1GLLINEWIDTH(3G) [FIXME: manual] GLLINEWIDTH(3G)
2
6 glLineWidth - specify the width of rasterized lines
7
9 void glLineWidth(GLfloat width);
10
12 width
13 Specifies the width of rasterized lines. The initial value is 1.
14
16 glLineWidth specifies the rasterized width of both aliased and
17 antialiased lines. Using a line width other than 1 has different
18 effects, depending on whether line antialiasing is enabled. To enable
19 and disable line antialiasing, call glEnable() and
20 glDisable with argument GL_LINE_SMOOTH. Line antialiasing is initially
22 disabled.
23 If line antialiasing is disabled, the actual width is determined by
25 rounding the supplied width to the nearest integer. (If the rounding
26 results in the value 0, it is as if the line width were 1.) If Δ x >= Δ
27 y, i pixels are filled in each column that is rasterized, where i is
28 the rounded value of width. Otherwise, i pixels are filled in each row
29 that is rasterized.
30 If antialiasing is enabled, line rasterization produces a fragment for
32 each pixel square that intersects the region lying within the rectangle
33 having width equal to the current line width, length equal to the
34 actual length of the line, and centered on the mathematical line
35 segment. The coverage value for each fragment is the window coordinate
36 area of the intersection of the rectangular region with the
37 corresponding pixel square. This value is saved and used in the final
38 rasterization step.
39 Not all widths can be supported when line antialiasing is enabled. If
41 an unsupported width is requested, the nearest supported width is used.
42 Only width 1 is guaranteed to be supported; others depend on the
43 implementation. Likewise, there is a range for aliased line widths as
44 well. To query the range of supported widths and the size difference
45 between supported widths within the range, call glGet() with arguments
46 GL_ALIASED_LINE_WIDTH_RANGE, GL_SMOOTH_LINE_WIDTH_RANGE, and
47 GL_SMOOTH_LINE_WIDTH_GRANULARITY.
48
50 The line width specified by glLineWidth is always returned when
51 GL_LINE_WIDTH is queried. Clamping and rounding for aliased and
52 antialiased lines have no effect on the specified value.
53 Nonantialiased line width may be clamped to an implementation-dependent
55 maximum. Call glGet() with GL_ALIASED_LINE_WIDTH_RANGE to determine the
56 maximum width.
57 In OpenGL 1.2, the tokens GL_LINE_WIDTH_RANGE and
59 GL_LINE_WIDTH_GRANULARITY were replaced by GL_ALIASED_LINE_WIDTH_RANGE,
60 GL_SMOOTH_LINE_WIDTH_RANGE, and GL_SMOOTH_LINE_WIDTH_GRANULARITY. The
61 old names are retained for backward compatibility, but should not be
62 used in new code.
63
65 GL_INVALID_VALUE is generated if width is less than or equal to 0.
66
68 glGet() with argument GL_LINE_WIDTH
69 glGet() with argument GL_ALIASED_LINE_WIDTH_RANGE
71 glGet() with argument GL_SMOOTH_LINE_WIDTH_RANGE
73 glGet() with argument GL_SMOOTH_LINE_WIDTH_GRANULARITY
75 glIsEnabled() with argument GL_LINE_SMOOTH
77
79 ┌────────────┬───────────────────────────────────────────────────────────────────────┐
80 │ │ OpenGL Version │
81 ├────────────┼─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┤
82 │Function │ 2.0 │ 2.1 │ 3.0 │ 3.1 │ 3.2 │ 3.3 │ 4.0 │ 4.1 │ 4.2 │ 4.3 │ 4.4 │ 4.5 │
83 │/ │ │ │ │ │ │ │ │ │ │ │ │ │
84 │Feature │ │ │ │ │ │ │ │ │ │ │ │ │
85 │Name │ │ │ │ │ │ │ │ │ │ │ │ │
86 ├────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
87 │glLineWidth │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │
88 └────────────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┘
89
91 glEnable()
92
94 Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2010-2014
95 Khronos Group. This document is licensed under the SGI Free Software B
96 License. For details, see http://oss.sgi.com/projects/FreeB/.
97
99 Copyright © 1991-2006 Silicon Graphics, Inc.
100 Copyright © 2010-2014 Khronos Group
101[FIXME: source] 07/13/2018 GLLINEWIDTH(3G)