glTexParameter, glTextureParameter — set texture parameters
void glTexParameterf(
|
GLenum target, |
| GLenum pname, | |
GLfloat param); |
void glTexParameteri(
|
GLenum target, |
| GLenum pname, | |
GLint param); |
void glTextureParameterf(
|
GLuint texture, |
| GLenum pname, | |
GLfloat param); |
void glTextureParameteri(
|
GLuint texture, |
| GLenum pname, | |
GLint param); |
void glTexParameterfv(
|
GLenum target, |
| GLenum pname, | |
const GLfloat * params); |
void glTexParameteriv(
|
GLenum target, |
| GLenum pname, | |
const GLint * params); |
void glTexParameterIiv(
|
GLenum target, |
| GLenum pname, | |
const GLint * params); |
void glTexParameterIuiv(
|
GLenum target, |
| GLenum pname, | |
const GLuint * params); |
void glTextureParameterfv(
|
GLuint texture, |
| GLenum pname, | |
const GLfloat *params); |
void glTextureParameteriv(
|
GLuint texture, |
| GLenum pname, | |
const GLint *params); |
void glTextureParameterIiv(
|
GLuint texture, |
| GLenum pname, | |
const GLint *params); |
void glTextureParameterIuiv(
|
GLuint texture, |
| GLenum pname, | |
const GLuint *params); |
target
Specifies the target to which the texture is bound for
glTexParameter functions. Must be one of
GL_TEXTURE_1D,
GL_TEXTURE_1D_ARRAY,
GL_TEXTURE_2D,
GL_TEXTURE_2D_ARRAY,
GL_TEXTURE_2D_MULTISAMPLE,
GL_TEXTURE_2D_MULTISAMPLE_ARRAY,
GL_TEXTURE_3D,
GL_TEXTURE_CUBE_MAP,
GL_TEXTURE_CUBE_MAP_ARRAY, or
GL_TEXTURE_RECTANGLE.
texture
Specifies the texture object name for
glTextureParameter functions.
pname
Specifies the symbolic name of a single-valued texture
parameter. pname can be one of the following:
GL_DEPTH_STENCIL_TEXTURE_MODE,
GL_TEXTURE_BASE_LEVEL,
GL_TEXTURE_COMPARE_FUNC,
GL_TEXTURE_COMPARE_MODE,
GL_TEXTURE_LOD_BIAS,
GL_TEXTURE_MIN_FILTER,
GL_TEXTURE_MAG_FILTER,
GL_TEXTURE_MIN_LOD,
GL_TEXTURE_MAX_LOD,
GL_TEXTURE_MAX_LEVEL,
GL_TEXTURE_SWIZZLE_R,
GL_TEXTURE_SWIZZLE_G,
GL_TEXTURE_SWIZZLE_B,
GL_TEXTURE_SWIZZLE_A,
GL_TEXTURE_WRAP_S,
GL_TEXTURE_WRAP_T, or
GL_TEXTURE_WRAP_R.
For the vector commands
(glTexParameter*v),
pname can also be one of
GL_TEXTURE_BORDER_COLOR or
GL_TEXTURE_SWIZZLE_RGBA.
param
For the scalar commands, specifies the value of
pname.
params
For the vector commands, specifies a pointer to an array where
the value or values of pname are
stored.
glTexParameter and
glTextureParameter assign the value or values in
params to the texture parameter specified as
pname. For glTexParameter,
target defines the target texture, either
GL_TEXTURE_1D,
GL_TEXTURE_1D_ARRAY,
GL_TEXTURE_2D,
GL_TEXTURE_2D_ARRAY,
GL_TEXTURE_2D_MULTISAMPLE,
GL_TEXTURE_2D_MULTISAMPLE_ARRAY,
GL_TEXTURE_3D,
GL_TEXTURE_CUBE_MAP,
GL_TEXTURE_CUBE_MAP_ARRAY, or
GL_TEXTURE_RECTANGLE. The following symbols are
accepted in pname:
GL_DEPTH_STENCIL_TEXTURE_MODE
Specifies the mode used to read from depth-stencil format textures. params
must be one of GL_DEPTH_COMPONENT or GL_STENCIL_COMPONENT.
If the depth stencil mode is GL_DEPTH_COMPONENT, then reads from depth-stencil
format textures will return the depth component of the texel in
and the stencil component
will be discarded. If the depth stencil mode is GL_STENCIL_COMPONENT then
the stencil component is returned in
and the depth component is discarded. The initial value is GL_DEPTH_COMPONENT.
