XSetLineAttributes, XSetDashes - GC convenience routines
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);
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.
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.
Specifies the line join-style you want to set for the
specified GC. You can pass JoinMiter, JoinRound, or
Specifies the line-style you want to set for the specified
GC. You can pass LineSolid, LineOnOffDash, or
Specifies the line-width you want to set for the specified
n Specifies the number of elements in dash_list.
The XSetLineAttributes function sets the line drawing components in the
XSetLineAttributes can generate BadAlloc, BadGC, and BadValue errors.
The XSetDashes function sets the dash-offset and dash-list attributes
for dashed line styles in the specified GC. There must be at least one
element in the specified dash_list, or a BadValue error results. The
initial and alternating elements (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 concatenated 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 actually begin in any
single graphics request. Dashing is continuous 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. Failing 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.
BadAlloc The server failed to allocate the requested resource or
BadGC A value for a GContext argument does not name a defined
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.
XCreateGC(3), XQueryBestSize(3), XSetArcMode(3), XSetClipOrigin(3),
XSetFillStyle(3), XSetFont(3), XSetState(3), XSetTile(3)
Xlib - C Language X Interface