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4 Reference Pages
</title><meta name=
"generator" content=
"DocBook XSL Stylesheets V1.69.1" /></head><body><div class=
"refentry" lang=
"en" xml:
lang=
"en"><a id=
"glPatchParameter"></a><div class=
"titlepage"></div><div class=
"refnamediv"><h2>Name
</h2><p>glPatchParameter — specifies the parameters for patch primitives
</p></div><div class=
"refsynopsisdiv"><h2>C Specification
</h2><div class=
"funcsynopsis"><table border=
"0" summary=
"Function synopsis" cellspacing=
"0" cellpadding=
"0"><tr><td><code class=
"funcdef">void
<b class=
"fsfunc">glPatchParameteri
</b>(
</code></td><td>GLenum
</td><td><var class=
"pdparam">pname
</var>,
</td></tr><tr><td> </td><td>GLint
</td><td><var class=
"pdparam">value
</var><code>)
</code>;
</td></tr></table></div><div class=
"funcsynopsis"><table border=
"0" summary=
"Function synopsis" cellspacing=
"0" cellpadding=
"0"><tr><td><code class=
"funcdef">void
<b class=
"fsfunc">glPatchParameterfv
</b>(
</code></td><td>GLenum
</td><td><var class=
"pdparam">pname
</var>,
</td></tr><tr><td> </td><td>const GLfloat *
</td><td><var class=
"pdparam">values
</var><code>)
</code>;
</td></tr></table></div></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"parameters"></a><h2>Parameters
</h2><div class=
"variablelist"><dl><dt><span class=
"term"><em class=
"parameter"><code>pname
</code></em></span></dt><dd><p>
5 Specifies the name of the parameter to set. The symbolc constants
<code class=
"constant">GL_PATCH_VERTICES
</code>,
6 <code class=
"constant">GL_PATCH_DEFAULT_OUTER_LEVEL
</code>, and
<code class=
"constant">GL_PATCH_DEFAULT_INNER_LEVEL
</code> are accepted.
7 </p></dd><dt><span class=
"term"><em class=
"parameter"><code>value
</code></em></span></dt><dd><p>
8 Specifies the new value for the parameter given by
<em class=
"parameter"><code>pname
</code></em>.
9 </p></dd><dt><span class=
"term"><em class=
"parameter"><code>values
</code></em></span></dt><dd><p>
10 Specifies the address of an array containing the new values for the parameter given by
<em class=
"parameter"><code>pname
</code></em>.
11 </p></dd></dl></div></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"description"></a><h2>Description
</h2><p>
12 <code class=
"function">glPatchParameter
</code> specifies the parameters that will be used for patch primitives.
<em class=
"parameter"><code>pname
</code></em>
13 specifies the parameter to modify and must be either
<code class=
"constant">GL_PATCH_VERTICES
</code>,
<code class=
"constant">GL_PATCH_DEFAULT_OUTER_LEVEL
</code>
14 or
<code class=
"constant">GL_PATCH_DEFAULT_INNER_LEVEL
</code>. For
<code class=
"function">glPatchParameteri
</code>,
<em class=
"parameter"><code>value
</code></em> specifies
15 the new value for the parameter specified by
<em class=
"parameter"><code>pname
</code></em>. For
<code class=
"function">glPatchParameterfv
</code>,
<em class=
"parameter"><code>values
</code></em>
16 specifies the address of an array containing the new values for the parameter specified by
<em class=
"parameter"><code>pname
</code></em>.
18 When
<em class=
"parameter"><code>pname
</code></em> is
<code class=
"constant">GL_PATCH_VERTICES
</code>,
<em class=
"parameter"><code>value
</code></em> specifies the number
19 of vertices that will be used to make up a single patch primitive. Patch primitives are consumed by the tessellation control
20 shader (if present) and subsequently used for tessellation. When primitives are specified using
21 <a href=
"glDrawArrays.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glDrawArrays
</span></span></a> or a similar function, each patch will be made
22 from
<em class=
"parameter"><code>parameter
</code></em> control points, each represented by a vertex taken from the enabeld vertex arrays.
23 <em class=
"parameter"><code>parameter
</code></em> must be greater than zero, and less than or equal to the value of
<code class=
"constant">GL_MAX_PATCH_VERTICES
</code>.
25 When
<em class=
"parameter"><code>pname
</code></em> is
<code class=
"constant">GL_PATCH_DEFAULT_OUTER_LEVEL
</code> or
<code class=
"constant">GL_PATCH_DEFAULT_INNER_LEVEL
</code>,
26 <em class=
"parameter"><code>values
</code></em> contains the address of an array contiaining the default outer or inner tessellation levels, respectively,
27 to be used when no tessellation control shader is present.
28 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"errors"></a><h2>Errors
</h2><p>
29 <code class=
"constant">GL_INVALID_ENUM
</code> is generated if
<em class=
"parameter"><code>pname
</code></em> is not an accepted value.
31 <code class=
"constant">GL_INVALID_VALUE
</code> is generated if
<em class=
"parameter"><code>pname
</code></em> is
<code class=
"constant">GL_PATCH_VERTICES
</code>
32 and
<em class=
"parameter"><code>value
</code></em> is less than or equal to zero, or greater than the value of
<code class=
"constant">GL_MAX_PATCH_VERTICES
</code>.
33 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"seealso"></a><h2>See Also
</h2><p>
34 <a href=
"glDrawArrays.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glDrawArrays
</span></span></a>,
35 <a href=
"glDrawArraysInstanced.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glDrawArraysInstanced
</span></span></a>,
36 <a href=
"glDrawElements.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glDrawElements
</span></span></a>,
37 <a href=
"glDrawRangeElements.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glDrawRangeElements
</span></span></a>,
38 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"Copyright"></a><h2>Copyright
</h2><p>
39 Copyright
<span class=
"trademark"></span>©
2010 Khronos Group.
40 This material may be distributed subject to the terms and conditions set forth in
41 the Open Publication License, v
1.0,
8 June
1999.
42 <a href=
"http://opencontent.org/openpub/" target=
"_top">http://opencontent.org/openpub/
</a>.
43 </p></div></div></body></html>