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renderer=
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"Content-Type" content=
"text/html; charset=UTF-8" /><title>glGetTexEnv
</title><meta name=
"generator" content=
"DocBook XSL Stylesheets V1.73.2" /></head><body><div class=
"refentry" lang=
"en" xml:
lang=
"en"><a id=
"glGetTexEnv"></a><div class=
"titlepage"></div><div class=
"refnamediv"><h2>Name
</h2><p>glGetTexEnv — return texture environment parameters
</p></div><div class=
"refsynopsisdiv"><h2>C Specification
</h2><div class=
"funcsynopsis"><table border=
"0" summary=
"Function synopsis" cellspacing=
"0" cellpadding=
"0"><tr><td><code class=
"funcdef">void
<b class=
"fsfunc">glGetTexEnvfv
</b>(
</code></td><td>GLenum
</td><td><var class=
"pdparam">target
</var>,
</td></tr><tr><td> </td><td>GLenum
</td><td><var class=
"pdparam">pname
</var>,
</td></tr><tr><td> </td><td>GLfloat *
</td><td><var class=
"pdparam">params
</var><code>)
</code>;
</td></tr></table></div><p></p><div class=
"funcsynopsis"><table border=
"0" summary=
"Function synopsis" cellspacing=
"0" cellpadding=
"0"><tr><td><code class=
"funcdef">void
<b class=
"fsfunc">glGetTexEnviv
</b>(
</code></td><td>GLenum
</td><td><var class=
"pdparam">target
</var>,
</td></tr><tr><td> </td><td>GLenum
</td><td><var class=
"pdparam">pname
</var>,
</td></tr><tr><td> </td><td>GLint *
</td><td><var class=
"pdparam">params
</var><code>)
</code>;
</td></tr></table></div></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"parameters"></a><h2>Parameters
</h2><div class=
"variablelist"><dl><dt><span class=
"term"><em class=
"parameter"><code>target
</code></em></span></dt><dd><p>
4 Specifies a texture environment. May be
5 <code class=
"constant">GL_TEXTURE_ENV
</code>,
6 <code class=
"constant">GL_TEXTURE_FILTER_CONTROL
</code>, or
7 <code class=
"constant">GL_POINT_SPRITE
</code>.
8 </p></dd><dt><span class=
"term"><em class=
"parameter"><code>pname
</code></em></span></dt><dd><p>
9 Specifies the symbolic name of a texture environment parameter.
10 Accepted values are
<code class=
"constant">GL_TEXTURE_ENV_MODE
</code>,
<code class=
"constant">GL_TEXTURE_ENV_COLOR
</code>,
11 <code class=
"constant">GL_TEXTURE_LOD_BIAS
</code>,
12 <code class=
"constant">GL_COMBINE_RGB
</code>,
13 <code class=
"constant">GL_COMBINE_ALPHA
</code>,
14 <code class=
"constant">GL_SRC0_RGB
</code>,
15 <code class=
"constant">GL_SRC1_RGB
</code>,
16 <code class=
"constant">GL_SRC2_RGB
</code>,
17 <code class=
"constant">GL_SRC0_ALPHA
</code>,
18 <code class=
"constant">GL_SRC1_ALPHA
</code>,
19 <code class=
"constant">GL_SRC2_ALPHA
</code>,
20 <code class=
"constant">GL_OPERAND0_RGB
</code>,
21 <code class=
"constant">GL_OPERAND1_RGB
</code>,
22 <code class=
"constant">GL_OPERAND2_RGB
</code>,
23 <code class=
"constant">GL_OPERAND0_ALPHA
</code>,
24 <code class=
"constant">GL_OPERAND1_ALPHA
</code>,
25 <code class=
"constant">GL_OPERAND2_ALPHA
</code>,
26 <code class=
"constant">GL_RGB_SCALE
</code>,
27 <code class=
"constant">GL_ALPHA_SCALE
</code>, or
28 <code class=
"constant">GL_COORD_REPLACE
</code>.
