glGetTexLevelParameter - OpenGL 4 Reference Pages

## Name

glGetTexLevelParameter — return texture parameter values for a specific level of detail

## C Specification

`void glGetTexLevelParameterfv(` | GLenum target,
| GLint level,
| GLenum pname,
| GLfloat * params`)`;

`void glGetTexLevelParameteriv(` | GLenum target,
| GLint level,
| GLenum pname,
| GLint * params`)`;

`void glGetTextureLevelParameterfv(` | GLuint texture,
| GLint level,
| GLenum pname,
| GLfloat *params`)`;

`void glGetTextureLevelParameteriv(` | GLuint texture,
| GLint level,
| GLenum pname,
| GLint *params`)`;

## Parameters

`target`

  Specifies the target to which the texture is bound for `glGetTexLevelParameterfv` and `glGetTexLevelParameteriv` functions. Must be one of the following values: `GL_TEXTURE_1D`, `GL_TEXTURE_2D`, `GL_TEXTURE_3D`, `GL_TEXTURE_1D_ARRAY`, `GL_TEXTURE_2D_ARRAY`, `GL_TEXTURE_RECTANGLE`, `GL_TEXTURE_2D_MULTISAMPLE`, `GL_TEXTURE_2D_MULTISAMPLE_ARRAY`, `GL_TEXTURE_CUBE_MAP_POSITIVE_X`, `GL_TEXTURE_CUBE_MAP_NEGATIVE_X`, `GL_TEXTURE_CUBE_MAP_POSITIVE_Y`, `GL_TEXTURE_CUBE_MAP_NEGATIVE_Y`, `GL_TEXTURE_CUBE_MAP_POSITIVE_Z`, `GL_TEXTURE_CUBE_MAP_NEGATIVE_Z`, `GL_PROXY_TEXTURE_1D`, `GL_PROXY_TEXTURE_2D`, `GL_PROXY_TEXTURE_3D`, `GL_PROXY_TEXTURE_1D_ARRAY`, `GL_PROXY_TEXTURE_2D_ARRAY`, `GL_PROXY_TEXTURE_RECTANGLE`, `GL_PROXY_TEXTURE_2D_MULTISAMPLE`, `GL_PROXY_TEXTURE_2D_MULTISAMPLE_ARRAY`, `GL_PROXY_TEXTURE_CUBE_MAP`, or `GL_TEXTURE_BUFFER`.

`texture`

  Specifies the texture object name for `glGetTextureLevelParameterfv` and `glGetTextureLevelParameteriv` functions.

`level`

  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.

`pname`

  Specifies the symbolic name of a texture parameter. `GL_TEXTURE_WIDTH`, `GL_TEXTURE_HEIGHT`, `GL_TEXTURE_DEPTH`, `GL_TEXTURE_INTERNAL_FORMAT`, `GL_TEXTURE_RED_SIZE`, `GL_TEXTURE_GREEN_SIZE`, `GL_TEXTURE_BLUE_SIZE`, `GL_TEXTURE_ALPHA_SIZE`, `GL_TEXTURE_DEPTH_SIZE`, `GL_TEXTURE_COMPRESSED`, `GL_TEXTURE_COMPRESSED_IMAGE_SIZE`, and `GL_TEXTURE_BUFFER_OFFSET` are accepted.

`params`

  Returns the requested data.

## Description

`glGetTexLevelParameterfv`, `glGetTexLevelParameteriv`, `glGetTextureLevelParameterfv` and `glGetTextureLevelParameteriv` return in `params` texture parameter values for a specific level-of-detail value, specified as `level`. For the first two functions, `target` defines the target texture, either `GL_TEXTURE_1D`, `GL_TEXTURE_2D`, `GL_TEXTURE_3D`, `GL_PROXY_TEXTURE_1D`, `GL_PROXY_TEXTURE_2D`, `GL_PROXY_TEXTURE_3D`, `GL_TEXTURE_CUBE_MAP_POSITIVE_X`, `GL_TEXTURE_CUBE_MAP_NEGATIVE_X`, `GL_TEXTURE_CUBE_MAP_POSITIVE_Y`, `GL_TEXTURE_CUBE_MAP_NEGATIVE_Y`, `GL_TEXTURE_CUBE_MAP_POSITIVE_Z`, `GL_TEXTURE_CUBE_MAP_NEGATIVE_Z`, or `GL_PROXY_TEXTURE_CUBE_MAP`. The remaining two take a `texture` argument which specifies the name of the texture object.

