glGetTexEnvfv(3g)

1GLGETTEXENV(3G)                  OpenGL Manual                 GLGETTEXENV(3G)
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NAME

6       glGetTexEnv - return texture environment parameters
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C SPECIFICATION

9       void glGetTexEnvfv(GLenum target, GLenum pname, GLfloat * params);
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11       void glGetTexEnviv(GLenum target, GLenum pname, GLint * params);
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PARAMETERS

14       target
15           Specifies a texture environment. May be GL_TEXTURE_ENV,
16           GL_TEXTURE_FILTER_CONTROL, or GL_POINT_SPRITE.
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18       pname
19           Specifies the symbolic name of a texture environment parameter.
20           Accepted values are GL_TEXTURE_ENV_MODE, GL_TEXTURE_ENV_COLOR,
21           GL_TEXTURE_LOD_BIAS, GL_COMBINE_RGB, GL_COMBINE_ALPHA, GL_SRC0_RGB,
22           GL_SRC1_RGB, GL_SRC2_RGB, GL_SRC0_ALPHA, GL_SRC1_ALPHA,
23           GL_SRC2_ALPHA, GL_OPERAND0_RGB, GL_OPERAND1_RGB, GL_OPERAND2_RGB,
24           GL_OPERAND0_ALPHA, GL_OPERAND1_ALPHA, GL_OPERAND2_ALPHA,
25           GL_RGB_SCALE, GL_ALPHA_SCALE, or GL_COORD_REPLACE.
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27       params
28           Returns the requested data.
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DESCRIPTION

31       glGetTexEnv returns in params selected values of a texture environment
32       that was specified with glTexEnv().  target specifies a texture
33       environment.
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35       When target is GL_TEXTURE_FILTER_CONTROL, pname must be
36       GL_TEXTURE_LOD_BIAS. When target is GL_POINT_SPRITE, pname must be
37       GL_COORD_REPLACE. When target is GL_TEXTURE_ENV, pname can be
38       GL_TEXTURE_ENV_MODE, GL_TEXTURE_ENV_COLOR, GL_COMBINE_RGB,
39       GL_COMBINE_ALPHA, GL_RGB_SCALE, GL_ALPHA_SCALE, GL_SRC0_RGB,
40       GL_SRC1_RGB, GL_SRC2_RGB, GL_SRC0_ALPHA, GL_SRC1_ALPHA, or
41       GL_SRC2_ALPHA.
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43       pname names a specific texture environment parameter, as follows:
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45       GL_TEXTURE_ENV_MODE
46           params returns the single-valued texture environment mode, a
47           symbolic constant. The initial value is GL_MODULATE.
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49       GL_TEXTURE_ENV_COLOR
50           params returns four integer or floating-point values that are the
51           texture environment color. Integer values, when requested, are
52           linearly mapped from the internal floating-point representation
53           such that 1.0 maps to the most positive representable integer, and
54           -1.0 maps to the most negative representable integer. The initial
55           value is (0, 0, 0, 0).
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57       GL_TEXTURE_LOD_BIAS
58           params returns a single floating-point value that is the texture
59           level-of-detail bias. The initial value is 0.
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61       GL_COMBINE_RGB
62           params returns a single symbolic constant value representing the
63           current RGB combine mode. The initial value is GL_MODULATE.
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65       GL_COMBINE_ALPHA
66           params returns a single symbolic constant value representing the
67           current alpha combine mode. The initial value is GL_MODULATE.
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69       GL_SRC0_RGB
70           params returns a single symbolic constant value representing the
71           texture combiner zero's RGB source. The initial value is
72           GL_TEXTURE.
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74       GL_SRC1_RGB
75           params returns a single symbolic constant value representing the
76           texture combiner one's RGB source. The initial value is
77           GL_PREVIOUS.
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79       GL_SRC2_RGB
80           params returns a single symbolic constant value representing the
81           texture combiner two's RGB source. The initial value is
82           GL_CONSTANT.
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84       GL_SRC0_ALPHA
85           params returns a single symbolic constant value representing the
86           texture combiner zero's alpha source. The initial value is
87           GL_TEXTURE.
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89       GL_SRC1_ALPHA
90           params returns a single symbolic constant value representing the
91           texture combiner one's alpha source. The initial value is
92           GL_PREVIOUS.
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94       GL_SRC2_ALPHA
95           params returns a single symbolic constant value representing the
96           texture combiner two's alpha source. The initial value is
97           GL_CONSTANT.
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99       GL_OPERAND0_RGB
100           params returns a single symbolic constant value representing the
101           texture combiner zero's RGB operand. The initial value is
102           GL_SRC_COLOR.
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104       GL_OPERAND1_RGB
105           params returns a single symbolic constant value representing the
106           texture combiner one's RGB operand. The initial value is
107           GL_SRC_COLOR.
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109       GL_OPERAND2_RGB
110           params returns a single symbolic constant value representing the
111           texture combiner two's RGB operand. The initial value is
112           GL_SRC_ALPHA.
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114       GL_OPERAND0_ALPHA
115           params returns a single symbolic constant value representing the
116           texture combiner zero's alpha operand. The initial value is
117           GL_SRC_ALPHA.
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119       GL_OPERAND1_ALPHA
120           params returns a single symbolic constant value representing the
121           texture combiner one's alpha operand. The initial value is
122           GL_SRC_ALPHA.
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124       GL_OPERAND2_ALPHA
125           params returns a single symbolic constant value representing the
126           texture combiner two's alpha operand. The initial value is
127           GL_SRC_ALPHA.
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129       GL_RGB_SCALE
130           params returns a single floating-point value representing the
131           current RGB texture combiner scaling factor. The initial value is
132           1.0.
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134       GL_ALPHA_SCALE
135           params returns a single floating-point value representing the
136           current alpha texture combiner scaling factor. The initial value is
137           1.0.
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139       GL_COORD_REPLACE
140           params returns a single boolean value representing the current
141           point sprite texture coordinate replacement enable state. The
142           initial value is GL_FALSE.
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NOTES

