XCOMPOSITE(3) | libXcomposite | XCOMPOSITE(3) |
NAME¶
Xcomposite - X Composite Extension librarySYNOPSIS¶
#include <X11/extensions/Xcomposite.h>
Bool
XCompositeQueryExtension(Display *dpy,
int *event_base_return,
int *error_base_return);
Status
XCompositeQueryVersion(Display *dpy,
int *major_version_return,
int *minor_version_return);
int
XCompositeVersion(void);
void
XCompositeRedirectWindow(Display *dpy,
Window window, int update);
void
XCompositeRedirectSubwindows(Display *dpy,
Window window, int update);
void
XCompositeUnredirectWindow(Display *dpy,
Window window, int update);
void
XCompositeUnredirectSubwindows(Display *dpy,
Window window, int update);
XserverRegion
XCompositeCreateRegionFromBorderClip(Display *dpy,
Window window);
Pixmap
XCompositeNameWindowPixmap(Display *dpy,
Window window);
Window
XCompositeGetOverlayWindow(Display *dpy,
Window window);
void
XCompositeReleaseOverlayWindow(Display *dpy,
Window window);
DESCRIPTION¶
The composite extension provides several related mechanisms: Per-hierarchy storageThe rendering of an entire hierarchy of
windows is redirected to off-screen storage. The pixels of that hierarchy are
available whenever it is viewable. Storage is automatically reallocated when
the top level window changes size. Contents beyond the geometry of the top
window are not preserved.
Automatic shadow update
When a hierarchy is rendered off-screen, the X
server provides an automatic mechanism for presenting those contents within
the parent window. The implementation is free to make this update lag behind
actual rendering operations by an unspecified amount of time. This automatic
update mechanism may be disabled so that the parent window contents can be
completely determined by an external application.
Composite Overlay Window
Version 0.3 of the protocol adds the Composite
Overlay Window, which provides compositing managers with a surface on which to
draw without interference. This window is always above normal windows and is
always below the screen saver window. It is an InputOutput window whose width
and height are the screen dimensions. Its visual is the root visual and its
border width is zero. Attempts to redirect it using the composite extension
are ignored. This window does not appear in the reply of the QueryTree
request. It is also an override redirect window. These last two features make
it invisible to window managers and other X11 clients. The only way to access
the XID of this window is via the CompositeGetOverlayWindow request.
Initially, the Composite Overlay Window is unmapped.
Parent window clipping
Version 0.4 of the protocol modifies the
semantics of parent window clipping in the presence of manual redirected
children. With this version, the area in the parent covered by manual
redirected children is left in the parent clip list instead of being removed
as in older versions.
Per-hierarchy storage may be created for individual windows or for all children
of a window. Manual shadow update may be selected by only a single application
for each window; manual update may also be selected on a per-window basis or
for each child of a window. Detecting when to update may be done with the
Damage extension.
The off-screen storage includes the window contents, its borders and the
contents of all descendants.
ARGUMENTS¶
displayPointer to the Display structure
returned from XOpenDisplay for the connection to the X server.
event_base_return
Pointer to integer where the base value for
Composite Extension events will be stored.
error_base_return
Pointer to integer where the base value for
Composite Extension errors will be stored.
major_version_return
Pointer to integer where the major version of
the Composite Extension supported by the X server will be stored.
minor_version_return
Pointer to integer where the minor version of
the Composite Extension supported by the X server will be stored.
window
Specifies the window ID to operate on.
update
Specifies the mode for updating the window
contents. Must be either CompositeRedirectAutomatic or
CompositeRedirectManual.
FUNCTIONS¶
XCompositeQueryExtensionThis request specifies that the client is no
longer using the Composite Overlay Window on the screen specified by the
argument window. A screen's Composite Overlay Window is unmapped when
there are no longer any clients using it.
The X server must support at least version 0.3 of the Composite Extension for
XCompositeReleaseOverlayWindow.
AUTHORS¶
Keith Packard <keithp@keithp.com>Extension specification and
implementation
Deron Johnson <deron.johnson@sun.com>
Overlay Window specification and
implementation
<pubdate>23 April 2007</pubdate> |