The
gdk-pixbuf
Library
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X Drawables to Pixbufs
Name
X Drawables to Pixbufs -- Getting parts of an X drawable's image data into a pixbuf.
Synopsis
#include <gdk-pixbuf/gdk-pixbuf.h>
GdkPixbuf*
gdk-pixbuf-gdk-pixbuf-xlib-from-drawables.html#GDK-PIXBUF-XLIB-GET-FROM-DRAWABLE
gdk_pixbuf_xlib_get_from_drawable
(GdkPixbuf *dest,
Drawable src,
Colormap cmap,
Visual *visual,
int src_x,
int src_y,
int dest_x,
int dest_y,
int width,
int height);
Description
The functions in this section allow you to take the image data
from an X drawable and dump it into a GdkPixbuf.  This can be
used for screenshots and other special effects.  Note that these
operations can be expensive, since the image data has to be
transferred from the X server to the client program and converted.
These functions are analogous to those for the Gdk version of
gdk-pixbuf
.
Details
gdk_pixbuf_xlib_get_from_drawable ()
GdkPixbuf*  gdk_pixbuf_xlib_get_from_drawable
(GdkPixbuf *dest,
Drawable src,
Colormap cmap,
Visual *visual,
int src_x,
int src_y,
int dest_x,
int dest_y,
int width,
int height);
Transfers image data from a Gdk drawable and converts it to an RGB(A)
representation inside a GdkPixbuf.
If the drawable
src
is a pixmap, then a suitable colormap must be specified,
since pixmaps are just blocks of pixel data without an associated colormap.
If the drawable is a window, the
cmap
argument will be ignored and the
window's own colormap will be used instead.
If the specified destination pixbuf
dest
is
NULL
, then this function will
create an RGB pixbuf with 8 bits per channel and no alpha, with the same size
specified by the
width
and
height
arguments.  In this case, the
dest_x
and
dest_y
arguments must be specified as 0, otherwise the function will return
NULL
.  If the specified destination pixbuf is not
NULL
and it contains alpha
information, then the filled pixels will be set to full opacity.
If the specified drawable is a pixmap, then the requested source rectangle
must be completely contained within the pixmap, otherwise the function will
return
NULL
.
If the specified drawable is a window, then it must be viewable, i.e. all of
its ancestors up to the root window must be mapped.  Also, the specified
source rectangle must be completely contained within the window and within
the screen.  If regions of the window are obscured by noninferior windows, the
contents of those regions are undefined.  The contents of regions obscured by
inferior windows of a different depth than that of the source window will also
be undefined.
dest
:
Destination pixbuf, or
NULL
if a new pixbuf should be created.
src
:
Source drawable.
cmap
:
A colormap if
src
is a pixmap.  If it is a window, this argument will
be ignored.
visual
:
A visual if
src
is a pixmap.  If it is a window, this argument will
be ignored.
src_x
:
Source X coordinate within drawable.
src_y
:
Source Y coordinate within drawable.
dest_x
:
Destination X coordinate in pixbuf, or 0 if
dest
is
NULL
.
dest_y
:
Destination Y coordinate in pixbuf, or 0 if
dest
is
NULL
.
width
:
Width in pixels of region to get.
height
:
Height in pixels of region to get.
Returns
:
The same pixbuf as
dest
if it was non-
NULL
, or a newly-created
pixbuf with a reference count of 1 if no destination pixbuf was specified; in
the latter case,
NULL
will be returned if not enough memory could be
allocated for the pixbuf to be created.
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Xlib Rendering
XlibRGB
