'\" t
.\"     Title: glGetTexLevelParameter
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 01/03/2018
.\"    Manual: [FIXME: manual]
.\"    Source: [FIXME: source]
.\"  Language: English
.\"
.TH "GLGETTEXLEVELPARAMET" "3G" "01/03/2018" "[FIXME: source]" "[FIXME: manual]"
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.SH "NAME"
glGetTexLevelParameter \- return texture parameter values for a specific level of detail
.SH "C SPECIFICATION"
.HP \w'void\ glGetTexLevelParameterfv('u
.BI "void glGetTexLevelParameterfv(GLenum\ " "target" ", GLint\ " "level" ", GLenum\ " "pname" ", GLfloat\ *\ " "params" ");"
.HP \w'void\ glGetTexLevelParameteriv('u
.BI "void glGetTexLevelParameteriv(GLenum\ " "target" ", GLint\ " "level" ", GLenum\ " "pname" ", GLint\ *\ " "params" ");"
.HP \w'void\ glGetTextureLevelParameterfv('u
.BI "void glGetTextureLevelParameterfv(GLuint\ " "texture" ", GLint\ " "level" ", GLenum\ " "pname" ", GLfloat\ *" "params" ");"
.HP \w'void\ glGetTextureLevelParameteriv('u
.BI "void glGetTextureLevelParameteriv(GLuint\ " "texture" ", GLint\ " "level" ", GLenum\ " "pname" ", GLint\ *" "params" ");"
.SH "PARAMETERS"
.PP
\fItarget\fR
.RS 4
Specifies the target to which the texture is bound for
\fBglGetTexLevelParameterfv\fR
and
\fBglGetTexLevelParameteriv\fR
functions\&. Must be one of the following values:
\fBGL_TEXTURE_1D\fR,
\fBGL_TEXTURE_2D\fR,
\fBGL_TEXTURE_3D\fR,
\fBGL_TEXTURE_1D_ARRAY\fR,
\fBGL_TEXTURE_2D_ARRAY\fR,
\fBGL_TEXTURE_RECTANGLE\fR,
\fBGL_TEXTURE_2D_MULTISAMPLE\fR,
\fBGL_TEXTURE_2D_MULTISAMPLE_ARRAY\fR,
\fBGL_TEXTURE_CUBE_MAP_POSITIVE_X\fR,
\fBGL_TEXTURE_CUBE_MAP_NEGATIVE_X\fR,
\fBGL_TEXTURE_CUBE_MAP_POSITIVE_Y\fR,
\fBGL_TEXTURE_CUBE_MAP_NEGATIVE_Y\fR,
\fBGL_TEXTURE_CUBE_MAP_POSITIVE_Z\fR,
\fBGL_TEXTURE_CUBE_MAP_NEGATIVE_Z\fR,
\fBGL_PROXY_TEXTURE_1D\fR,
\fBGL_PROXY_TEXTURE_2D\fR,
\fBGL_PROXY_TEXTURE_3D\fR,
\fBGL_PROXY_TEXTURE_1D_ARRAY\fR,
\fBGL_PROXY_TEXTURE_2D_ARRAY\fR,
\fBGL_PROXY_TEXTURE_RECTANGLE\fR,
\fBGL_PROXY_TEXTURE_2D_MULTISAMPLE\fR,
\fBGL_PROXY_TEXTURE_2D_MULTISAMPLE_ARRAY\fR,
\fBGL_PROXY_TEXTURE_CUBE_MAP\fR, or
\fBGL_TEXTURE_BUFFER\fR\&.
.RE
.PP
\fItexture\fR
.RS 4
Specifies the texture object name for
\fBglGetTextureLevelParameterfv\fR
and
\fBglGetTextureLevelParameteriv\fR
functions\&.
.RE
.PP
\fIlevel\fR
.RS 4
Specifies the level\-of\-detail number of the desired image\&. Level 0 is the base image level\&. Level
n
is the
nth mipmap reduction image\&.
.RE
.PP
\fIpname\fR
.RS 4
Specifies the symbolic name of a texture parameter\&.
\fBGL_TEXTURE_WIDTH\fR,
\fBGL_TEXTURE_HEIGHT\fR,
\fBGL_TEXTURE_DEPTH\fR,
\fBGL_TEXTURE_INTERNAL_FORMAT\fR,
\fBGL_TEXTURE_RED_SIZE\fR,
\fBGL_TEXTURE_GREEN_SIZE\fR,
\fBGL_TEXTURE_BLUE_SIZE\fR,
\fBGL_TEXTURE_ALPHA_SIZE\fR,
\fBGL_TEXTURE_DEPTH_SIZE\fR,
\fBGL_TEXTURE_COMPRESSED\fR,
\fBGL_TEXTURE_COMPRESSED_IMAGE_SIZE\fR, and
\fBGL_TEXTURE_BUFFER_OFFSET\fR
are accepted\&.
.RE
.PP
\fIparams\fR
.RS 4
Returns the requested data\&.
