XDrawLine(3X)                                       XDrawLine(3X)



NAME
     XDrawLine,  XDrawLines,  XDrawSegments  -  draw  lines   and
     polygons and use the XSegment 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;

DESCRIPTION
     The XDrawLine function uses the components of the specified
     graphic context 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
     graphic context to draw npoints-1 lines between each pair of
     points (point[i], point[i+1]) in the array of XPoint struc-
     tures.  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 (a line width of
     0) lines intersect, the intersecting pixels are drawn multi-
     ple times.  If wide lines intersect, the intersecting pixels
     are drawn only once, as though the entire PolyLine protocol
     request were a single, filled shape.  The value of mode can
     be CoordModeOrigin or CoordModePrevious.
     CoordModeOrigin causes all coordinates to be treated as re-
     lative to the origin, and CoordModePrevious causes all coor-
     dinates after the first to be treated as relative to the
     previous point.




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XDrawLine(3X)                                       XDrawLine(3X)



     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 per-
     form 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 graphic context 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 graphic context component.

     All three functions also use these mode-dependent graphic
     context components:  foreground, background, tile, stipple,
     tile-stipple-x-origin, tile-stipple-y-origin, dash-offset,
     and dash-list.

   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.

   Arguments
     These functions accept the following arguments:

     d       Specifies the drawable.

     display Specifies the connection to the X server.

     gc      Specifies the graphic context.

     mode    Specifies the coordinate mode.  CoordModeOrigin
             treats all coordinates as related to the origin, and
             CoordModePrevious treats all coordinates after the
             first as relative to the previous point.

     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.



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XDrawLine(3X)                                       XDrawLine(3X)



     segments
             Specifies a pointer to an array of segments.

     x1, y1, x2, y2
             Specify the points used to connect the line.  Thus,
             XDrawLine draws a line connecting point x1,y1 to
             point x2,y2.

ERRORS
     BadDrawable
             A value for a Drawable argument does not name a de-
             fined window or pixel map.

     BadGC   A value for a GC argument does not name a defined
             graphic context.

     BadMatch
             An InputOnly window is used as a drawable; or, an
             argument or pair of arguments has the correct type
             and range but fails to match in some other required
             way.

     BadValue
             A numeric value falls outside the range of values
             accepted by the request.  Unless a range is speci-
             fied 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.

     XDrawLine, XDrawLines, and XDrawSegments can generate Bad-
     Drawable, BadGC, and BadMatch errors.
     XDrawLines can also generate a BadValue error.

SEE ALSO
     XCreateGC(3X), XDrawArc(3X), XDrawPoint(3X),
     XDrawRectangle(3X)

     Xlib - C Language Interface


















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