Specifies the sampler object whose parameter to modify.

Specifies the symbolic name of a sampler parameter. pname can be one of the following: GL_TEXTURE_WRAP_S, GL_TEXTURE_WRAP_T, GL_TEXTURE_WRAP_R, GL_TEXTURE_MIN_FILTER, GL_TEXTURE_MAG_FILTER, GL_TEXTURE_BORDER_COLOR, GL_TEXTURE_MIN_LOD, GL_TEXTURE_MAX_LOD, GL_TEXTURE_LOD_BIAS GL_TEXTURE_COMPARE_MODE, or GL_TEXTURE_COMPARE_FUNC.

For the scalar commands, specifies the value of pname.

For the vector commands (glSamplerParameter*v), specifies a pointer to an array where the value or values of pname are stored.

The texture minifying function is used whenever the pixel being textured maps to an area greater than one texture element. There are six defined minifying functions. Two of them use the nearest one or nearest four texture elements to compute the texture value. The other four use mipmaps.

A mipmap is an ordered set of arrays representing the same image at progressively lower resolutions. If the texture has dimensions $2^{\mathit{n}}\times 2^{\mathit{m}}$, there are $\mathit{max}\left(\mathit{n},\mathit{m}\right)+1$ mipmaps. The first mipmap is the original texture, with dimensions $2^{\mathit{n}}\times 2^{\mathit{m}}$. Each subsequent mipmap has dimensions $2^{\mathit{k}-1}\times 2^{\mathit{l}-1}$, where $2^{\mathit{k}}\times 2^{\mathit{l}}$ are the dimensions of the previous mipmap, until either $\mathit{k}=0$ or $\mathit{l}=0$. At that point, subsequent mipmaps have dimension $1\times 2^{\mathit{l}-1}$ or $2^{\mathit{k}-1}\times 1$ until the final mipmap, which has dimension $1\times 1$. To define the mipmaps, call glTexImage1D, glTexImage2D, glTexImage3D, glCopyTexImage1D, or glCopyTexImage2D with the level argument indicating the order of the mipmaps. Level 0 is the original texture; level $\mathit{max}\left(\mathit{n},\mathit{m}\right)$ is the final $1\times 1$ mipmap.

params supplies a function for minifying the texture as one of the following:

As more texture elements are sampled in the minification process, fewer aliasing artifacts will be apparent. While the GL_NEAREST and GL_LINEAR minification functions can be faster than the other four, they sample only one or four texture elements to determine the texture value of the pixel being rendered and can produce moire patterns or ragged transitions. The initial value of GL_TEXTURE_MIN_FILTER is GL_NEAREST_MIPMAP_LINEAR.

The texture magnification function is used when the pixel being textured maps to an area less than or equal to one texture element. It sets the texture magnification function to either GL_NEAREST or GL_LINEAR (see below). GL_NEAREST is generally faster than GL_LINEAR, but it can produce textured images with sharper edges because the transition between texture elements is not as smooth. The initial value of GL_TEXTURE_MAG_FILTER is GL_LINEAR.

Sets the minimum level-of-detail parameter. This floating-point value limits the selection of highest resolution mipmap (lowest mipmap level). The initial value is -1000.

Sets the maximum level-of-detail parameter. This floating-point value limits the selection of the lowest resolution mipmap (highest mipmap level). The initial value is 1000.

Sets the wrap parameter for texture coordinate $\mathit{s}$ to either GL_CLAMP_TO_EDGE, GL_MIRRORED_REPEAT, GL_REPEAT, or GL_MIRROR_CLAMP_TO_EDGE. GL_CLAMP_TO_BORDER causes the $\mathit{s}$ coordinate to be clamped to the range $\left[\frac{-1}{2\mathit{N}},1+\frac{1}{2\mathit{N}}\right]$, where $\mathit{N}$ is the size of the texture in the direction of clamping.GL_CLAMP_TO_EDGE causes $\mathit{s}$ coordinates to be clamped to the range $\left[\frac{1}{2\mathit{N}},1-\frac{1}{2\mathit{N}}\right]$, where $\mathit{N}$ is the size of the texture in the direction of clamping. GL_REPEAT causes the integer part of the $\mathit{s}$ coordinate to be ignored; the GL uses only the fractional part, thereby creating a repeating pattern. GL_MIRRORED_REPEAT causes the $\mathit{s}$ coordinate to be set to the fractional part of the texture coordinate if the integer part of $\mathit{s}$ is even; if the integer part of $\mathit{s}$ is odd, then the $\mathit{s}$ texture coordinate is set to $1-\mathit{frac}\left(\mathit{s}\right)$, where $\mathit{frac}\left(\mathit{s}\right)$ represents the fractional part of $\mathit{s}$. GL_MIRROR_CLAMP_TO_EDGE causes the the $\mathit{s}$ coordinate to be repeated as for GL_MIRRORED_REPEAT for one reptition of the texture, at which point the coordinate to be clamped as in GL_CLAMP_TO_EDGE. Initially, GL_TEXTURE_WRAP_S is set to GL_REPEAT.

Sets the wrap parameter for texture coordinate $\mathit{t}$ to either GL_CLAMP_TO_EDGE, GL_MIRRORED_REPEAT, GL_REPEAT, or GL_MIRROR_CLAMP_TO_EDGE. See the discussion under GL_TEXTURE_WRAP_S. Initially, GL_TEXTURE_WRAP_T is set to GL_REPEAT.

Sets the wrap parameter for texture coordinate $\mathit{r}$ to either GL_CLAMP_TO_EDGE, GL_MIRRORED_REPEAT, GL_REPEAT, or GL_MIRROR_CLAMP_TO_EDGE. See the discussion under GL_TEXTURE_WRAP_S. Initially, GL_TEXTURE_WRAP_R is set to GL_REPEAT.

The data in params specifies four values that define the border values that should be used for border texels. If a texel is sampled from the border of the texture, the values of GL_TEXTURE_BORDER_COLOR are interpreted as an RGBA color to match the texture's internal format and substituted for the non-existent texel data. If the texture contains depth components, the first component of GL_TEXTURE_BORDER_COLOR is interpreted as a depth value. The initial value is $\left(0.0,0.0,0.0,0.0\right)$.

Specifies the texture comparison mode for currently bound textures. That is, a texture whose internal format is GL_DEPTH_COMPONENT_*; see glTexImage2D) Permissible values are:

Specifies the comparison operator used when GL_TEXTURE_COMPARE_MODE is set to GL_COMPARE_REF_TO_TEXTURE. Permissible values are:

where $\mathit{r}$ is the current interpolated texture coordinate, and ${\mathit{D}}_{\mathit{t}}$ is the texture value sampled from the currently bound texture. $\mathit{result}$ is assigned to ${\mathit{R}}_{\mathit{t}}$.