GL_TEXTURE_BASE_LEVEL
Specifies the index of the lowest defined mipmap level. This is an integer value. The initial value is 0.
GL_TEXTURE_BORDER_COLOR
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
.
If the values for GL_TEXTURE_BORDER_COLOR are specified with glTexParameterIiv
or glTexParameterIuiv, the values are stored unmodified with an internal data type of
integer. If specified with glTexParameteriv, they are converted to floating point with the following
equation:
.
If specified with glTexParameterfv, they are stored unmodified as floating-point values.
GL_TEXTURE_COMPARE_FUNC
Specifies the comparison operator used when GL_TEXTURE_COMPARE_MODE is
set to GL_COMPARE_REF_TO_TEXTURE. Permissible values are:
| Texture Comparison Function | Computed result |
|---|---|
GL_LEQUAL
|
|
GL_GEQUAL
|
|
GL_LESS
|
|
GL_GREATER
|
|
GL_EQUAL
|
|
GL_NOTEQUAL
|
|
GL_ALWAYS
|
|
GL_NEVER
|
where is the current interpolated texture coordinate, and is the depth texture value sampled from the currently bound depth texture. is assigned to the red channel.
GL_TEXTURE_COMPARE_MODE
Specifies the texture comparison mode for currently bound depth textures.
That is, a texture whose internal format is GL_DEPTH_COMPONENT_*; see
glTexImage2D)
Permissible values are:
GL_COMPARE_REF_TO_TEXTURE
Specifies that the interpolated and clamped
texture coordinate should
be compared to the value in the currently bound depth texture. See the
discussion of GL_TEXTURE_COMPARE_FUNC for details of how the comparison
is evaluated. The result of the comparison is assigned to the red channel.
GL_NONE
Specifies that the red channel should be assigned the appropriate value from the currently bound depth texture.
GL_TEXTURE_LOD_BIAS
params specifies a fixed bias value that is to be added to the level-of-detail
parameter for the texture before texture sampling. The specified value is added to the shader-supplied
bias value (if any) and subsequently clamped into the implementation-defined range
,
where
is the value of the implementation defined constant GL_MAX_TEXTURE_LOD_BIAS. The initial value is 0.0.
GL_TEXTURE_MIN_FILTER
The texture minifying function is used whenever the level-of-detail function used when sampling from the texture determines that the texture should be minified. There are six defined minifying functions. Two of them use either the nearest texture elements or a weighted average of multiple 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 , there are mipmaps. The first mipmap is the original texture, with dimensions . Each subsequent mipmap has dimensions , where are the dimensions of the previous mipmap, until either or . At that point, subsequent mipmaps have dimension or until the final mipmap, which has dimension . 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 is the final mipmap.
params supplies a function for minifying the texture as one of the
following:
GL_NEAREST
Returns the value of the texture element that is nearest (in Manhattan distance) to the specified texture coordinates.
GL_LINEAR
Returns the weighted average of the four texture elements
that are closest to the specified texture coordinates.
These can include items wrapped or repeated from other parts of a texture,
depending on the values of GL_TEXTURE_WRAP_S and GL_TEXTURE_WRAP_T,
and on the exact mapping.
GL_NEAREST_MIPMAP_NEAREST
Chooses the mipmap that most closely matches the size of the pixel
being textured and uses the GL_NEAREST criterion
(the texture element closest to the specified texture coordinates)
to produce a texture value.
GL_LINEAR_MIPMAP_NEAREST
Chooses the mipmap that most closely matches the size of the pixel
being textured and uses the GL_LINEAR criterion
(a weighted average of the four texture elements that are closest to the specified texture coordinates)
to produce a texture value.
GL_NEAREST_MIPMAP_LINEAR
Chooses the two mipmaps that most closely match the size of the pixel
being textured and uses the GL_NEAREST criterion
(the texture element closest to the specified texture coordinates )
to produce a texture value from each mipmap.
The final texture value is a weighted average of those two values.
GL_LINEAR_MIPMAP_LINEAR
Chooses the two mipmaps that most closely match the size of the pixel
being textured and uses the GL_LINEAR criterion
(a weighted average of the texture elements that are closest to the specified texture coordinates)
to produce a texture value from each mipmap.
The final texture value is a weighted average of those two values.
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 multiple 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.
GL_TEXTURE_MAG_FILTER
The texture magnification function is used whenever the level-of-detail function
used when sampling from the texture determines that the texture should be magified.
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.
