glGetTexLevelParameter(3gl)

1GLGETTEXLEVELPARAMETER(3G)                          GLGETTEXLEVELPARAMETER(3G)
2
3
4

NAME

6       glGetTexLevelParameterfv,  glGetTexLevelParameteriv  -  return  texture
7       parameter values for a specific level of detail
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9

C SPECIFICATION

11       void glGetTexLevelParameterfv( GLenum target,
12                                      GLint level,
13                                      GLenum pname,
14                                      GLfloat *params )
15       void glGetTexLevelParameteriv( GLenum target,
16                                      GLint level,
17                                      GLenum pname,
18                                      GLint *params )
19
20

PARAMETERS

22       target  Specifies the symbolic  name  of  the  target  texture,  either
23               GL_TEXTURE_1D,           GL_TEXTURE_2D,          GL_TEXTURE_3D,
24               GL_PROXY_TEXTURE_1D,          GL_PROXY_TEXTURE_2D,           or
25               GL_PROXY_TEXTURE_3D.
26
27       level   Specifies  the  level-of-detail  number  of  the desired image.
28               Level 0 is the base image level.  Level n  is  the  nth  mipmap
29               reduction image.
30
31       pname   Specifies   the   symbolic   name   of   a  texture  parameter.
32               GL_TEXTURE_WIDTH,     GL_TEXTURE_HEIGHT,      GL_TEXTURE_DEPTH,
33               GL_TEXTURE_INTERNAL_FORMAT,                  GL_TEXTURE_BORDER,
34               GL_TEXTURE_RED_SIZE,                     GL_TEXTURE_GREEN_SIZE,
35               GL_TEXTURE_BLUE_SIZE,                    GL_TEXTURE_ALPHA_SIZE,
36               GL_TEXTURE_LUMINANCE_SIZE,  and  GL_TEXTURE_INTENSITY_SIZE  are
37               accepted.
38
39       params  Returns the requested data.
40

DESCRIPTION

42       glGetTexLevelParameter returns in params texture parameter values for a
43       specific level-of-detail value, specified as level.  target defines the
44       target  texture,  either  GL_TEXTURE_1D,  GL_TEXTURE_2D, GL_TEXTURE_3D,
45       GL_PROXY_TEXTURE_1D, GL_PROXY_TEXTURE_2D, or GL_PROXY_TEXTURE_3D.
46
47       GL_MAX_TEXTURE_SIZE, and GL_MAX_3D_TEXTURE_SIZE are not really descrip‐
48       tive  enough.   It  has to report the largest square texture image that
49       can be accommodated with mipmaps and borders, but a  long  skinny  tex‐
50       ture,  or a texture without mipmaps and borders, may easily fit in tex‐
51       ture memory.  The proxy targets allow the user to more accurately query
52       whether  the GL can accommodate a texture of a given configuration.  If
53       the texture cannot be accommodated, the texture state variables,  which
54       may  be queried with glGetTexLevelParameter, are set to 0.  If the tex‐
55       ture can be accommodated, the texture state values will be set as  they
56       would be set for a non-proxy target.
57
58       pname  specifies  the  texture  parameter whose value or values will be
59       returned.
60
61       The accepted parameter names are as follows:
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63       GL_TEXTURE_WIDTH
64                 params returns a single  value,  the  width  of  the  texture
65                 image.   This value includes the border of the texture image.
66                 The initial value is 0.
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68       GL_TEXTURE_HEIGHT
69                 params returns a single value,  the  height  of  the  texture
70                 image.   This value includes the border of the texture image.
71                 The initial value is 0.
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73       GL_TEXTURE_DEPTH
74                 params returns a single  value,  the  depth  of  the  texture
75                 image.   This value includes the border of the texture image.
76                 The initial value is 0.
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78       GL_TEXTURE_INTERNAL_FORMAT
79                 params returns a single value, the internal  of  the  texture
80                 image.
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82       GL_TEXTURE_BORDER
83                 params  returns  a  single  value, the width in pixels of the
84                 border of the texture image. The initial value is 0.
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86       GL_TEXTURE_RED_SIZE,
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88       GL_TEXTURE_GREEN_SIZE,
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90       GL_TEXTURE_BLUE_SIZE,
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92       GL_TEXTURE_ALPHA_SIZE,
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94       GL_TEXTURE_LUMINANCE_SIZE,
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96       GL_TEXTURE_INTENSITY_SIZE
97                 The internal storage resolution of an  individual  component.
98                 The resolution chosen by the GL will be a close match for the
99                 resolution requested by the user with the component  argument
100                 of       glTexImage1D,       glTexImage2D,      glTexImage3D,
101                 glCopyTexImage1D, and glCopyTexImage2D. The initial value  is
102                 0.
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NOTES

105       If an error is generated, no change is made to the contents of params.
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107       GL_TEXTURE_INTERNAL_FORMAT  is  available only if the GL version is 1.1
108       or greater. In version 1.0, use GL_TEXTURE_COMPONENTS instead.
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110       GL_PROXY_TEXTURE_1D and GL_PROXY_TEXTURE_2D are available only  if  the
111       GL version is 1.1 or greater.
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113       GL_TEXTURE_3D,  GL_PROXY_TEXTURE_3D, and GL_TEXTURE_DEPTH are available
114       only if the GL version is 1.2 or greater.
115
116       When    the     GL_ARB_multitexture     extension     is     supported,
117       glGetTexLevelParameter  returns  the  texture  level parameters for the
118       active texture unit.
119

ERRORS

121       GL_INVALID_ENUM is generated if target or  pname  is  not  an  accepted
122       value.
123
124       GL_INVALID_VALUE is generated if level is less than 0.
125
126       GL_INVALID_VALUE  may  be  generated if level is greater than log2 max,
127       where max is the returned value of GL_MAX_TEXTURE_SIZE.
128
129       GL_INVALID_OPERATION is generated if glGetTexLevelParameter is executed
130       between  the  execution  of  glBegin and the corresponding execution of
131       glEnd.
132

NAME

C SPECIFICATION

PARAMETERS

DESCRIPTION

NOTES

ERRORS

SEE ALSO