XSetLineAttributes(3X11) XLIB FUNCTIONS XSetLineAttributes(3X11)
NAME
XSetLineAttributes, XSetDashes - GC convenience routines
SYNTAX
int XSetLineAttributes(Display *display, GC gc, unsigned int
line_width, int line_style, int cap_style, int
join_style);
int XSetDashes(Display *display, GC gc, int dash_offset,
char dash_list[], int n);
ARGUMENTS
cap_style Specifies the line-style and cap-style you want to
set for the specified GC. You can pass CapNotLast,
CapButt, CapRound, or CapProjecting.
dash_list Specifies the dash-list for the dashed line-style
you want to set for the specified GC.
dash_offset
Specifies the phase of the pattern for the dashed
line-style you want to set for the specified GC.
display Specifies the connection to the X server.
gc Specifies the GC.
join_style
Specifies the line join-style you want to set for
the specified GC. You can pass JoinMiter, Join-
Round, or JoinBevel.
line_style
Specifies the line-style you want to set for the
specified GC. You can pass LineSolid, LineOnOff-
Dash, or LineDoubleDash.
line_width
Specifies the line-width you want to set for the
specified GC.
n Specifies the number of elements in dash_list.
DESCRIPTION
The XSetLineAttributes function sets the line drawing com-
ponents in the specified GC.
XSetLineAttributes can generate BadAlloc, BadGC, and Bad-
Value errors.
The XSetDashes function sets the dash-offset and dash-list
attributes for dashed line styles in the specified GC. There
XFree86 Version 4.5.0 1
XSetLineAttributes(3X11) XLIB FUNCTIONS XSetLineAttributes(3X11)
must be at least one element in the specified dash_list, or
a BadValue error results. The initial and alternating ele-
ments (second, fourth, and so on) of the dash_list are the
even dashes, and the others are the odd dashes. Each element
specifies a dash length in pixels. All of the elements must
be nonzero, or a BadValue error results. Specifying an odd-
length list is equivalent to specifying the same list con-
catenated with itself to produce an even-length list.
The dash-offset defines the phase of the pattern, specifying
how many pixels into the dash-list the pattern should actu-
ally begin in any single graphics request. Dashing is con-
tinuous through path elements combined with a join-style but
is reset to the dash-offset between each sequence of joined
lines.
The unit of measure for dashes is the same for the ordinary
coordinate system. Ideally, a dash length is measured along
the slope of the line, but implementations are only required
to match this ideal for horizontal and vertical lines. Fail-
ing the ideal semantics, it is suggested that the length be
measured along the major axis of the line. The major axis is
defined as the x axis for lines drawn at an angle of between
-45 and +45 degrees or between 135 and 225 degrees from the
x axis. For all other lines, the major axis is the y axis.
XSetDashes can generate BadAlloc, BadGC, 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.
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 gen-
erate this error.
SEE ALSO
XCreateGC(3X11), XQueryBestSize(3X11), XSetArcMode(3X11),
XSetClipOrigin(3X11), XSetFillStyle(3X11), XSetFont(3X11),
XSetState(3X11), XSetTile(3X11)
Xlib - C Language X Interface
XFree86 Version 4.5.0 2