width,
  height,
  radius
) {
  this.save();
  this.translate(x, y);
  this.moveTo(width / 2, 0);
  this.arcTo(width, 0, width, height, Math.min(height / 2, radius));
  this.arcTo(width, height, 0, height, Math.min(width / 2, radius));
  this.arcTo(0, height, 0, 0, Math.min(height / 2, radius));
  this.arcTo(0, 0, radius, 0, Math.min(width / 2, radius));
  this.lineTo(width / 2, 0);
  this.restore();
};

CanvasRenderingContext2D.prototype.drawText = function drawText(
  font,
  text,
  x,
  y
) {
  if (text) {
    if (font) {
      this.font = font;
    }
    this.fillStyle = "black";
    this.fillText(text, x + 1, y + 1);
    this.fillStyle = "white";
    this.fillText(text, x, y);
  }
};