.RE
.SH "DESCRIPTION"
.PP
\fBglGetTexLevelParameterfv\fR,
\fBglGetTexLevelParameteriv\fR,
\fBglGetTextureLevelParameterfv\fR
and
\fBglGetTextureLevelParameteriv\fR
return in
\fIparams\fR
texture parameter values for a specific level\-of\-detail value, specified as
\fIlevel\fR\&. For the first two functions,
\fItarget\fR
defines the target texture, either
\fBGL_TEXTURE_1D\fR,
\fBGL_TEXTURE_2D\fR,
\fBGL_TEXTURE_3D\fR,
\fBGL_PROXY_TEXTURE_1D\fR,
\fBGL_PROXY_TEXTURE_2D\fR,
\fBGL_PROXY_TEXTURE_3D\fR,
\fBGL_TEXTURE_CUBE_MAP_POSITIVE_X\fR,
\fBGL_TEXTURE_CUBE_MAP_NEGATIVE_X\fR,
\fBGL_TEXTURE_CUBE_MAP_POSITIVE_Y\fR,
\fBGL_TEXTURE_CUBE_MAP_NEGATIVE_Y\fR,
\fBGL_TEXTURE_CUBE_MAP_POSITIVE_Z\fR,
\fBGL_TEXTURE_CUBE_MAP_NEGATIVE_Z\fR, or
\fBGL_PROXY_TEXTURE_CUBE_MAP\fR\&. The remaining two take a
\fItexture\fR
argument which specifies the name of the texture object\&.
.PP
\fBGL_MAX_TEXTURE_SIZE\fR, and
\fBGL_MAX_3D_TEXTURE_SIZE\fR
are not really descriptive enough\&. It has to report the largest square texture image that can be accommodated with mipmaps but a long skinny texture, or a texture without mipmaps may easily fit in texture memory\&. The proxy targets allow the user to more accurately query whether the GL can accommodate a texture of a given configuration\&. If the texture cannot be accommodated, the texture state variables, which may be queried with
\fBglGetTexLevelParameter\fR
and
\fBglGetTextureLevelParameter\fR, are set to 0\&. If the texture can be accommodated, the texture state values will be set as they would be set for a non\-proxy target\&.
.PP
\fIpname\fR
specifies the texture parameter whose value or values will be returned\&.
.PP
The accepted parameter names are as follows:
.PP
\fBGL_TEXTURE_WIDTH\fR
.RS 4
\fIparams\fR
returns a single value, the width of the texture image\&. The initial value is 0\&.
.RE
.PP
\fBGL_TEXTURE_HEIGHT\fR
.RS 4
\fIparams\fR
returns a single value, the height of the texture image\&. The initial value is 0\&.
.RE
.PP
\fBGL_TEXTURE_DEPTH\fR
.RS 4
\fIparams\fR
returns a single value, the depth of the texture image\&. The initial value is 0\&.
.RE
.PP
\fBGL_TEXTURE_INTERNAL_FORMAT\fR
.RS 4
\fIparams\fR
returns a single value, the internal format of the texture image\&.
.RE
.PP
\fBGL_TEXTURE_RED_TYPE\fR, \fBGL_TEXTURE_GREEN_TYPE\fR, \fBGL_TEXTURE_BLUE_TYPE\fR, \fBGL_TEXTURE_ALPHA_TYPE\fR, \fBGL_TEXTURE_DEPTH_TYPE\fR
.RS 4
The data type used to store the component\&. The types
\fBGL_NONE\fR,
\fBGL_SIGNED_NORMALIZED\fR,
\fBGL_UNSIGNED_NORMALIZED\fR,
\fBGL_FLOAT\fR,
\fBGL_INT\fR, and
\fBGL_UNSIGNED_INT\fR
may be returned to indicate signed normalized fixed\-point, unsigned normalized fixed\-point, floating\-point, integer unnormalized, and unsigned integer unnormalized components, respectively\&.
.RE
.PP
\fBGL_TEXTURE_RED_SIZE\fR, \fBGL_TEXTURE_GREEN_SIZE\fR, \fBGL_TEXTURE_BLUE_SIZE\fR, \fBGL_TEXTURE_ALPHA_SIZE\fR, \fBGL_TEXTURE_DEPTH_SIZE\fR
.RS 4
.sp
The internal storage resolution of an individual component\&. The resolution chosen by the GL will be a close match for the resolution requested by the user with the component argument of
\fBglTexImage1D\fR(),
\fBglTexImage2D\fR(),
\fBglTexImage3D\fR(),
\fBglCopyTexImage1D\fR(), and
\fBglCopyTexImage2D\fR()\&. The initial value is 0\&.
.RE
.PP
\fBGL_TEXTURE_COMPRESSED\fR
.RS 4
.sp
\fIparams\fR
returns a single boolean value indicating if the texture image is stored in a compressed internal format\&. The initiali value is
\fBGL_FALSE\fR\&.
.RE
.PP
\fBGL_TEXTURE_COMPRESSED_IMAGE_SIZE\fR
.RS 4
.sp
\fIparams\fR
returns a single integer value, the number of unsigned bytes of the compressed texture image that would be returned from
\fBglGetCompressedTexImage\fR()\&.