29 </p></dd><dt><span class=
"term"><em class=
"parameter"><code>params
</code></em></span></dt><dd><p>
30 Returns the requested data.
31 </p></dd></dl></div></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"description"></a><h2>Description
</h2><p>
32 <code class=
"function">glGetTexEnv
</code> returns in
<em class=
"parameter"><code>params
</code></em> selected values of a texture environment that
33 was specified with
<a class=
"citerefentry" href=
"glTexEnv.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glTexEnv
</span></span></a>.
34 <em class=
"parameter"><code>target
</code></em> specifies a texture environment.
36 When
<em class=
"parameter"><code>target
</code></em> is
<code class=
"constant">GL_TEXTURE_FILTER_CONTROL
</code>,
37 <em class=
"parameter"><code>pname
</code></em> must be
<code class=
"constant">GL_TEXTURE_LOD_BIAS
</code>.
38 When
<em class=
"parameter"><code>target
</code></em> is
<code class=
"constant">GL_POINT_SPRITE
</code>,
39 <em class=
"parameter"><code>pname
</code></em> must be
<code class=
"constant">GL_COORD_REPLACE
</code>.
40 When
<em class=
"parameter"><code>target
</code></em> is
41 <code class=
"constant">GL_TEXTURE_ENV
</code>,
<em class=
"parameter"><code>pname
</code></em> can be
<code class=
"constant">GL_TEXTURE_ENV_MODE
</code>,
42 <code class=
"constant">GL_TEXTURE_ENV_COLOR
</code>,
<code class=
"constant">GL_COMBINE_RGB
</code>,
<code class=
"constant">GL_COMBINE_ALPHA
</code>,
43 <code class=
"constant">GL_RGB_SCALE
</code>,
<code class=
"constant">GL_ALPHA_SCALE
</code>,
44 <code class=
"constant">GL_SRC0_RGB
</code>,
<code class=
"constant">GL_SRC1_RGB
</code>,
<code class=
"constant">GL_SRC2_RGB
</code>,
45 <code class=
"constant">GL_SRC0_ALPHA
</code>,
<code class=
"constant">GL_SRC1_ALPHA
</code>, or
<code class=
"constant">GL_SRC2_ALPHA
</code>.
47 <em class=
"parameter"><code>pname
</code></em> names a specific texture environment parameter, as follows:
48 </p><div class=
"variablelist"><dl><dt><span class=
"term"><code class=
"constant">GL_TEXTURE_ENV_MODE
</code></span></dt><dd><p>
49 <em class=
"parameter"><code>params
</code></em> returns the single-valued texture environment mode,
50 a symbolic constant. The initial value is
<code class=
"constant">GL_MODULATE
</code>.
51 </p></dd><dt><span class=
"term"><code class=
"constant">GL_TEXTURE_ENV_COLOR
</code></span></dt><dd><p>
52 <em class=
"parameter"><code>params
</code></em> returns four integer or floating-point values that are the
53 texture environment color.
56 are linearly mapped from the internal floating-point representation
57 such that
1.0 maps to the most positive representable integer,
59 <mml:math xmlns:
mml=
"http://www.w3.org/1998/Math/MathML" overflow=
"scroll">
63 maps to the most negative representable integer. The initial
64 value is (
0,
0,
0,
0).
65 </p></dd><dt><span class=
"term"><code class=
"constant">GL_TEXTURE_LOD_BIAS
</code></span></dt><dd><p>
66 <em class=
"parameter"><code>params
</code></em> returns a single floating-point value that is the texture
67 level-of-detail bias. The initial value is
0.
68 </p></dd><dt><span class=
"term"><code class=
"constant">GL_COMBINE_RGB
</code></span></dt><dd><p>
69 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the current
70 RGB combine mode. The initial value is
<code class=
"constant">GL_MODULATE
</code>.
