Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
XDrawLine(3)			 XLIB FUNCTIONS 		    XDrawLine(3)

NAME
     XDrawLine,  XDrawLines, XDrawSegments, XSegment - draw lines, polygons, and
     line structure

SYNTAX
     int XDrawLine(Display *display, Drawable d, GC gc, int x1, int y1, int  x2,
	    int y2);

     int  XDrawLines(Display  *display,  Drawable  d, GC gc, XPoint *points, int
	    npoints, int mode);

     int XDrawSegments(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
     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  cor-
     rectly.   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  coordi-
     nates  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 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 argu-
	       ment, 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(3), XDrawPoint(3), XDrawRectangle(3)
     Xlib - C Language X Interface

X Version 11			  libX11 1.8.13 		    XDrawLine(3)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=XDrawLines&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>

home | help