Retrieves the position and ScissorRect information for the Panel that is currently being drawn.

When using the surface library (and, by extension, the draw library) inside of the PANEL:Paint function, the origin (The on-screen position of (0,0)) is automatically shifted to the top-left corner of the panel to make it easier to draw the panel's contents. Additionally, render.SetScissorRect is used to clip (or "mask") all drawn content to within the boundaries of the panel. This function returns the information used by the surface library about the current panel's origin and ScissorRect.