71 </p></dd><dt><span class=
"term"><code class=
"constant">GL_COMBINE_ALPHA
</code></span></dt><dd><p>
72 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the current
73 alpha combine mode. The initial value is
<code class=
"constant">GL_MODULATE
</code>.
74 </p></dd><dt><span class=
"term"><code class=
"constant">GL_SRC0_RGB
</code></span></dt><dd><p>
75 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the texture
76 combiner zero's RGB source. The initial value is
<code class=
"constant">GL_TEXTURE
</code>.
77 </p></dd><dt><span class=
"term"><code class=
"constant">GL_SRC1_RGB
</code></span></dt><dd><p>
78 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the texture
79 combiner one's RGB source. The initial value is
<code class=
"constant">GL_PREVIOUS
</code>.
80 </p></dd><dt><span class=
"term"><code class=
"constant">GL_SRC2_RGB
</code></span></dt><dd><p>
81 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the texture
82 combiner two's RGB source. The initial value is
<code class=
"constant">GL_CONSTANT
</code>.
83 </p></dd><dt><span class=
"term"><code class=
"constant">GL_SRC0_ALPHA
</code></span></dt><dd><p>
84 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the texture
85 combiner zero's alpha source. The initial value is
<code class=
"constant">GL_TEXTURE
</code>.
86 </p></dd><dt><span class=
"term"><code class=
"constant">GL_SRC1_ALPHA
</code></span></dt><dd><p>
87 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the texture
88 combiner one's alpha source. The initial value is
<code class=
"constant">GL_PREVIOUS
</code>.
89 </p></dd><dt><span class=
"term"><code class=
"constant">GL_SRC2_ALPHA
</code></span></dt><dd><p>
90 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the texture
91 combiner two's alpha source. The initial value is
<code class=
"constant">GL_CONSTANT
</code>.
92 </p></dd><dt><span class=
"term"><code class=
"constant">GL_OPERAND0_RGB
</code></span></dt><dd><p>
93 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the texture
94 combiner zero's RGB operand. The initial value is
<code class=
"constant">GL_SRC_COLOR
</code>.
95 </p></dd><dt><span class=
"term"><code class=
"constant">GL_OPERAND1_RGB
</code></span></dt><dd><p>
96 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the texture
97 combiner one's RGB operand. The initial value is
<code class=
"constant">GL_SRC_COLOR
</code>.
98 </p></dd><dt><span class=
"term"><code class=
"constant">GL_OPERAND2_RGB
</code></span></dt><dd><p>
99 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the texture
100 combiner two's RGB operand. The initial value is
<code class=
"constant">GL_SRC_ALPHA
</code>.
101 </p></dd><dt><span class=
"term"><code class=
"constant">GL_OPERAND0_ALPHA
</code></span></dt><dd><p>
102 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the texture
103 combiner zero's alpha operand. The initial value is
<code class=
"constant">GL_SRC_ALPHA
</code>.
104 </p></dd><dt><span class=
"term"><code class=
"constant">GL_OPERAND1_ALPHA
</code></span></dt><dd><p>
105 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the texture
106 combiner one's alpha operand. The initial value is
<code class=
"constant">GL_SRC_ALPHA
</code>.
107 </p></dd><dt><span class=
"term"><code class=
"constant">GL_OPERAND2_ALPHA
</code></span></dt><dd><p>
108 <em class=
"parameter"><code>params
</code></em> returns a single symbolic constant value representing the texture
109 combiner two's alpha operand. The initial value is
<code class=
"constant">GL_SRC_ALPHA
</code>.
110 </p></dd><dt><span class=
"term"><code class=
"constant">GL_RGB_SCALE
</code></span></dt><dd><p>
111 <em class=
"parameter"><code>params
</code></em> returns a single floating-point value representing the current RGB
112 texture combiner scaling factor. The initial value is
1.0.
113 </p></dd><dt><span class=
"term"><code class=
"constant">GL_ALPHA_SCALE
</code></span></dt><dd><p>
114 <em class=
"parameter"><code>params
</code></em> returns a single floating-point value representing the current alpha
115 texture combiner scaling factor. The initial value is
1.0.
