hpux man page for xdraw

XDraw() 																   XDraw()

Name
  XDraw - draw a polyline or curve between vertex list (from X10).

Synopsis
  Status XDraw(display, drawable, gc, vlist, vcount)
	Display *display;
	Drawable drawable;
	GC gc;
	Vertex *vlist;
	int vcount;

Arguments
  display   Specifies a connection to an X server; returned from XOpenDisplay().

  drawable  Specifies the drawable.

  gc	    Specifies the graphics context.

  vlist     Specifies a pointer to the list of vertices that indicates what to draw.

  vcount    Specifies how many vertices are in vlist.

Returns
  Zero on failure, non-zero on success.

Description
  This	function  is provided for compatibility with X Version 10.  To use it you must include the file <X11/X10.h> and link with the library
  -loldX.  Its performance is likely to be low.

  XDraw draws an arbitrary polygon or curve.  The figure drawn is defined by the specified list of vertices (vlist).   The  points  are  con-
  nected by lines as specified in the flags member of each of the Vertex structures.

  The Vertex structure contains an x,y coordinate and a bitmask called flags that specifies the drawing parameters.

  The  x  and y elements of Vertex are the coordinates of the vertex that are relative to either the previous vertex (if VertexRelative is 1)
  or the upper-left inside corner of the drawable (if VertexRelative is 0).  If VertexRelative is 0 the coordinates are said to be  absolute.
  The first vertex must be an absolute vertex.

  If  the  VertexDontDraw  bit is 1, no line or curve is drawn from the previous vertex to this one.  This is analogous to picking up the pen
  and moving to another place before drawing another line.

  If the VertexCurved bit is 1, a spline algorithm is used to draw a smooth curve from the previous vertex, through this  one,	to  the  next
  vertex.   Otherwise, a straight line is drawn from the previous vertex to this one.  It makes sense to set VertexCurved to 1 only if a pre-
  vious and next vertex are both defined (either explicitly in the array, or through the definition of a closed curve - see below).

  It is permissible for VertexDontDraw bits and VertexCurved bits to both be 1.  This is useful if you want to define the previous point  for
  the smooth curve, but you do not want an actual curve drawing to start until this point.

  If  VertexStartClosed  bit is 1, then this point marks the beginning of a closed curve.  This vertex must be followed later in the array by
  another vertex whose absolute coordinates are identical and which has VertexEndClosed bit of 1.  The points in between form a cycle for the
  purpose of determining predecessor and successor vertices for the spline algorithm.

  XDraw achieves the effects of the X10 XDraw, XDrawDashed, and XDrawPatterned functions.

  XDraw uses the following graphics context components: function, plane_mask, line_width, line_style, cap_style, join_style, fill_style, sub-
  window_ mode, clip_x_origin, clip_y_origin, and clip_mask.  This function also uses these graphics context mode-dependent components: fore-
  ground, background, tile, stipple, ts_x_origin, ts_y_origin, dash_offset, and dashes.

  A Status of zero is returned on failure, and non-zero on success.

  For more information, see Volume One, Appendix B, X10 Compatibility.

Structures
     typedef struct _Vertex {
	 short x,y;
	 unsigned short flags;
     } Vertex;

     /* defined constants for use as flags */

     #define VertexRelative	   0x0001     /* else absolute */
     #define VertexDontDraw	   0x0002     /* else draw */
     #define VertexCurved	   0x0004     /* else straight */
     #define VertexStartClosed	   0x0008     /* else not */
     #define VertexEndClosed	   0x0010     /* else not */

See Also
  XClearArea(),  XClearWindow(),  XCopyArea(), XCopyPlane(), XDrawArc(), XDrawArcs(), XDrawFilled(), XDrawLine(), XDrawLines(), XDrawPoint(),
  XDrawPoints(), XDrawRectangle(), XDrawRectangles(), XDrawSegments(), XFillArc(), XFillArcs(), XFillPolygon(), XFillRectangle(),  XFillRect-
  angles().

Xlib - Drawing Primitives														   XDraw()