ViewPortAddress

Return the address of a window's viewport.

Returns the address of the viewport associated with the specified window. The viewport is actually the viewport of the screen within which the window is displayed. If you want to use any of the graphics, text, or animation primitives in your window and that primitive requires a pointer to a viewport, you can use this call.

This pointer is only valid as long as your window's screen remains open, which is ensured by keeping your window open.

Window

pointer to the window for which you want the viewport address

Returns the address of the Intuition ViewPort structure for your window's screen .

This routine is unnecessary: you can just use the expression &Window->WScreen->ViewPort.

graphics.library