upstream-doc/man3/glClearBuffer.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="glClearBuffer">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2010</year>
   9                 <holder>Khronos Group</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glClearBuffer</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glClearBuffer</refname>
  17         <refpurpose>clear individual buffers of the currently bound draw framebuffer</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glClearBufferiv</function></funcdef>
  23                 <paramdef>GLenum <parameter>buffer</parameter></paramdef>
  24                 <paramdef>GLint <parameter>drawBuffer</parameter></paramdef>
  25                 <paramdef>const GLint * <parameter>value</parameter></paramdef>
  26             </funcprototype>
  27         </funcsynopsis>
  28         <funcsynopsis>
  29             <funcprototype>
  30                 <funcdef>void <function>glClearBufferuiv</function></funcdef>
  31                 <paramdef>GLenum <parameter>buffer</parameter></paramdef>
  32                 <paramdef>GLint <parameter>drawBuffer</parameter></paramdef>
  33                 <paramdef>const GLuint * <parameter>value</parameter></paramdef>
  34             </funcprototype>
  35         </funcsynopsis>
  36         <funcsynopsis>
  37             <funcprototype>
  38                 <funcdef>void <function>glClearBufferfv</function></funcdef>
  39                 <paramdef>GLenum <parameter>buffer</parameter></paramdef>
  40                 <paramdef>GLint <parameter>drawBuffer</parameter></paramdef>
  41                 <paramdef>const GLfloat * <parameter>value</parameter></paramdef>
  42             </funcprototype>
  43         </funcsynopsis>
  44         <funcsynopsis>
  45             <funcprototype>
  46                 <funcdef>void <function>glClearBufferfi</function></funcdef>
  47                 <paramdef>GLenum <parameter>buffer</parameter></paramdef>
  48                 <paramdef>GLint <parameter>drawBuffer</parameter></paramdef>
  49                 <paramdef>GLfloat <parameter>depth</parameter></paramdef>
  50                 <paramdef>GLint <parameter>stencil</parameter></paramdef>
  51             </funcprototype>
  52         </funcsynopsis>
  53     </refsynopsisdiv>
  54     <refsect1 id="parameters"><title>Parameters</title>
  55         <variablelist>
  56         <varlistentry>
  57             <term><parameter>buffer</parameter></term>
  58             <listitem>
  59                 <para>
  60                     Specify the buffer to clear.
  61                 </para>
  62             </listitem>
  63         </varlistentry>
  64         <varlistentry>
  65             <term><parameter>drawBuffer</parameter></term>
  66             <listitem>
  67                 <para>
  68                     Specify a particular draw buffer to clear.
  69                 </para>
  70             </listitem>
  71         </varlistentry>
  72         <varlistentry>
  73             <term><parameter>value</parameter></term>
  74             <listitem>
  75                 <para>
  76                     For color buffers, a pointer to a four-element vector specifying R, G, B and A values to clear the buffer to.
  77                     For depth buffers, a pointer to a single depth value to clear the buffer to.
  78                     For stencil buffers, a pointer to a single stencil value to clear the buffer to.
  79                 </para>
  80             </listitem>
  81         </varlistentry>
  82         <varlistentry>
  83             <term><parameter>depth</parameter></term>
  84             <listitem>
  85                 <para>
  86                     The value to clear a depth render buffer to.
  87                 </para>
  88             </listitem>
  89         </varlistentry>
  90         <varlistentry>
  91             <term><parameter>stencil</parameter></term>
  92             <listitem>
  93                 <para>
  94                     The value to clear a stencil render buffer to.
  95                 </para>
  96             </listitem>
  97         </varlistentry>
  98         </variablelist>
  99     </refsect1>
 100     <refsect1 id="description"><title>Description</title>
 101         <para>
 102             <function>glClearBuffer*</function> clears the specified buffer to the specified value(s). If <parameter>buffer</parameter> is
 103             <constant>GL_COLOR</constant>, a particular draw buffer <constant>GL_DRAW_BUFFER<parameter>i</parameter></constant> is specified
 104             by passing <parameter>i</parameter> as <parameter>drawBuffer</parameter>. In this case, <parameter>value</parameter> points to
 105             a four-element vector specifying the R, G, B and A color to clear that draw buffer to. If <parameter>buffer</parameter> is
 106             one of <constant>GL_FRONT</constant>, <constant>GL_BACK</constant>, <constant>GL_LEFT</constant>, <constant>GL_RIGHT</constant>,
 107             or <constant>GL_FRONT_AND_BACK</constant>, identifying multiple buffers, each selected buffer is cleared to the same value.
