XDrawLines()XDrawLines()NameXDrawLines – draw multiple connected lines.
Synopsis
XDrawLines(display, drawable, gc, points, npoints, mode)
Display *display;
Drawable drawable;
GC gc;
XPoint *points;
int npoints;
int mode;
Arguments
display Specifies a connection to an X server; returned from
XOpenDisplay().
drawable Specifies the drawable.
gc Specifies the graphics context.
points Specifies a pointer to an array of points.
npoints Specifies the number of points in the array.
mode Specifies the coordinate mode. Pass either CoordModeOrigin
or CoordModePrevious.
DescriptionXDrawLines() draws a series of lines joined end-to-end.
It draws lines connecting each point in the list (points array) to the
next point in the list. The lines are drawn in the order listed in the
points array. For any given line, no pixel is drawn more than once.
If thin (zero line width) lines intersect, pixels will be drawn multi‐
ple times. If the first and last points coincide, the first and last
lines will join correctly. If wide lines intersect, the intersecting
pixels are drawn only once, as though the entire multiline request were
a single filled shape.
There is a limit to the number of lines that can be drawn in a single
call, which varies according to the server. To determine how many
lines you can draw in a single call, find out your server's maximum
request size using XMaxRequestSize(). Subtract three and divide by
two, and this is the maximum number of lines you can draw in a single
XDrawLines() call.
The mode argument may have two values:
· CoordModeOrigin indicates that all points are relative to the draw‐
able's origin.
· CoordModePrevious indicates that all points after the first are rel‐
ative to the previous point. (The first point is always relative to
the drawable's origin.)
XDrawLines() uses the following components of the specified graphics
context to draw multiple connected lines in the specified drawable:
function, plane_mask, line_width, line_style, cap_style, join_style,
fill_style, subwindow_mode, clip_x_origin, clip_y_ origin, and
clip_mask. This function also uses these graphics context mode-depen‐
dent components: foreground, background, tile, stipple, ts_x_origin,
ts_y_origin, dash_offset, and dashes.
For more information, see Volume One, Chapter 6, Drawing Graphics and
Text, and Chapter 5, The Graphics Context.
Structures
typedef struct {
short x, y;
} XPoint;
Errors
BadDrawable
Specified drawable is invalid.
BadGC Specified GC is invalid, or does not match the depth of draw‐
able.
BadMatch Specified drawable is an InputOnly window.
BadValue Invalid coordinate_mode.
See AlsoXClearArea(), XClearWindow(), XCopyArea(), XCopyPlane(), XDraw,
XDrawArc(), XDrawArcs(), XDrawFilled(), XDrawLine(), XDrawPoint(),
XDrawPoints(), XDrawRectangle(), XDrawRectangles(), XDrawSegments(),
XFillArc(), XFillArcs(), XFillPolygon(), XFillRectangle(), XFillRectan‐
gles().
Xlib - Drawing Primitives XDrawLines()
