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=
"glGetTexGen">
9 <holder>Silicon Graphics, Inc.
</holder>
12 <refentrytitle>glGetTexGen
</refentrytitle>
13 <manvolnum>3G
</manvolnum>
16 <refname>glGetTexGen
</refname>
17 <refpurpose>return texture coordinate generation parameters
</refpurpose>
19 <refsynopsisdiv><title>C Specification
</title>
22 <funcdef>void
<function>glGetTexGendv
</function></funcdef>
23 <paramdef>GLenum
<parameter>coord
</parameter></paramdef>
24 <paramdef>GLenum
<parameter>pname
</parameter></paramdef>
25 <paramdef>GLdouble *
<parameter>params
</parameter></paramdef>
30 <funcdef>void
<function>glGetTexGenfv
</function></funcdef>
31 <paramdef>GLenum
<parameter>coord
</parameter></paramdef>
32 <paramdef>GLenum
<parameter>pname
</parameter></paramdef>
33 <paramdef>GLfloat *
<parameter>params
</parameter></paramdef>
38 <funcdef>void
<function>glGetTexGeniv
</function></funcdef>
39 <paramdef>GLenum
<parameter>coord
</parameter></paramdef>
40 <paramdef>GLenum
<parameter>pname
</parameter></paramdef>
41 <paramdef>GLint *
<parameter>params
</parameter></paramdef>
45 <!-- eqn: ignoring delim $$ -->
46 <refsect1 id=
"parameters"><title>Parameters
</title>
49 <term><parameter>coord
</parameter></term>
52 Specifies a texture coordinate.
54 <constant>GL_S
</constant>,
55 <constant>GL_T
</constant>,
56 <constant>GL_R
</constant>, or
57 <constant>GL_Q
</constant>.
62 <term><parameter>pname
</parameter></term>
65 Specifies the symbolic name of the value(s) to be returned.
66 Must be either
<constant>GL_TEXTURE_GEN_MODE
</constant>
67 or the name of one of the texture generation plane equations:
68 <constant>GL_OBJECT_PLANE
</constant> or
<constant>GL_EYE_PLANE
</constant>.
73 <term><parameter>params
</parameter></term>
76 Returns the requested data.
82 <refsect1 id=
"description"><title>Description
</title>
84 <function>glGetTexGen
</function> returns in
<parameter>params
</parameter> selected parameters of a texture coordinate
85 generation function that was specified using
<citerefentry><refentrytitle>glTexGen
</refentrytitle></citerefentry>.
86 <parameter>coord
</parameter> names one of the (
<emphasis>s
</emphasis>,
<emphasis>t
</emphasis>,
<emphasis>r
</emphasis>,
<emphasis>q
</emphasis>)
88 using the symbolic constant
89 <constant>GL_S
</constant>,
90 <constant>GL_T
</constant>,
91 <constant>GL_R
</constant>, or
92 <constant>GL_Q
</constant>.
95 <parameter>pname
</parameter> specifies one of three symbolic names:
99 <term><constant>GL_TEXTURE_GEN_MODE
</constant></term>
102 <parameter>params
</parameter> returns the single-valued texture generation function,
103 a symbolic constant. The initial value is
<constant>GL_EYE_LINEAR
</constant>.
108 <term><constant>GL_OBJECT_PLANE
</constant></term>
111 <parameter>params
</parameter> returns the four plane equation coefficients that specify
112 object linear-coordinate generation.
113 Integer values, when requested,
114 are mapped directly from the internal floating-point representation.
119 <term><constant>GL_EYE_PLANE
</constant></term>
122 <parameter>params
</parameter> returns the four plane equation coefficients that specify
123 eye linear-coordinate generation.
126 are mapped directly from the internal floating-point representation.
127 The returned values are those maintained in eye coordinates.
128 They are not equal to the values specified using
<citerefentry><refentrytitle>glTexGen
</refentrytitle></citerefentry>,
129 unless the modelview matrix was identity when
<citerefentry><refentrytitle>glTexGen
</refentrytitle></citerefentry> was called.
135 <refsect1 id=
"notes"><title>Notes
</title>
137 If an error is generated,
138 no change is made to the contents of
<parameter>params
</parameter>.
141 For OpenGL versions
1.3 and greater, or when the
<code>ARB_multitexture
</code> extension is supported,
<function>glGetTexGen
</function> returns
142 the texture coordinate generation parameters for the active texture unit.
145 <refsect1 id=
"errors"><title>Errors
</title>
147 <constant>GL_INVALID_ENUM
</constant> is generated if
<parameter>coord
</parameter> or
<parameter>pname
</parameter> is not an
151 <constant>GL_INVALID_OPERATION
</constant> is generated if
<function>glGetTexGen
</function>
152 is executed between the execution of
<citerefentry><refentrytitle>glBegin
</refentrytitle></citerefentry>
153 and the corresponding execution of
<citerefentry><refentrytitle>glEnd
</refentrytitle></citerefentry>.
156 <refsect1 id=
"seealso"><title>See Also
</title>
158 <citerefentry><refentrytitle>glActiveTexture
</refentrytitle></citerefentry>,
159 <citerefentry><refentrytitle>glTexGen
</refentrytitle></citerefentry>
162 <refsect1 id=
"Copyright"><title>Copyright
</title>
164 Copyright
<trademark class=
"copyright"></trademark> 1991-
2006
165 Silicon Graphics, Inc. This document is licensed under the SGI
166 Free Software B License. For details, see
167 <ulink url=
"http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/
</ulink>.