1 <?xml version=
"1.0" encoding=
"UTF-8"?>
2 <!DOCTYPE book PUBLIC
"-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
3 "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
4 <refentry id=
"glGetMultisample">
9 <holder>Khronos Group
</holder>
12 <refentrytitle>glGetMultisamplefv
</refentrytitle>
13 <manvolnum>3G
</manvolnum>
16 <refname>glGetMultisamplefv
</refname>
17 <refpurpose>retrieve the location of a sample
</refpurpose>
19 <refsynopsisdiv><title>C Specification
</title>
22 <funcdef>void
<function>glGetMultisamplefv
</function></funcdef>
23 <paramdef>GLenum
<parameter>pname
</parameter></paramdef>
24 <paramdef>GLuint
<parameter>index
</parameter></paramdef>
25 <paramdef>GLfloat *
<parameter>val
</parameter></paramdef>
29 <!-- eqn: ignoring delim $$ -->
30 <refsect1 id=
"parameters"><title>Parameters
</title>
33 <term><parameter>pname
</parameter></term>
36 Specifies the sample parameter name.
<parameter>pname
</parameter> must be
<constant>GL_SAMPLE_POSITION
</constant>.
41 <term><parameter>index
</parameter></term>
44 Specifies the index of the sample whose position to query.
49 <term><parameter>val
</parameter></term>
52 Specifies the address of an array to receive the position of the sample.
58 <refsect1 id=
"description"><title>Description
</title>
60 <function>glGetMultisamplefv
</function> queries the location of a given sample.
<parameter>pname
</parameter>
61 specifies the sample parameter to retrieve and must be
<constant>GL_SAMPLE_POSITION
</constant>.
<parameter>index
</parameter>
62 corresponds to the sample for which the location should be returned. The sample location is returned as two floating-point
63 values in
<parameter>val[
0]
</parameter> and
<parameter>val[
1]
</parameter>, each between
0 and
1, corresponding to the
<parameter>x
</parameter>
64 and
<parameter>y
</parameter> locations respectively in the GL pixel space of that sample. (
0.5,
0.5) this corresponds to the
65 pixel center.
<parameter>index
</parameter> must be between zero and the value of
<constant>GL_SAMPLES
</constant> -
1.
68 If the multisample mode does not have fixed sample locations, the returned values may only reflect the locations of samples
72 <refsect1 id=
"errors"><title>Errors
</title>
74 <constant>GL_INVALID_ENUM
</constant> is generated if
<parameter>pname
</parameter> is not one
<constant>GL_SAMPLE_POSITION
</constant>.
77 <constant>GL_INVALID_VALUE
</constant> is generated if
<parameter>index
</parameter> is greater than or equal to the value of
78 <constant>GL_SAMPLES
</constant>.
81 <refsect1 id=
"seealso"><title>See Also
</title>
83 <citerefentry><refentrytitle>glGenFramebuffers
</refentrytitle></citerefentry>,
84 <citerefentry><refentrytitle>glBindFramebuffer
</refentrytitle></citerefentry>
87 <refsect1 id=
"Copyright"><title>Copyright
</title>
89 Copyright
<trademark class=
"copyright"></trademark> 2010 Khronos Group.
90 This material may be distributed subject to the terms and conditions set forth in
91 the Open Publication License, v
1.0,
8 June
1999.
92 <ulink url=
"http://opencontent.org/openpub/">http://opencontent.org/openpub/
</ulink>.