The QRectF class defines a finite rectangle in the plane using floating point precision.| doc.qt.io
The QPoint class defines a point in the plane using integer precision.| doc.qt.io
The QSize class defines the size of a two-dimensional object using integer point precision.| doc.qt.io
The QRect class defines a rectangle in the plane using integer precision.| doc.qt.io
The QPainter class performs low-level painting on widgets and other paint devices.| doc.qt.io