The QPaintEngineState class provides information about the active paint engine's current state.| doc.qt.io
Information about the coordinate system used by the paint system.| doc.qt.io
The QPaintEngine class provides an abstract definition of how QPainter draws to a given device on a given platform.| doc.qt.io
The QPaintDevice class is the base class of objects that can be painted on with QPainter.| doc.qt.io