NAME
XSetClipOrigin, XSetClipMask, XSetClipRectangles - GC convenience
routines
SYNTAX
int XSetClipOrigin(Display *display, GC gc, int clip_x_origin, int
clip_y_origin);
int XSetClipMask(Display *display, GC gc, Pixmap pixmap);
int XSetClipRectangles(Display *display, GC gc, int clip_x_origin, int
clip_y_origin, XRectangle rectangles[], int n, int ordering);
ARGUMENTS
display Specifies the connection to the X server.
clip_x_origin
clip_y_origin
Specify the x and y coordinates of the clip-mask origin.
gc Specifies the GC.
n Specifies the number of rectangles.
ordering Specifies the ordering relations on the rectangles. You can
pass Unsorted, YSorted, YXSorted, or YXBanded.
pixmap Specifies the pixmap or None.
rectangles
Specifies an array of rectangles that define the clip-mask.
DESCRIPTION
The XSetClipOrigin function sets the clip origin in the specified GC.
The clip-mask origin is interpreted relative to the origin of whatever
destination drawable is specified in the graphics request.
XSetClipOrigin can generate BadAlloc and BadGC errors.
The XSetClipMask function sets the clip-mask in the specified GC to the
specified pixmap. If the clip-mask is set to None, the pixels are are
always drawn (regardless of the clip-origin).
XSetClipMask can generate BadAlloc, BadGC, BadMatch, and BadValue
errors.
The XSetClipRectangles function changes the clip-mask in the specified
GC to the specified list of rectangles and sets the clip origin. The
output is clipped to remain contained within the rectangles. The clip-
origin is interpreted relative to the origin of whatever destination
drawable is specified in a graphics request. The rectangle coordinates
are interpreted relative to the clip-origin. The rectangles should be
nonintersecting, or the graphics results will be undefined. Note that
the list of rectangles can be empty, which effectively disables output.
This is the opposite of passing None as the clip-mask in XCreateGC,
XChangeGC, and XSetClipMask.
If known by the client, ordering relations on the rectangles can be
specified with the ordering argument. This may provide faster
operation by the server. If an incorrect ordering is specified, the X
server may generate a BadMatch error, but it is not required to do so.
If no error is generated, the graphics results are undefined. Unsorted
means the rectangles are in arbitrary order. YSorted means that the
rectangles are nondecreasing in their Y origin. YXSorted additionally
constrains YSorted order in that all rectangles with an equal Y origin
are nondecreasing in their X origin. YXBanded additionally constrains
YXSorted by requiring that, for every possible Y scanline, all
rectangles that include that scanline have an identical Y origins and Y
extents.
XSetClipRectangles can generate BadAlloc, BadGC, BadMatch, and BadValue
errors.
DIAGNOSTICS
BadAlloc The server failed to allocate the requested resource or
server memory.
BadGC A value for a GContext argument does not name a defined
GContext.
BadMatch Some argument or pair of arguments has the correct type and
range but fails to match in some other way required by the
request.
BadValue Some numeric value falls outside the range of values accepted
by the request. Unless a specific range is specified for an
argument, the full range defined by the argument’s type is
accepted. Any argument defined as a set of alternatives can
generate this error.
SEE ALSO
XCreateGC(3), XDrawRectangle(3), XQueryBestSize(3), XSetArcMode(3),
XSetFillStyle(3), XSetFont(3), XSetLineAttributes(3), XSetState(3),
XSetTile(3)
Xlib - C Language X Interface