TRect

type TRect = object end;

  A: TPoint;

Top left corner of rectangle

  B: TPoint;

Bottom right corner of rectangle

  function Empty;

Is the surface of the rectangle zero

  function Equals();

Do the corners of the rectangles match

  function Contains();

Determine if a point is inside the rectangle

  procedure Copy();

Copy cornerpoints from another rectangle.

  procedure Union();

Enlarges rectangle to encompas another rectangle.

  procedure Intersect();

Reduce rectangle to intersection with another rectangle

  procedure Move();

Move rectangle along a vector.

  procedure Grow();

Expand rectangle with certain size.

  procedure Assign();

Set rectangle corners.

TRect

Describes a rectangular region in a plane.