upstream-man-pages/man4/glGetFramebufferParameter.xml

   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="glGetFramebufferParameter">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2012</year>
   9                 <holder>Khronos Group</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glGetFramebufferParameter</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glGetFramebufferParameter</refname>
  17         <refpurpose>retrieve a named parameter from a framebuffer</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glGetFramebufferParameteriv</function></funcdef>
  23                 <paramdef>GLenum <parameter>target</parameter></paramdef>
  24                 <paramdef>GLenum <parameter>pname</parameter></paramdef>
  25                 <paramdef>GLint * <parameter>params</parameter></paramdef>
  26             </funcprototype>
  27         </funcsynopsis>
  28     </refsynopsisdiv>
  29     <refsect1 id="parameters"><title>Parameters</title>
  30         <variablelist>
  31         <varlistentry>
  32             <term><parameter>target</parameter></term>
  33             <listitem>
  34                 <para>
  35                     The target of the operation, which must be <constant>GL_READ_FRAMEBUFFER</constant>,
  36                     <constant>GL_DRAW_FRAMEBUFFER</constant> or <constant>GL_FRAMEBUFFER</constant>.
  37                 </para>
  38             </listitem>
  39         </varlistentry>
  40         <varlistentry>
  41             <term><parameter>pname</parameter></term>
  42             <listitem>
  43                 <para>
  44                     A token indicating the parameter to be retrieved.
  45                 </para>
  46             </listitem>
  47         </varlistentry>
  48         <varlistentry>
  49             <term><parameter>params</parameter></term>
  50             <listitem>
  51                 <para>
  52                     The address of a variable to receive the value of the parameter named <parameter>pname</parameter>.
  53                 </para>
  54             </listitem>
  55         </varlistentry>
  56         </variablelist>
  57     </refsect1>
  58     <refsect1 id="description"><title>Description</title>
  59         <para>
  60             <function>glGetFramebufferParameter</function> retrieves the current value of the parameter
  61             named <parameter>pname</parameter> from the framebuffer bound to <parameter>target</parameter>.
  62             <parameter>target</parameter> must be <constant>GL_READ_FRAMEBFUFFER</constant>,
  63             <constant>GL_DRAW_FRAMEBUFFER</constant> or <constant>GL_FRAMEBUFFER</constant>. The
  64             token <constant>GL_FRAMEBUFFER</constant> is treated as <constant>GL_DRAW_FRAMEBUFFER</constant>.
  65             A non-default framebuffer must be bound to <parameter>target</parameter>.
  66         </para>
  67         <para>
  68             <parameter>pname</parameter> specifies the parameter to be retrieved. The values retrieved from
  69             the framebuffer are written into the variable whose address is given by <parameter>params</parameter>.
  70             The following symbols are accepted in <parameter>pname</parameter>:
  71         </para>
  72         <variablelist>
  73             <varlistentry>
  74                 <term><constant>GL_FRAMEBUFFER_DEFAULT_WIDTH</constant></term>
  75                 <listitem>
  76                     <para>
  77                         The value of <constant>GL_FRAMEBUFFER_DEFAULT_WIDTH</constant> for the framebuffer is written to the
  78                         single integer variable whose address is given by <parameter>params</parameter>.
  79                     </para>
  80                 </listitem>
  81             </varlistentry>
  82             <varlistentry>
  83                 <term><constant>GL_FRAMEBUFFER_DEFAULT_HEIGHT</constant></term>
  84                 <listitem>
  85                     <para>
  86                         The value of <constant>GL_FRAMEBUFFER_DEFAULT_HEIGHT</constant> for the framebuffer is written to the
  87                         single integer variable whose address is given by <parameter>params</parameter>.
  88                     </para>
  89                 </listitem>
  90             </varlistentry>
  91             <varlistentry>
  92                 <term><constant>GL_FRAMEBUFFER_DEFAULT_LAYERS</constant></term>
  93                 <listitem>
  94                     <para>
  95                         The value of <constant>GL_FRAMEBUFFER_DEFAULT_LAYERS</constant> for the framebuffer is written to the
  96                         single integer variable whose address is given by <parameter>params</parameter>.
  97                     </para>
  98                 </listitem>
  99             </varlistentry>
 100             <varlistentry>
 101                 <term><constant>GL_FRAMEBUFFER_DEFAULT_SAMPLES</constant></term>
 102                 <listitem>
 103                     <para>
 104                         The value of <constant>GL_FRAMEBUFFER_DEFAULT_SAMPLES</constant> for the framebuffer is written to the
 105                         single integer variable whose address is given by <parameter>params</parameter>.
 106                     </para>
 107                 </listitem>
 108             </varlistentry>
 109             <varlistentry>
 110                 <term><constant>GL_FRAMEBUFFER_DEFAULT_FIXED_SAMPLE_LOCATIONS</constant></term>
 111                 <listitem>
 112                     <para>
 113                         If the value of <constant>GL_FRAMEBUFFER_DEFAULT_FIXED_SAMPLE_LOCATIONS</constant> for the framebuffer is <constant>GL_TRUE</constant>
 114                         then the single integer variable whose address is in <parameter>params</parameter> is set to one,
 115                         otherwise it is set to zero.
 116                     </para>
 117                 </listitem>
 118             </varlistentry>
 119         </variablelist>
 120     </refsect1>
 121     <refsect1 id="errors"><title>Errors</title>
 122         <para>
 123             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> is not one of the accepted
 124             framebuffer targets.
 125         </para>
 126         <para>
 127             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>pname</parameter> is not one of the accepted
 128             parameter names.
 129         </para>
 130         <para>
 131             <constant>GL_INVALID_OPERATION</constant> is generated if the default framebuffer is bound to <parameter>target</parameter>.
 132         </para>
 133         <para>
 134             <parameter>params</parameter> should be the address of a variable to which the client has write access otherwise
 135             undefined behavior, including process termination may occur.
 136         </para>
 137     </refsect1>
 138     <refsect1 id="associatedgets"><title>Associated Gets</title>
 139         <para>
 140             <citerefentry><refentrytitle>glGetFramebufferParameteriv</refentrytitle></citerefentry>.
 141         </para>
 142     </refsect1>
 143     <refsect1 id="seealso"><title>See Also</title>
 144         <para>
 145             <citerefentry><refentrytitle>glFramebufferParameteri</refentrytitle></citerefentry>.
 146         </para>
 147     </refsect1>
 148     <refsect1 id="Copyright"><title>Copyright</title>
 149         <para>
 150             Copyright <trademark class="copyright"></trademark> 2012 Khronos Group.
 151             This material may be distributed subject to the terms and conditions set forth in
 152             the Open Publication License, v 1.0, 8 June 1999.
 153             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 154         </para>
 155     </refsect1>
 156 </refentry>