XDrawLine(3X11) MIT X11R4 XDrawLine(3X11)
Name
XDrawLine, XDrawLines, XDrawSegments, XSegment - draw lines, polygons, and line structure
Syntax
XDrawLine(display, d, gc, x1, y1, x2, y2)
Display *display;
Drawable d;
GC gc;
int x1, y1, x2, y2;
XDrawLines(display, d, gc, points, npoints, mode)
Display *display;
Drawable d;
GC gc;
XPoint *points;
int npoints;
int mode;
XDrawSegments(display, d, gc, segments, nsegments)
Display *display;
Drawable d;
GC gc;
XSegment *segments;
int nsegments;
Arguments
d Specifies the drawable.
display Specifies the connection to the X server.
gc Specifies the GC.
mode Specifies the coordinate mode. You can pass or
npoints Specifies the number of points in the array.
nsegments Specifies the number of segments in the array.
points Specifies a pointer to an array of points.
segments Specifies a pointer to an array of segments.
x1
y1
x2
y2 Specify the points (x1, y1) and (x2, y2) to be connected.
Description
The function uses the components of the specified GC to draw a line between the specified set of points (x1, y1) and (x2, y2). It does not
perform joining at coincident endpoints. For any given line, does not draw a pixel more than once. If lines intersect, the intersecting
pixels are drawn multiple times.
The function uses the components of the specified GC to draw npoints-1 lines between each pair of points (point[i], point[i+1]) in the
array of structures. It draws the lines in the order listed in the array. The lines join correctly at all intermediate points, and if the
first and last points coincide, the first and last lines also join correctly. For any given line, does not draw a pixel more than once.
If thin (zero line-width) lines intersect, the intersecting pixels are drawn multiple times. If wide lines intersect, the intersecting
pixels are drawn only once, as though the entire protocol request were a single, filled shape. treats all coordinates as relative to the
origin, and treats all coordinates after the first as relative to the previous point.
The function draws multiple, unconnected lines. For each segment, draws a line between (x1, y1) and (x2, y2). It draws the lines in the
order listed in the array of structures and does not perform joining at coincident endpoints. For any given line, does not draw a pixel
more than once. If lines intersect, the intersecting pixels are drawn multiple times.
All three functions use these GC components: function, plane-mask, line-width, line-style, cap-style, fill-style, subwindow-mode, clip-x-
origin, clip-y-origin, and clip-mask. The function also uses the join-style GC component. All three functions also use these GC mode-
dependent components: foreground, background, tile, stipple, tile-stipple-x-origin, tile-stipple-y-origin, dash-offset, and dash-list.
and can generate and errors. can also generate a error.
Structures
The structure contains:
typedef struct {
short x1, y1, x2, y2;
} XSegment;
All x and y members are signed integers. The width and height members are 16-bit unsigned integers. You should be careful not to generate
coordinates and sizes out of the 16-bit ranges, because the protocol only has 16-bit fields for these values.
Diagnostics
A value for a Drawable argument does not name a defined Window or Pixmap.
A value for a GContext argument does not name a defined GContext.
An window is used as a Drawable.
Some argument or pair of arguments has the correct type and range but fails
to match in some other way required by the request.
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
XDrawArc(3X11), XDrawPoint(3X11), XDrawRectangle(3X11)
X Window System: The Complete Reference, Second Edition, Robert W. Scheifler and James Gettys
XDrawLine(3X11)