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<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.1 plus MathML 2.0//EN" "http://www.w3.org/TR/MathML2/dtd/xhtml-math11-f.dtd">
<html
xmlns="http://www.w3.org/1999/xhtml"
xmlns:mml="http://www.w3.org/1998/Math/MathML"
><head><title>glLineWidth</title><link rel="stylesheet" href="style.css" type="text/css"/><meta name="generator" content="DocBook XSL Stylesheets V1.59.1"/><link rel="home" href="index.xml" title="PyOpenGL 2.0.1.07 Man Pages"/><link rel="up" href="reference-GL.xml" title="GL"/><link rel="previous" href="glLineStipple.3G.xml" title="glLineStipple"/><link rel="next" href="glListBase.3G.xml" title="glListBase"/></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">glLineWidth</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="glLineStipple.3G.xml">Prev</a></td><th width="60%" align="center">GL</th><td width="20%" align="right"><a accesskey="n" href="glListBase.3G.xml">Next</a></td></tr></table><hr/></div><div class="refentry" lang="en"><a name="glLineWidth.3G"/><div class="titlepage"/><div class="refnamediv"><a name="glLineWidth.3G-name"/><h2>Name</h2><p>glLineWidth — specify the width of rasterized lines</p></div><div class="refsynopsisdiv"><a name="glLineWidth.3G-c_spec"/><h2>C Specification</h2><table class="funcprototype" border="0" cellpadding="0" cellspacing="0"><tr><td valign="top"><code>void<tt>glLineWidth</tt></code></td><td valign="top"><code>(</code></td><td valign="top"><code>GLfloat<i><tt>width</tt></i>);</code></td></tr></table></div><div class="refsynopsisdiv"><a name="glLineWidth.3G-python_spec"/><h2>Python Specification</h2><table class="funcprototype" border="0" cellpadding="0" cellspacing="0"><tr><td valign="top"><code><tt>glLineWidth</tt></code></td><td valign="top"><code>(</code></td><td valign="top"><code><i><tt>width</tt></i>) →<tt>None</tt></code></td></tr></table></div><div class="refsect1" lang="en"><a name="glLineWidth.3G-parameters"/><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><i><tt>width</tt></i></span></dt><dd>
Specifies the width of rasterized lines. The initial value is 1.
</dd></dl></div></div><div class="refsect1" lang="en"><a name="glLineWidth.3G-description"/><h2>Description</h2><p>
<tt>glLineWidth</tt> specifies the rasterized width of both aliased and antialiased lines. Using a line
width other than 1 has different effects, depending on whether line antialiasing is enabled. To enable and disable line
antialiasing, call <a href="glEnable.3G.xml"><tt>glEnable</tt></a> and <a href="glEnable.3G.xml"><tt>glDisable</tt></a> with argument <tt>GL_LINE_SMOOTH</tt>. Line antialiasing is
initially disabled.
</p><p>
If line antialiasing is disabled, the actual width is determined by rounding the supplied width to the nearest integer.
(If the rounding results in the value 0, it is as if the line width were 1.) If <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<mml:mrow>
<mml:mo>|</mml:mo>
<mml:mi>Δ</mml:mi>
<mml:mi>x</mml:mi>
<mml:mo>|</mml:mo>
<mml:mo>≥</mml:mo>
<mml:mo>|</mml:mo>
<mml:mi>Δ</mml:mi>
<mml:mi>y</mml:mi>
<mml:mo>|</mml:mo>
</mml:mrow>
</mml:math>, <i><tt>i</tt></i> pixels are filled in each column that is rasterized, where
<i><tt>i</tt></i> is the rounded value of <i><tt>width</tt></i>. Otherwise, <i><tt>i</tt></i>
pixels are filled in each row that is rasterized.
</p><p>
If antialiasing is enabled, line rasterization produces a fragment for each pixel square that intersects the region
lying within the rectangle having width equal to the current line width, length equal to the actual length of the line,
and centered on the mathematical line segment. The coverage value for each fragment is the window coordinate area of
the intersection of the rectangular region with the corresponding pixel square. This value is saved and used in the
final rasterization step.
</p><p>
Not all widths can be supported when line antialiasing is enabled. If an unsupported width is requested, the nearest
supported width is used. Only width 1 is guaranteed to be supported; others depend on the implementation. Likewise,
there is a range for aliased line widths as well. To query the range of supported widths and the size difference
between supported widths within the range, call <tt>glGet</tt> with arguments
<tt>GL_ALIASED_LINE_WIDTH_RANGE</tt>, <tt>GL_SMOOTH_LINE_WIDTH_RANGE</tt>,
<tt>GL_SMOOTH_LINE_WIDTH_GRANULARITY</tt>.
</p></div><div class="refsect1" lang="en"><a name="glLineWidth.3G-notes"/><h2>Notes</h2><p>
The line width specified by <tt>glLineWidth</tt> is always returned when <tt>GL_LINE_WIDTH</tt>
is queried. Clamping and rounding for aliased and antialiased lines have no effect on the specified value.
</p><p>
Nonantialiased line width may be clamped to an implementation-dependent maximum. Call <tt>glGet</tt> with <tt>GL_ALIASED_LINE_WIDTH_RANGE</tt> to determine the maximum
width.
</p></div><div class="refsect1" lang="en"><a name="glLineWidth.3G-errors"/><h2>Errors</h2><p>
<tt>GL_INVALID_VALUE</tt> is generated if <i><tt>width</tt></i> is less than or equal to 0.
</p><p>
<tt>GL_INVALID_OPERATION</tt> is generated if <tt>glLineWidth</tt> is executed between the
execution of <a href="glBegin.3G.xml"><tt>glBegin</tt></a> and the corresponding execution of <a href="glBegin.3G.xml"><tt>glEnd</tt></a>.
</p></div><div class="refsect1" lang="en"><a name="glLineWidth.3G-associated_gets"/><h2>Associated Gets</h2><p>
<tt>glGet</tt> with argument <tt>GL_LINE_WIDTH</tt>
</p><p>
<tt>glGet</tt> with argument <tt>GL_ALIASED_LINE_WIDTH_RANGE</tt>
</p><p>
<tt>glGet</tt> with argument <tt>GL_SMOOTH_LINE_WIDTH_RANGE</tt>
</p><p>
<tt>glGet</tt> with argument <tt>GL_SMOOTH_LINE_WIDTH_GRANULARITY</tt>
</p><p>
<a href="glIsEnabled.3G.xml"><tt>glIsEnabled</tt></a> with argument <tt>GL_LINE_SMOOTH</tt>
</p></div><div class="refsect1" lang="en"><a name="glLineWidth.3G-see_also"/><h2>See Also</h2><p>
<span class="simplelist"><a href="glEnable.3G.xml">glEnable</a></span>
</p></div></div><div class="navfooter"><hr/><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="glLineStipple.3G.xml">Prev</a></td><td width="20%" align="center"><a accesskey="u" href="reference-GL.xml">Up</a></td><td width="40%" align="right"><a accesskey="n" href="glListBase.3G.xml">Next</a></td></tr><tr><td width="40%" align="left" valign="top">glLineStipple</td><td width="20%" align="center"><a accesskey="h" href="index.xml">Home</a></td><td width="40%" align="right" valign="top">glListBase</td></tr></table></div></body></html>
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