Solaris X Window System Developer's Guide

Using Existing Xlib Pixel Transfer Routines

The Xlib pixel transfer routines XGetImage, XCopyArea, and XCopyPlane can also be used with transparent overlay windows.


On non-overlay drawables, the XGetImage routine works as defined in the X11 specification. The same is true for overlay windows, with the exception that, on these windows, the color information returned for transparent pixels is undefined. Clients who simply want to retrieve the display colors for a region on the screen should use XReadScreen.

XCopyArea and XCopyPlane

When both the source and destination drawables are non-overlay, the XCopyArea and XCopyPlane routines work as defined in the X11 specification. However, note the following for the cases in which either the source or the destination drawable is an overlay window.