 108             Clamping and conversion for fixed-point color buffers are performed in the same fashion as
 109             <citerefentry><refentrytitle>glClearColor</refentrytitle></citerefentry>.
 110         </para>
 111         <para>
 112             If <parameter>buffer</parameter> is <constant>GL_DEPTH</constant>, <parameter>drawBuffer</parameter> must be zero, and <parameter>value</parameter>
 113             points to a single value to clear the depth buffer to. Only <function>glClearBufferfv</function> should be used to clear
 114             depth buffers. Clamping and conversion for fixed-point depth buffers are performed in the same fashion as
 115             <citerefentry><refentrytitle>glClearDepth</refentrytitle></citerefentry>.
 116         </para>
 117         <para>
 118             If <parameter>buffer</parameter> is <constant>GL_STENCIL</constant>, <parameter>drawBuffer</parameter> must be zero, and <parameter>value</parameter>
 119             points to a single value to clear the stencil buffer to. Only <function>glClearBufferiv</function> should be used to clear
 120             stencil buffers. Masking and type conversion are performed in the same fashion as
 121             <citerefentry><refentrytitle>glClearStencil</refentrytitle></citerefentry>.
 122         </para>
 123         <para>
 124             <function>glClearBufferfi</function> may be used to clear the depth and stencil buffers. <parameter>buffer</parameter> must be
 125             <constant>GL_DEPTH_STENCIL</constant> and <parameter>drawBuffer</parameter> must be zero. <parameter>depth</parameter> and
 126             <parameter>stencil</parameter> are the depth and stencil values, respectively.
 127         </para>
 128         <para>
 129             The result of <function>glClearBuffer</function> is undefined if no conversion between the type of <parameter>value</parameter>
 130             and the buffer being cleared is defined. However, this is not an error.
 131         </para>
 132     </refsect1>
 133     <refsect1 id="errors"><title>Errors</title>
 134         <para>
 135             <constant>GL_INVALID_ENUM</constant> is generated by <function>glClearBufferif</function>, <function>glClearBufferfv</function>
 136             and <function>glClearBufferuiv</function> if <parameter>buffer</parameter> is not <constant>GL_COLOR</constant>,
 137             <constant>GL_FRONT</constant>, <constant>GL_BACK</constant>, <constant>GL_LEFT</constant>, <constant>GL_RIGHT</constant>,
 138             <constant>GL_FRONT_AND_BACK</constant>, <constant>GL_DEPTH</constant> or <constant>GL_STENCIL</constant>.
 139         </para>
 140         <para>
 141             <constant>GL_INVALID_ENUM</constant> is generated by <function>glClearBufferfi</function> if <parameter>buffer</parameter>
 142             is not <constant>GL_DEPTH_STENCIL</constant>.
 143         </para>
 144         <para>
 145             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>buffer</parameter> is <constant>GL_COLOR</constant>,
 146             <constant>GL_FRONT</constant>, <constant>GL_BACK</constant>, <constant>GL_LEFT</constant>, <constant>GL_RIGHT</constant>,
 147             or <constant>GL_FRONT_AND_BACK</constant> and <parameter>drawBuffer</parameter> is greater than or equal to <constant>GL_MAX_DRAW_BUFFERS</constant>.
 148         </para>
 149         <para>
 150             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>buffer</parameter> is <constant>GL_DEPTH</constant>,
 151              <constant>GL_STENCIL</constant> or <constant>GL_DEPTH_STENCIL</constant> and <parameter>drawBuffer</parameter> is not zero.
 152         </para>
 153     </refsect1>
 154     <refsect1 id="seealso"><title>See Also</title>
 155         <para>
 156             <citerefentry><refentrytitle>glClearColor</refentrytitle></citerefentry>,
 157             <citerefentry><refentrytitle>glClearDepth</refentrytitle></citerefentry>,
 158             <citerefentry><refentrytitle>glClearStencil</refentrytitle></citerefentry>,
 159             <citerefentry><refentrytitle>glClear</refentrytitle></citerefentry>
 160         </para>
 161     </refsect1>
 162     <refsect1 id="Copyright"><title>Copyright</title>
 163         <para>
 164             Copyright <trademark class="copyright"></trademark> 2010 Khronos Group.
 165             This material may be distributed subject to the terms and conditions set forth in
 166             the Open Publication License, v 1.0, 8 June 1999.
 167             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 168         </para>
 169     </refsect1>
 170 </refentry>