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);

PARAMETERS

       target
           Specifies the symbolic name of the target texture, one of 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.

       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

       glGetTexLevelParameter returns in params texture parameter values for a specific
       level-of-detail value, specified as level.  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.

       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, 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_ENUM is generated 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 2max, 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.

SEE ALSO

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

COPYRIGHT

       Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2010-2013 Khronos Group. This
       document is licensed under the SGI Free Software B License. For details, see
       http://oss.sgi.com/projects/FreeB/.

AUTHORS

       opengl.org