GL_NEAREST
Returns the value of the texture element that is nearest (in Manhattan distance) to the specified texture coordinates.
GL_LINEAR
Returns the weighted average of the texture elements
that are closest to the specified texture coordinates.
These can include items wrapped or repeated from other parts of a texture,
depending on the values of GL_TEXTURE_WRAP_S and GL_TEXTURE_WRAP_T,
and on the exact mapping.
GL_TEXTURE_MIN_LOD
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.
GL_TEXTURE_MAX_LOD
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.
GL_TEXTURE_MAX_LEVEL
Sets the index of the highest defined mipmap level. This is an integer value. The initial value is 1000.
GL_TEXTURE_SWIZZLE_R
Sets the swizzle that will be applied to the
component of a texel before it is returned to the shader. Valid values for param are GL_RED,
GL_GREEN, GL_BLUE, GL_ALPHA, GL_ZERO and
GL_ONE.
If GL_TEXTURE_SWIZZLE_R is GL_RED, the value for
will be taken from the first
channel of the fetched texel.
If GL_TEXTURE_SWIZZLE_R is GL_GREEN, the value for
will be taken from the second
channel of the fetched texel.
If GL_TEXTURE_SWIZZLE_R is GL_BLUE, the value for
will be taken from the third
channel of the fetched texel.
If GL_TEXTURE_SWIZZLE_R is GL_ALPHA, the value for
will be taken from the fourth
channel of the fetched texel.
If GL_TEXTURE_SWIZZLE_R is GL_ZERO, the value for
will be subtituted with
.
If GL_TEXTURE_SWIZZLE_R is GL_ONE, the value for
will be subtituted with
.
The initial value is GL_RED.
GL_TEXTURE_SWIZZLE_G
Sets the swizzle that will be applied to the
component of a texel before it is returned to the shader. Valid values for param and their effects are similar to
those of GL_TEXTURE_SWIZZLE_R.
The initial value is GL_GREEN.
GL_TEXTURE_SWIZZLE_B
Sets the swizzle that will be applied to the
component of a texel before it is returned to the shader. Valid values for param and their effects are similar to
those of GL_TEXTURE_SWIZZLE_R.
The initial value is GL_BLUE.
GL_TEXTURE_SWIZZLE_A
Sets the swizzle that will be applied to the
component of a texel before it is returned to the shader. Valid values for param and their effects are similar to
those of GL_TEXTURE_SWIZZLE_R.
The initial value is GL_ALPHA.
GL_TEXTURE_SWIZZLE_RGBA
Sets the swizzles that will be applied to the
,
,
, and
components of a texel before they are returned to the shader. Valid values for params and their effects are similar to
those of GL_TEXTURE_SWIZZLE_R, except that all channels are specified simultaneously.
Setting the value of GL_TEXTURE_SWIZZLE_RGBA is equivalent (assuming no errors are generated) to
setting the parameters of each of GL_TEXTURE_SWIZZLE_R,
GL_TEXTURE_SWIZZLE_G,
GL_TEXTURE_SWIZZLE_B, and
GL_TEXTURE_SWIZZLE_A successively.
GL_TEXTURE_WRAP_S
Sets the wrap parameter for texture coordinate
to either GL_CLAMP_TO_EDGE, GL_CLAMP_TO_BORDER,
GL_MIRRORED_REPEAT,
GL_REPEAT, or GL_MIRROR_CLAMP_TO_EDGE. GL_CLAMP_TO_EDGE causes
coordinates to be clamped to the
range
,
where
is the size
of the texture in the direction of clamping.
GL_CLAMP_TO_BORDER evaluates coordinates in a similar manner to GL_CLAMP_TO_EDGE.
However, in cases where clamping would have occurred in GL_CLAMP_TO_EDGE mode, the fetched texel data
is substituted with the values specified by GL_TEXTURE_BORDER_COLOR.
GL_REPEAT causes the
integer part of the
coordinate to be ignored; the GL uses only the
fractional part, thereby creating a repeating pattern.
GL_MIRRORED_REPEAT causes the
coordinate to be set to the
fractional part of the texture coordinate if the integer part of
is
even; if the integer part of
is odd, then the
texture coordinate is
set to
,
where
represents the fractional part of
.
GL_MIRROR_CLAMP_TO_EDGE causes the
coordinate to be repeated as for GL_MIRRORED_REPEAT for one repetition 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.
GL_TEXTURE_WRAP_T
Sets the wrap parameter for texture coordinate
to either GL_CLAMP_TO_EDGE, GL_CLAMP_TO_BORDER,
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.
