ReadonlycontainsPoint: (r: PdfRect, x: number, y: number) => booleanTrue if (x, y) (page coordinates) lies within the rect, edges inclusive.
Readonlyheight: (r: PdfRect) => numberHeight of the rect (top - bottom, since the y-axis points up).
ReadonlyisEmpty: (r: PdfRect) => booleanTrue if the rect has non-positive width or height.
Readonlywidth: (r: PdfRect) => numberWidth of the rect (right - left).
Helper functions for PdfRect values (the coordinate system is y-up).