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
                 CoordModeOrigin or CoordModePrevious.

       npoints   Specifies the number of points in the array.

       nsegments Specifies the number of segments in the array.

       points    Specifies an array of points.

       segments  Specifies an array of segments.

       x1
       y1
       x2
       y2        Specify the points (x1, y1) and (x2, y2) to be
                 connected.

DESCRIPTION
       The XDrawLine function uses the components of the speci-
       fied 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 speci-
       fied 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 intersecting
       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 coordi-
       nates 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, stip-
       ple, 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
       BadDrawable
                 A value for a Drawable argument does not name a
                 defined Window or Pixmap.

       BadGC     A value for a GContext argument does not name a
                 defined GContext.

       BadMatch  An InputOnly window is used as a Drawable.

       BadMatch  Some argument or pair of arguments has the cor-
                 rect type and range but fails to match in some
                 other way required by the request.

       BadValue  Some numeric value falls outside the range of
                 values accepted by the request.  Unless a spe-
                 cific 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) 
       Xlib - C Language X Interface