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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 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 XSeg-ment XSegment
       ment structures and does not perform joining at coincident endpoints.  For any given line, XDrawSeg-ments XDrawSegments
       ments 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 compo-nents: components:
       nents: foreground, background, tile, stipple, tile-stipple-x-origin, tile-stipple-y-origin, dash-off-set, dash-offset,
       set, 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 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



X Version 11                                    libX11 1.2.1                                    XDrawLine(3)