XDrawLine(3X11)XDrawLine(3X11)NAME
XDrawLine, XDrawLines, XDrawSegments, XSegment - draw lines, polygons,
and line structure
SYNOPSIS
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
Specifies the drawable. Specifies the connection to the X server.
Specifies the GC. Specifies the coordinate mode. You can pass Coord‐
ModeOrigin or CoordModePrevious. Specifies the number of points in the
array. Specifies the number of segments in the array. Specifies an
array of points. Specifies an array of segments. Specify the points
(x1, y1) and (x2, y2) to be connected.
DESCRIPTION
The XDrawLine 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,
XDrawLine does not draw a pixel more than once. If lines intersect, the
intersecting pixels are drawn multiple times.
The XDrawLines 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 XPoint 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, XDrawLines does not draw a pixel
more than once. If thin (zero line-width) lines intersect, the inter‐
secting pixels are drawn multiple times. If wide lines intersect, the
intersecting pixels are drawn only once, as though the entire PolyLine
protocol request were a single, filled shape. CoordModeOrigin treats
all coordinates as relative to the origin, and CoordModePrevious treats
all coordinates after the first as relative to the previous point.
The XDrawSegments function draws multiple, unconnected lines. For each
segment, XDrawSegments draws a line between (x1, y1) and (x2, y2). It
draws the lines in the order listed in the array of XSegment structures
and does not perform joining at coincident endpoints. For any given
line, XDrawSegments 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 XDrawLines 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.
XDrawLine, XDrawLines, and XDrawSegments can generate BadDrawable,
BadGC, and BadMatch errors. XDrawLines can also generate a BadValue
error.
STRUCTURES
The XSegment 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 GCon‐
text. An InputOnly 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 out‐
side the range of values accepted by the request. Unless a specific
range is specified for an argument, the full range defined by the argu‐
ment's type is accepted. Any argument defined as a set of alternatives
can generate this error.
SEE ALSOXDrawArc(3X11), XDrawPoint(3X11), XDrawRectangle(3X11)
Xlib -- C Language X Interface
XDrawLine(3X11)
