rect
The size and position of the clipping area, in device-independent pixels.
The clipRect is transformed by the current transform set on the surface.
After the transform is applied to the clipRect that is passed in, the axis-aligned bounding box for the clipRect is computed. For efficiency, the contents are clipped to this axis-aligned bounding box and not to the original clipRect that is passed in.
A PushClip and PopClip pair can occur around or within a PushLayer and PopLayer, but cannot overlap.