upstream-doc/man2/glStencilMask.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="glStencilMask">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glStencilMask</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glStencilMask</refname>
  17         <refpurpose>control the front and back writing of individual bits in the stencil planes</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glStencilMask</function></funcdef>
  23                 <paramdef>GLuint <parameter>mask</parameter></paramdef>
  24             </funcprototype>
  25         </funcsynopsis>
  26     </refsynopsisdiv>
  27     <!-- eqn: ignoring delim $$ -->
  28     <refsect1 id="parameters"><title>Parameters</title>
  29         <variablelist>
  30         <varlistentry>
  31             <term><parameter>mask</parameter></term>
  32             <listitem>
  33                 <para>
  34                     Specifies a bit mask to enable and disable writing of individual bits
  35                     in the stencil planes.
  36                     Initially, the mask is all 1's.
  37                 </para>
  38             </listitem>
  39         </varlistentry>
  40         </variablelist>
  41     </refsect1>
  42     <refsect1 id="description"><title>Description</title>
  43         <para>
  44             <function>glStencilMask</function> controls the writing of individual bits in the stencil planes.
  45             The least significant
  46             <inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>
  47             bits of <parameter>mask</parameter>,
  48             where
  49             <inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>
  50             is the number of bits in the stencil buffer,
  51             specify a mask.
  52             Where a 1 appears in the mask,
  53             it's possible to write to the corresponding bit in the stencil buffer.
  54             Where a 0 appears,
  55             the corresponding bit is write-protected.
  56             Initially, all bits are enabled for writing.
  57         </para>
  58         <para>
  59             There can be two separate <parameter>mask</parameter> writemasks; one affects back-facing polygons, and the other
  60             affects front-facing polygons as well as other non-polygon primitives.
  61             <citerefentry><refentrytitle>glStencilMask</refentrytitle></citerefentry> sets both front
  62             and back stencil writemasks to the same values. Use <citerefentry><refentrytitle>glStencilMaskSeparate</refentrytitle></citerefentry>
  63             to set front and back stencil writemasks to different values.
  64         </para>
  65     </refsect1>
  66     <refsect1 id="notes"><title>Notes</title>
  67         <para>
  68             <citerefentry><refentrytitle>glStencilMask</refentrytitle></citerefentry> is the same as
  69             calling <citerefentry><refentrytitle>glStencilMaskSeparate</refentrytitle></citerefentry>
  70             with <parameter>face</parameter> set to <constant>GL_FRONT_AND_BACK</constant>.
  71         </para>
  72     </refsect1>
  73     <refsect1 id="errors"><title>Errors</title>
  74         <para>
  75             <constant>GL_INVALID_OPERATION</constant> is generated if <function>glStencilMask</function>
  76             is executed between the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry>
  77             and the corresponding execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
  78         </para>
  79     </refsect1>
  80     <refsect1 id="associatedgets"><title>Associated Gets</title>
  81         <para>
  82             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument
  83             <constant>GL_STENCIL_WRITEMASK</constant>, <constant>GL_STENCIL_BACK_WRITEMASK</constant>,
  84             or <constant>GL_STENCIL_BITS</constant>
  85         </para>
  86     </refsect1>
  87     <refsect1 id="seealso"><title>See Also</title>
  88         <para>
  89             <citerefentry><refentrytitle>glColorMask</refentrytitle></citerefentry>,
  90             <citerefentry><refentrytitle>glDepthMask</refentrytitle></citerefentry>,
  91             <citerefentry><refentrytitle>glIndexMask</refentrytitle></citerefentry>,
  92             <citerefentry><refentrytitle>glStencilFunc</refentrytitle></citerefentry>,
  93             <citerefentry><refentrytitle>glStencilFuncSeparate</refentrytitle></citerefentry>,
  94             <citerefentry><refentrytitle>glStencilMaskSeparate</refentrytitle></citerefentry>,
  95             <citerefentry><refentrytitle>glStencilOp</refentrytitle></citerefentry>,
  96             <citerefentry><refentrytitle>glStencilOpSeparate</refentrytitle></citerefentry>
  97         </para>
  98     </refsect1>
  99     <refsect1 id="Copyright"><title>Copyright</title>
 100         <para>
 101             Copyright <trademark class="copyright"></trademark> 1991-2006
 102             Silicon Graphics, Inc. This document is licensed under the SGI
 103             Free Software B License. For details, see
 104             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 105         </para>
 106     </refsect1>
 107 </refentry>