116 </p></dd><dt><span class=
"term"><code class=
"constant">GL_COORD_REPLACE
</code></span></dt><dd><p>
117 <em class=
"parameter"><code>params
</code></em> returns a single boolean value representing the current point sprite
118 texture coordinate replacement enable state. The initial value is
<code class=
"constant">GL_FALSE
</code>.
119 </p></dd></dl></div></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"notes"></a><h2>Notes
</h2><p>
120 If an error is generated,
121 no change is made to the contents of
<em class=
"parameter"><code>params
</code></em>.
123 For OpenGL versions
1.3 and greater, or when the
<code class=
"code">ARB_multitexture
</code> extension is supported,
<code class=
"function">glGetTexEnv
</code> returns
124 the texture environment parameters for the active texture unit.
126 <code class=
"constant">GL_COMBINE_RGB
</code>,
127 <code class=
"constant">GL_COMBINE_ALPHA
</code>,
128 <code class=
"constant">GL_SRC0_RGB
</code>,
129 <code class=
"constant">GL_SRC1_RGB
</code>,
130 <code class=
"constant">GL_SRC2_RGB
</code>,
131 <code class=
"constant">GL_SRC0_ALPHA
</code>,
132 <code class=
"constant">GL_SRC1_ALPHA
</code>,
133 <code class=
"constant">GL_SRC2_ALPHA
</code>,
134 <code class=
"constant">GL_OPERAND0_RGB
</code>,
135 <code class=
"constant">GL_OPERAND1_RGB
</code>,
136 <code class=
"constant">GL_OPERAND2_RGB
</code>,
137 <code class=
"constant">GL_OPERAND0_ALPHA
</code>,
138 <code class=
"constant">GL_OPERAND1_ALPHA
</code>,
139 <code class=
"constant">GL_OPERAND2_ALPHA
</code>,
140 <code class=
"constant">GL_RGB_SCALE
</code>, and
141 <code class=
"constant">GL_ALPHA_SCALE
</code> are available only if the GL version is
1.3 or greater.
143 <code class=
"constant">GL_TEXTURE_FILTER_CONTROL
</code> and
<code class=
"constant">GL_TEXTURE_LOD_BIAS
</code> are available
144 only if the GL version is
1.4 or greater.
146 <code class=
"constant">GL_POINT_SPRITE
</code> and
<code class=
"constant">GL_COORD_REPLACE
</code> are available
147 only if the GL version is
2.0 or greater.
148 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"errors"></a><h2>Errors
</h2><p>
149 <code class=
"constant">GL_INVALID_ENUM
</code> is generated if
<em class=
"parameter"><code>target
</code></em> or
<em class=
"parameter"><code>pname
</code></em> is not an
152 <code class=
"constant">GL_INVALID_OPERATION
</code> is generated if
<code class=
"function">glGetTexEnv
</code>
153 is executed between the execution of
<a class=
"citerefentry" href=
"glBegin.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glBegin
</span></span></a>
154 and the corresponding execution of
<a class=
"citerefentry" href=
"glEnd.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glEnd
</span></span></a>.
155 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"seealso"></a><h2>See Also
</h2><p>
156 <a class=
"citerefentry" href=
"glActiveTexture.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glActiveTexture
</span></span></a>,
157 <a class=
"citerefentry" href=
"glTexEnv.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glTexEnv
</span></span></a>
158 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"Copyright"></a><h2>Copyright
</h2><p>
159 Copyright
<span class=
"trademark"></span>©
1991-
2006
160 Silicon Graphics, Inc. This document is licensed under the SGI
161 Free Software B License. For details, see
162 <a class=
"ulink" href=
"http://oss.sgi.com/projects/FreeB/" target=
"_top">http://oss.sgi.com/projects/FreeB/
</a>.
163 </p></div></div></body></html>