`GL_MAX_TEXTURE_SIZE`, and `GL_MAX_3D_TEXTURE_SIZE` 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 `glGetTexLevelParameter` and `glGetTextureLevelParameter`, 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.

`pname` specifies the texture parameter whose value or values will be returned.

The accepted parameter names are as follows:

`GL_TEXTURE_WIDTH`

  `params` returns a single value, the width of the texture image. The initial value is 0.

`GL_TEXTURE_HEIGHT`

  `params` returns a single value, the height of the texture image. The initial value is 0.

`GL_TEXTURE_DEPTH`

  `params` returns a single value, the depth of the texture image. The initial value is 0.

`GL_TEXTURE_INTERNAL_FORMAT`

  `params` returns a single value, the internal format of the texture image.

`GL_TEXTURE_RED_TYPE`, `GL_TEXTURE_GREEN_TYPE`, `GL_TEXTURE_BLUE_TYPE`, `GL_TEXTURE_ALPHA_TYPE`, `GL_TEXTURE_DEPTH_TYPE`

  The data type used to store the component. The types `GL_NONE`, `GL_SIGNED_NORMALIZED`, `GL_UNSIGNED_NORMALIZED`, `GL_FLOAT`, `GL_INT`, and `GL_UNSIGNED_INT` may be returned to indicate signed normalized fixed-point, unsigned normalized fixed-point, floating-point, integer unnormalized, and unsigned integer unnormalized components, respectively.

`GL_TEXTURE_RED_SIZE`, `GL_TEXTURE_GREEN_SIZE`, `GL_TEXTURE_BLUE_SIZE`, `GL_TEXTURE_ALPHA_SIZE`, `GL_TEXTURE_DEPTH_SIZE`

  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 glTexImage1D, glTexImage2D, glTexImage3D, glCopyTexImage1D, and glCopyTexImage2D. The initial value is 0.

`GL_TEXTURE_COMPRESSED`

  `params` returns a single boolean value indicating if the texture image is stored in a compressed internal format. The initiali value is `GL_FALSE`.

`GL_TEXTURE_COMPRESSED_IMAGE_SIZE`

  `params` returns a single integer value, the number of unsigned bytes of the compressed texture image that would be returned from glGetCompressedTexImage.

`GL_TEXTURE_BUFFER_OFFSET`

  `params` returns a single integer value, the offset into the data store of the buffer bound to a buffer texture. glTexBufferRange.

`GL_TEXTURE_BUFFER_SIZE`

  `params` returns a single integer value, the size of the range of a data store of the buffer bound to a buffer texture. glTexBufferRange.

## Notes

If an error is generated, no change is made to the contents of `params`.

`glGetTexLevelParameter` returns the texture level parameters for the active texture unit.

`GL_TEXTURE_BUFFER_OFFSET` and `GL_TEXTURE_BUFFER_SIZE` are available only if the GL version is 4.3 or greater.

## Errors

`GL_INVALID_OPERATION` is generated by `glGetTextureLevelParameterfv` and `glGetTextureLevelParameteriv` functions if `texture` is not the name of an existing texture object.

`GL_INVALID_ENUM` is generated by `glGetTexLevelParameterfv` and `glGetTexLevelParameteriv` functions if `target` or `pname` is not an accepted value.

`GL_INVALID_VALUE` is generated if `level` is less than 0.

`GL_INVALID_VALUE` may be generated if `level` is greater than log 2 max, where max is the returned value of `GL_MAX_TEXTURE_SIZE`.

`GL_INVALID_VALUE` is generated if `target` is `GL_TEXTURE_BUFFER` and `level` is not zero.

`GL_INVALID_OPERATION` is generated if `GL_TEXTURE_COMPRESSED_IMAGE_SIZE` is queried on texture images with an uncompressed internal format or on proxy targets.

## Version Support

| OpenGL Version
--- | ---
Function / Feature Name | 2.0 | 2.1 | 3.0 | 3.1 | 3.2 | 3.3 | 4.0 | 4.1 | 4.2 | 4.3 | 4.4 | 4.5
`glGetTexLevelParameterfv` | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔
`glGetTexLevelParameteriv` | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔
`glGetTextureLevelParameterfv` | - | - | - | - | - | - | - | - | - | - | - | ✔
`glGetTextureLevelParameteriv` | - | - | - | - | - | - | - | - | - | - | - | ✔

## See Also

glActiveTexture, glGetTexParameter, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3D, glTexImage1D, glTexImage2D, glTexImage3D, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D, glTexParameter

## Copyright

Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2010-2014 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.