XDrawLine(3X11)             X Version 11(Release 5)             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 specified GC to draw a
      line between the specified set of points (x1, y1) and (x2, y2).  It does


10/89                                                                    Page 1

XDrawLine(3X11)             X Version 11(Release 5)             XDrawLine(3X11)


      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 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
      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
      BadDrawable
                A value for a Drawable argument does not name a defined Window
                or Pixmap.




Page 2                                                                    10/89

XDrawLine(3X11)             X Version 11(Release 5)             XDrawLine(3X11)


      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 correct 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 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)
      Xlib - C Language X Interface




































10/89                                                                    Page 3