| 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="glGetQueryObject"> |
| 5 | <refmeta> |
| 6 | <refmetainfo> |
| 7 | <copyright> |
| 8 | <year>2005</year> |
| 9 | <holder>Sams Publishing</holder> |
| 10 | </copyright> |
| 11 | </refmetainfo> |
| 12 | <refentrytitle>glGetQueryObject</refentrytitle> |
| 13 | <manvolnum>3G</manvolnum> |
| 14 | </refmeta> |
| 15 | <refnamediv> |
| 16 | <refname>glGetQueryObject</refname> |
| 17 | <refpurpose>return parameters of a query object</refpurpose> |
| 18 | </refnamediv> |
| 19 | <refsynopsisdiv><title>C Specification</title> |
| 20 | <funcsynopsis> |
| 21 | <funcprototype> |
| 22 | <funcdef>void <function>glGetQueryObjectiv</function></funcdef> |
| 23 | <paramdef>GLuint <parameter>id</parameter></paramdef> |
| 24 | <paramdef>GLenum <parameter>pname</parameter></paramdef> |
| 25 | <paramdef>GLint * <parameter>params</parameter></paramdef> |
| 26 | </funcprototype> |
| 27 | </funcsynopsis> |
| 28 | <funcsynopsis> |
| 29 | <funcprototype> |
| 30 | <funcdef>void <function>glGetQueryObjectuiv</function></funcdef> |
| 31 | <paramdef>GLuint <parameter>id</parameter></paramdef> |
| 32 | <paramdef>GLenum <parameter>pname</parameter></paramdef> |
| 33 | <paramdef>GLuint * <parameter>params</parameter></paramdef> |
| 34 | </funcprototype> |
| 35 | </funcsynopsis> |
| 36 | <funcsynopsis> |
| 37 | <funcprototype> |
| 38 | <funcdef>void <function>glGetQueryObjecti64v</function></funcdef> |
| 39 | <paramdef>GLuint <parameter>id</parameter></paramdef> |
| 40 | <paramdef>GLenum <parameter>pname</parameter></paramdef> |
| 41 | <paramdef>GLint64 * <parameter>params</parameter></paramdef> |
| 42 | </funcprototype> |
| 43 | </funcsynopsis> |
| 44 | <funcsynopsis> |
| 45 | <funcprototype> |
| 46 | <funcdef>void <function>glGetQueryObjectui64v</function></funcdef> |
| 47 | <paramdef>GLuint <parameter>id</parameter></paramdef> |
| 48 | <paramdef>GLenum <parameter>pname</parameter></paramdef> |
| 49 | <paramdef>GLuint64 * <parameter>params</parameter></paramdef> |
| 50 | </funcprototype> |
| 51 | </funcsynopsis> |
| 52 | </refsynopsisdiv> |
| 53 | <refsect1 id="parameters"><title>Parameters</title> |
| 54 | <variablelist> |
| 55 | <varlistentry> |
| 56 | <term><parameter>id</parameter></term> |
| 57 | <listitem> |
| 58 | <para> |
| 59 | Specifies the name of a query object. |
| 60 | </para> |
| 61 | </listitem> |
| 62 | </varlistentry> |
| 63 | <varlistentry> |
| 64 | <term><parameter>pname</parameter></term> |
| 65 | <listitem> |
| 66 | <para> |
| 67 | Specifies the symbolic name of a query object parameter. |
| 68 | Accepted values are <constant>GL_QUERY_RESULT</constant> or <constant>GL_QUERY_RESULT_AVAILABLE</constant>. |
| 69 | </para> |
| 70 | </listitem> |
| 71 | </varlistentry> |
| 72 | <varlistentry> |
| 73 | <term><parameter>params</parameter></term> |
| 74 | <listitem> |
| 75 | <para> |
| 76 | Returns the requested data. |
| 77 | </para> |
| 78 | </listitem> |
| 79 | </varlistentry> |
| 80 | </variablelist> |
| 81 | </refsect1> |
| 82 | <refsect1 id="description"><title>Description</title> |
| 83 | <para> |
| 84 | <function>glGetQueryObject</function> returns in <parameter>params</parameter> a selected parameter of the query object |
| 85 | specified by <parameter>id</parameter>. |
| 86 | </para> |
| 87 | <para> |
| 88 | <parameter>pname</parameter> names a specific query object parameter. <parameter>pname</parameter> can be as follows: |
| 89 | </para> |
| 90 | <variablelist> |