GL_TEXTURE_WRAP_R
Sets the wrap parameter for texture coordinate
to either GL_CLAMP_TO_EDGE, GL_CLAMP_TO_BORDER,
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.
Suppose that a program attempts to sample from a texture and has set
GL_TEXTURE_MIN_FILTER to one of the functions that
requires a mipmap. If either the dimensions of the texture images
currently defined (with previous calls to
glTexImage1D,
glTexImage2D,
glTexImage3D,
glCopyTexImage1D,
or
glCopyTexImage2D)
do not follow the proper sequence for mipmaps (described above), or
there are fewer texture images defined than are needed, or the set of
texture images have differing numbers of texture components, then the
texture is considered incomplete.
Linear filtering accesses the four nearest texture elements only in 2D textures. In 1D textures, linear filtering accesses the two nearest texture elements. In 3D textures, linear filtering accesses the eight nearest texture elements.
glTexParameter specifies the texture
parameters for the active texture unit, specified by calling
glActiveTexture.
glTextureParameter specifies the texture parameters
for the texture object with ID texture.
GL_DEPTH_STENCIL_TEXTURE_MODE is available only
if the GL version is 4.3 or greater.
GL_MIRROR_CLAMP_TO_EDGE is available only if
the GL version is 4.4 or greater.
GL_INVALID_ENUM is generated by
glTexParameter if target is
not one of the accepted defined values.
GL_INVALID_ENUM is generated if
pname is not one of the accepted defined
values.
GL_INVALID_ENUM is generated if
params should have a defined constant value (based
on the value of pname) and does not.
GL_INVALID_ENUM is generated if
glTexParameter{if} or
glTextureParameter{if} is called for a non-scalar
parameter (pname GL_TEXTURE_BORDER_COLOR or
GL_TEXTURE_SWIZZLE_RGBA).
GL_INVALID_ENUM is generated if the effective
target is either GL_TEXTURE_2D_MULTISAMPLE or
GL_TEXTURE_2D_MULTISAMPLE_ARRAY, and
pname is any of the sampler states.
GL_INVALID_ENUM is generated if the effective
target is GL_TEXTURE_RECTANGLE and either of pnames
GL_TEXTURE_WRAP_S or
GL_TEXTURE_WRAP_T is set to either
GL_MIRROR_CLAMP_TO_EDGE,
GL_MIRRORED_REPEAT or
GL_REPEAT.
GL_INVALID_ENUM is generated if the effective
target is GL_TEXTURE_RECTANGLE and pname
GL_TEXTURE_MIN_FILTER is set to a value other than
GL_NEAREST or GL_LINEAR (no
mipmap filtering is permitted).
GL_INVALID_OPERATION is generated if the
effective target is either GL_TEXTURE_2D_MULTISAMPLE
or GL_TEXTURE_2D_MULTISAMPLE_ARRAY, and pname
GL_TEXTURE_BASE_LEVEL is set to a value other than
zero.
GL_INVALID_OPERATION is generated by
glTextureParameter if texture is not the name of an
existing texture object.
GL_INVALID_OPERATION is generated if the
effective target is GL_TEXTURE_RECTANGLE and pname
GL_TEXTURE_BASE_LEVEL is set to any value other than
zero.
GL_INVALID_VALUE is generated if
pname is GL_TEXTURE_BASE_LEVEL
or GL_TEXTURE_MAX_LEVEL, and
param or params is
negative.
glGetTextureParameter
glGetTextureLevelParameter
| 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 |
glTexParameterIiv
|
- | - | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
glTexParameterIuiv
|
- | - | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
glTexParameterf
|
✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
glTexParameterfv
|
✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
glTexParameteri
|
✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
glTexParameteriv
|
✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
glTextureParameterIiv
|
- | - | - | - | - | - | - | - | - | - | - | ✔ |
glTextureParameterIuiv
|
- | - | - | - | - | - | - | - | - | - | - | ✔ |
glTextureParameterf
|
- | - | - | - | - | - | - | - | - | - | - | ✔ |
glTextureParameterfv
|
- | - | - | - | - | - | - | - | - | - | - | ✔ |
glTextureParameteri
|
- | - | - | - | - | - | - | - | - | - | - | ✔ |
glTextureParameteriv
|
- | - | - | - | - | - | - | - | - | - | - | ✔ |
glActiveTexture, glBindTexture, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3D, glPixelStore, glSamplerParameter, glTexImage1D, glTexImage2D, glTexImage3D, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D
Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2012-2014 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.