.RE
.PP
\fBGL_TEXTURE_BUFFER_OFFSET\fR
.RS 4
.sp
\fIparams\fR
returns a single integer value, the offset into the data store of the buffer bound to a buffer texture\&.
\fBglTexBufferRange\fR()\&.
.RE
.PP
\fBGL_TEXTURE_BUFFER_SIZE\fR
.RS 4
.sp
\fIparams\fR
returns a single integer value, the size of the range of a data store of the buffer bound to a buffer texture\&.
\fBglTexBufferRange\fR()\&.
.RE
.SH "NOTES"
.PP
If an error is generated, no change is made to the contents of
\fIparams\fR\&.
.PP
\fBglGetTexLevelParameter\fR
returns the texture level parameters for the active texture unit\&.
.PP
\fBGL_TEXTURE_BUFFER_OFFSET\fR
and
\fBGL_TEXTURE_BUFFER_SIZE\fR
are available only if the GL version is 4\&.3 or greater\&.
.SH "ERRORS"
.PP
\fBGL_INVALID_OPERATION\fR
is generated by
\fBglGetTextureLevelParameterfv\fR
and
\fBglGetTextureLevelParameteriv\fR
functions if
\fItexture\fR
is not the name of an existing texture object\&.
.PP
\fBGL_INVALID_ENUM\fR
is generated by
\fBglGetTexLevelParameterfv\fR
and
\fBglGetTexLevelParameteriv\fR
functions if
\fItarget\fR
or
\fIpname\fR
is not an accepted value\&.
.PP
\fBGL_INVALID_VALUE\fR
is generated if
\fIlevel\fR
is less than 0\&.
.PP
\fBGL_INVALID_VALUE\fR
may be generated if
\fIlevel\fR
is greater than
log 2
\fImax\fR, where
\fImax\fR
is the returned value of
\fBGL_MAX_TEXTURE_SIZE\fR\&.
.PP
\fBGL_INVALID_VALUE\fR
is generated if
\fItarget\fR
is
\fBGL_TEXTURE_BUFFER\fR
and
\fIlevel\fR
is not zero\&.
.PP
\fBGL_INVALID_OPERATION\fR
is generated if
\fBGL_TEXTURE_COMPRESSED_IMAGE_SIZE\fR
is queried on texture images with an uncompressed internal format or on proxy targets\&.
.SH "VERSION SUPPORT"
.TS
allbox tab(:);
lB cB s s s s s s s s s s s
lB cB cB cB cB cB cB cB cB cB cB cB cB.
T{

T}:T{
\fBOpenGL Version\fR
T}
T{
\fBFunction / Feature Name\fR
T}:T{
\fB2\&.0\fR
T}:T{
\fB2\&.1\fR
T}:T{
\fB3\&.0\fR
T}:T{
\fB3\&.1\fR
T}:T{
\fB3\&.2\fR
T}:T{
\fB3\&.3\fR
T}:T{
\fB4\&.0\fR
T}:T{
\fB4\&.1\fR
T}:T{
\fB4\&.2\fR
T}:T{
\fB4\&.3\fR
T}:T{
\fB4\&.4\fR
T}:T{
\fB4\&.5\fR
T}
.T&
l c c c c c c c c c c c c
l c c c c c c c c c c c c
l c c c c c c c c c c c c
l c c c c c c c c c c c c.
T{
\fBglGetTexLevelParameterfv\fR
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
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✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}
T{
\fBglGetTexLevelParameteriv\fR
T}:T{
✔
T}:T{
✔
T}:T{
✔
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✔
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✔
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✔
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✔
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✔
T}
T{
\fBglGetTextureLevelParameterfv\fR
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
✔
T}
T{
\fBglGetTextureLevelParameteriv\fR
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
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\-
T}:T{
\-
T}:T{
\-
T}:T{
✔
T}
.TE
.sp 1
.SH "SEE ALSO"
.PP
\fBglActiveTexture\fR(),
\fBglGetTexParameter\fR(),
\fBglCopyTexImage1D\fR(),
\fBglCopyTexImage2D\fR(),
\fBglCopyTexSubImage1D\fR(),
\fBglCopyTexSubImage2D\fR(),
\fBglCopyTexSubImage3D\fR(),
\fBglTexImage1D\fR(),
\fBglTexImage2D\fR(),
\fBglTexImage3D\fR(),
\fBglTexSubImage1D\fR(),
\fBglTexSubImage2D\fR(),
\fBglTexSubImage3D\fR(),
\fBglTexParameter\fR()
.SH "COPYRIGHT"
.PP
Copyright
\(co
1991\-2006 Silicon Graphics, Inc\&. Copyright
\(co
2010\-2014 Khronos Group\&. This document is licensed under the SGI Free Software B License\&. For details, see
\m[blue]\fBhttp://oss\&.sgi\&.com/projects/FreeB/\fR\m[]\&.
.SH "COPYRIGHT"
.br
Copyright \(co 2014 Khronos Group
.br