| 91 | <varlistentry> |
| 92 | <term><constant>GL_QUERY_RESULT</constant></term> |
| 93 | <listitem> |
| 94 | <para> |
| 95 | <parameter>params</parameter> returns the value of the query object's passed samples counter. |
| 96 | The initial value is 0. |
| 97 | </para> |
| 98 | </listitem> |
| 99 | </varlistentry> |
| 100 | <varlistentry> |
| 101 | <term><constant>GL_QUERY_RESULT_AVAILABLE</constant></term> |
| 102 | <listitem> |
| 103 | <para> |
| 104 | <parameter>params</parameter> returns whether the passed samples counter is immediately available. |
| 105 | If a delay would occur waiting for the query result, <constant>GL_FALSE</constant> is returned. |
| 106 | Otherwise, <constant>GL_TRUE</constant> is returned, which also indicates that the results of all |
| 107 | previous queries are available as well. |
| 108 | </para> |
| 109 | </listitem> |
| 110 | </varlistentry> |
| 111 | </variablelist> |
| 112 | </refsect1> |
| 113 | <refsect1 id="notes"><title>Notes</title> |
| 114 | <para> |
| 115 | If an error is generated, |
| 116 | no change is made to the contents of <parameter>params</parameter>. |
| 117 | </para> |
| 118 | <para> |
| 119 | <function>glGetQueryObject</function> implicitly flushes the GL pipeline so that any incomplete rendering |
| 120 | delimited by the occlusion query completes in finite time. |
| 121 | </para> |
| 122 | <para> |
| 123 | If multiple queries are issued using the same query object <parameter>id</parameter> before calling |
| 124 | <function>glGetQueryObject</function>, the results of the most recent query will be returned. In this case, |
| 125 | when issuing a new query, the results of the previous query are discarded. |
| 126 | </para> |
| 127 | <para> |
| 128 | <function>glGetQueryObjecti64v</function> and <function>glGetQueryObjectui64v</function> are available only |
| 129 | if the GL version is 3.3 or greater. |
| 130 | </para> |
| 131 | </refsect1> |
| 132 | <refsect1 id="errors"><title>Errors</title> |
| 133 | <para> |
| 134 | <constant>GL_INVALID_ENUM</constant> is generated if <parameter>pname</parameter> is not an accepted value. |
| 135 | </para> |
| 136 | <para> |
| 137 | <constant>GL_INVALID_OPERATION</constant> is generated if <parameter>id</parameter> is not the name of a query object. |
| 138 | </para> |
| 139 | <para> |
| 140 | <constant>GL_INVALID_OPERATION</constant> is generated if <parameter>id</parameter> is the name of a currently active |
| 141 | query object. |
| 142 | </para> |
| 143 | </refsect1> |
| 144 | <refsect1 id="seealso"><title>See Also</title> |
| 145 | <para> |
| 146 | <citerefentry><refentrytitle>glBeginQuery</refentrytitle></citerefentry>, |
| 147 | <citerefentry><refentrytitle>glEndQuery</refentrytitle></citerefentry>, |
| 148 | <citerefentry><refentrytitle>glGetQueryiv</refentrytitle></citerefentry>, |
| 149 | <citerefentry><refentrytitle>glIsQuery</refentrytitle></citerefentry>, |
| 150 | <citerefentry><refentrytitle>glQueryCounter</refentrytitle></citerefentry> |
| 151 | </para> |
| 152 | </refsect1> |
| 153 | <refsect1 id="Copyright"><title>Copyright</title> |
| 154 | <para> |
| 155 | Copyright <trademark class="copyright"></trademark> 2005 Addison-Wesley. |
| 156 | This material may be distributed subject to the terms and conditions set forth in |
| 157 | the Open Publication License, v 1.0, 8 June 1999. |
| 158 | <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>. |
| 159 | </para> |
| 160 | </refsect1> |
| 161 | </refentry> |