145       If an error is generated, no change is made to the contents of params.
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147       For OpenGL versions 1.3 and greater, or when the ARB_multitexture
148       extension is supported, glGetTexEnv returns the texture environment
149       parameters for the active texture unit.
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151       GL_COMBINE_RGB, GL_COMBINE_ALPHA, GL_SRC0_RGB, GL_SRC1_RGB,
152       GL_SRC2_RGB, GL_SRC0_ALPHA, GL_SRC1_ALPHA, GL_SRC2_ALPHA,
153       GL_OPERAND0_RGB, GL_OPERAND1_RGB, GL_OPERAND2_RGB, GL_OPERAND0_ALPHA,
154       GL_OPERAND1_ALPHA, GL_OPERAND2_ALPHA, GL_RGB_SCALE, and GL_ALPHA_SCALE
155       are available only if the GL version is 1.3 or greater.
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157       GL_TEXTURE_FILTER_CONTROL and GL_TEXTURE_LOD_BIAS are available only if
158       the GL version is 1.4 or greater.
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160       GL_POINT_SPRITE and GL_COORD_REPLACE are available only if the GL
161       version is 2.0 or greater.
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ERRORS

164       GL_INVALID_ENUM is generated if target or pname is not an accepted
165       value.
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167       GL_INVALID_OPERATION is generated if glGetTexEnv is executed between
168       the execution of glBegin() and the corresponding execution of glEnd().
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COPYRIGHT

174       Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
175       under the SGI Free Software B License. For details, see
176       http://oss.sgi.com/projects/FreeB/.
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AUTHORS

179       opengl.org
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183opengl.org                        06/10/2014                   GLGETTEXENV(3G)