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=
"glClearIndex">
9 <holder>Silicon Graphics, Inc.
</holder>
12 <refentrytitle>glClearIndex
</refentrytitle>
13 <manvolnum>3G
</manvolnum>
16 <refname>glClearIndex
</refname>
17 <refpurpose>specify the clear value for the color index buffers
</refpurpose>
19 <refsynopsisdiv><title>C Specification
</title>
22 <funcdef>void
<function>glClearIndex
</function></funcdef>
23 <paramdef>GLfloat
<parameter>c
</parameter></paramdef>
27 <!-- eqn: ignoring delim $$ -->
28 <refsect1 id=
"parameters"><title>Parameters
</title>
31 <term><parameter>c
</parameter></term>
34 Specifies the index used when the color index buffers are cleared.
35 The initial value is
0.
41 <refsect1 id=
"description"><title>Description
</title>
43 <function>glClearIndex
</function> specifies the index used by
<citerefentry><refentrytitle>glClear
</refentrytitle></citerefentry>
44 to clear the color index buffers.
45 <parameter>c
</parameter> is not clamped.
47 <parameter>c
</parameter> is converted to a fixed-point value with unspecified precision
48 to the right of the binary point.
49 The integer part of this value is then masked with
50 <inlineequation><mml:math>
51 <!-- eqn: 2 sup m - 1:-->
53 <mml:msup><mml:mn>2</mml:mn>
54 <mml:mi mathvariant=
"italic">m
</mml:mi>
59 </mml:math></inlineequation>,
61 <inlineequation><mml:math><mml:mi mathvariant=
"italic">m
</mml:mi></mml:math></inlineequation>
62 is the number of bits in a color index stored in the frame buffer.
65 <refsect1 id=
"errors"><title>Errors
</title>
67 <constant>GL_INVALID_OPERATION
</constant> is generated if
<function>glClearIndex
</function>
68 is executed between the execution of
<citerefentry><refentrytitle>glBegin
</refentrytitle></citerefentry>
69 and the corresponding execution of
<citerefentry><refentrytitle>glEnd
</refentrytitle></citerefentry>.
72 <refsect1 id=
"associatedgets"><title>Associated Gets
</title>
74 <citerefentry><refentrytitle>glGet
</refentrytitle></citerefentry> with argument
<constant>GL_INDEX_CLEAR_VALUE
</constant>
77 <citerefentry><refentrytitle>glGet
</refentrytitle></citerefentry> with argument
<constant>GL_INDEX_BITS
</constant>
80 <refsect1 id=
"seealso"><title>See Also
</title>
82 <citerefentry><refentrytitle>glClear
</refentrytitle></citerefentry>
85 <refsect1 id=
"Copyright"><title>Copyright
</title>
87 Copyright
<trademark class=
"copyright"></trademark> 1991-
2006
88 Silicon Graphics, Inc. This document is licensed under the SGI
89 Free Software B License. For details, see
90 <ulink url=
"http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/
</ulink>.