Function _isPointInArea

src/helpers/helpers.canvas.ts:317–326

(
  point: Point,
  area: TRBL,
  margin?: number
)

 * @private
 */
export function _isPointInArea(
  point: Point,
  area: TRBL,
  margin?: number
) {
  margin = margin || 0.5; // margin - default is to match rounded decimals

  return !area || (point && point.x > area.left - margin && point.x < area.right + margin &&
		point.y > area.top - margin && point.y < area.bottom + margin);
}

export function clipArea(ctx: CanvasRenderingContext2D, area: TRBL) {
  ctx.save();