1XDrawLine(3) XLIB FUNCTIONS XDrawLine(3)
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6 XDrawLine, XDrawLines, XDrawSegments, XSegment - draw lines, polygons,
7 and line structure
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10 int XDrawLine(Display *display, Drawable d, GC gc, int x1, int y1, int
11 x2, int y2);
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13 int XDrawLines(Display *display, Drawable d, GC gc, XPoint *points, int
14 npoints, int mode);
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16 int XDrawSegments(Display *display, Drawable d, GC gc, XSegment *seg‐
17 ments, int nsegments);
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20 d Specifies the drawable.
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22 display Specifies the connection to the X server.
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24 gc Specifies the GC.
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26 mode Specifies the coordinate mode. You can pass CoordModeOrigin
27 or CoordModePrevious.
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29 npoints Specifies the number of points in the array.
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31 nsegments Specifies the number of segments in the array.
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33 points Specifies an array of points.
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35 segments Specifies an array of segments.
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37 x1
38 y1
39 x2
40 y2 Specify the points (x1, y1) and (x2, y2) to be connected.
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43 The XDrawLine function uses the components of the specified GC to draw
44 a line between the specified set of points (x1, y1) and (x2, y2). It
45 does not perform joining at coincident endpoints. For any given line,
46 XDrawLine does not draw a pixel more than once. If lines intersect,
47 the intersecting pixels are drawn multiple times.
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49 The XDrawLines function uses the components of the specified GC to draw
50 npoints-1 lines between each pair of points (point[i], point[i+1]) in
51 the array of XPoint structures. It draws the lines in the order listed
52 in the array. The lines join correctly at all intermediate points, and
53 if the first and last points coincide, the first and last lines also
54 join correctly. For any given line, XDrawLines does not draw a pixel
55 more than once. If thin (zero line-width) lines intersect, the inter‐
56 secting pixels are drawn multiple times. If wide lines intersect, the
57 intersecting pixels are drawn only once, as though the entire PolyLine
58 protocol request were a single, filled shape. CoordModeOrigin treats
59 all coordinates as relative to the origin, and CoordModePrevious treats
60 all coordinates after the first as relative to the previous point.
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62 The XDrawSegments function draws multiple, unconnected lines. For each
63 segment, XDrawSegments draws a line between (x1, y1) and (x2, y2). It
64 draws the lines in the order listed in the array of XSegment structures
65 and does not perform joining at coincident endpoints. For any given
66 line, XDrawSegments does not draw a pixel more than once. If lines
67 intersect, the intersecting pixels are drawn multiple times.
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69 All three functions use these GC components: function, plane-mask,
70 line-width, line-style, cap-style, fill-style, subwindow-mode, clip-x-
71 origin, clip-y-origin, and clip-mask. The XDrawLines function also
72 uses the join-style GC component. All three functions also use these
73 GC mode-dependent components: foreground, background, tile, stipple,
74 tile-stipple-x-origin, tile-stipple-y-origin, dash-offset, and dash-
75 list.
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77 XDrawLine, XDrawLines, and XDrawSegments can generate BadDrawable,
78 BadGC, and BadMatch errors. XDrawLines can also generate a BadValue
79 error.
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82 The XSegment structure contains:
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84 typedef struct {
85 short x1, y1, x2, y2;
86 } XSegment;
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88 All x and y members are signed integers. The width and height members
89 are 16-bit unsigned integers. You should be careful not to generate
90 coordinates and sizes out of the 16-bit ranges, because the protocol
91 only has 16-bit fields for these values.
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94 BadDrawable
95 A value for a Drawable argument does not name a defined Win‐
96 dow or Pixmap.
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98 BadGC A value for a GContext argument does not name a defined GCon‐
99 text.
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101 BadMatch An InputOnly window is used as a Drawable.
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103 BadMatch Some argument or pair of arguments has the correct type and
104 range but fails to match in some other way required by the
105 request.
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107 BadValue Some numeric value falls outside the range of values accepted
108 by the request. Unless a specific range is specified for an
109 argument, the full range defined by the argument's type is
110 accepted. Any argument defined as a set of alternatives can
111 generate this error.
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114 XDrawArc(3), XDrawPoint(3), XDrawRectangle(3)
115 Xlib - C Language X Interface
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119X Version 11 libX11 1.3.4 XDrawLine(3)