glGetTexLevelParameter(3G)glGetTexLevelParameter(3G)NAME
glGetTexLevelParameter, glGetTexLevelParameterfv, glGetTexLevelParame‐
teriv - return texture parameter values for a specific level of detail
SYNOPSIS
void glGetTexLevelParameterfv(
GLenum target,
GLint level,
GLenum pname,
GLfloat *params ); void glGetTexLevelParameteriv(
GLenum target,
GLint level,
GLenum pname,
GLint *params );
PARAMETERS
Specifies the symbolic name of the target texture, either GL_TEX‐
TURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, GL_PROXY_TEXTURE_1D,
GL_PROXY_TEXTURE_2D, or GL_PROXY_TEXTURE_3D. 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. Specifies the symbolic name
of a texture parameter. GL_TEXTURE_WIDTH, GL_TEXTURE_HEIGHT, GL_TEX‐
TURE_DEPTH, GL_TEXTURE_INTERNAL_FORMAT, GL_TEXTURE_BORDER, GL_TEX‐
TURE_RED_SIZE, GL_TEXTURE_GREEN_SIZE, GL_TEXTURE_BLUE_SIZE, GL_TEX‐
TURE_ALPHA_SIZE, GL_TEXTURE_LUMINANCE_SIZE, and GL_TEXTURE_INTEN‐
SITY_SIZE are accepted. Returns the requested data.
DESCRIPTIONglGetTexLevelParameter() 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, or GL_PROXY_TEXTURE_3D.
GL_MAX_TEXTURE_SIZE, and GL_MAX_3D_TEXTURE_SIZE are not really descrip‐
tive enough. It has to report the largest square texture image that can
be accommodated with mipmaps and borders, but a long skinny texture, or
a texture without mipmaps and borders, may easily fit in texture mem‐
ory. The proxy targets allow the user to more accurately query whether
the GL can accommodate a texture of a given configuration. If the tex‐
ture 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: params returns a single
value, the width of the texture image. This value includes the border
of the texture image. The initial value is 0. params returns a single
value, the height of the texture image. This value includes the border
of the texture image. The initial value is 0. params returns a single
value, the depth of the texture image. This value includes the border
of the texture image. The initial value is 0. params returns a single
value, the internal of the texture image. params returns a single
value, the width in pixels of the border of the texture image. The ini‐
tial value is 0.
GL_TEXTURE_RED_SIZE
GL_TEXTURE_GREEN_SIZE
GL_TEXTURE_BLUE_SIZE
GL_TEXTURE_ALPHA_SIZE
GL_TEXTURE_LUMINANCE_SIZE
The internal storage resolution of an individual component. The resolu‐
tion 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 glCopyTexIm‐
age2D(). The initial value is 0.
NOTES
If an error is generated, no change is made to the contents of params.
GL_TEXTURE_INTERNAL_FORMAT is available only if the GL version is 1.1
or greater. In version 1.0, use GL_TEXTURE_COMPONENTS instead.
GL_PROXY_TEXTURE_1D and GL_PROXY_TEXTURE_2D are available only if the
GL version is 1.1 or greater.
GL_TEXTURE_3D, GL_PROXY_TEXTURE_3D, and GL_TEXTURE_DEPTH are available
only if the GL version is 1.2 or greater.
When the GL_ARB_multitexture extension is supported, glGetTexLevelPa‐
rameter() returns the texture level parameters for the active texture
unit.
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 sub 2
max, where max is the returned value of GL_MAX_TEXTURE_SIZE.
GL_INVALID_OPERATION is generated if glGetTexLevelParameter() is exe‐
cuted between the execution of glBegin() and the corresponding execu‐
tion of glEnd().
SEE ALSOglActiveTextureARB(3), glGetTexParameter(3), glCopyTexImage1D(3),
glCopyTexImage2D(3), glCopyTexSubImage1D(3), glCopyTexSubImage2D(3),
glCopyTexSubImage3D(3), glTexEnv(3), glTexGen(3), glTexImage1D(3),
glTexImage2D(3), glTexImage3D(3), glTexSubImage1D(3), glTexSubIm‐
age2D(3), glTexSubImage3D(3), glTexParameter(3)glGetTexLevelParameter(3G)
