GLTEXPARAMETER
Section: [FIXME: manual] (3G)
Updated: 01/26/2021
Page Index
NAME
glTexParameter, glTextureParameter - set texture parameters
C SPECIFICATION
-
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);
PARAMETERS
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.
DESCRIPTION
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
Rt
and the stencil component will be discarded. If the depth stencil mode is
GL_STENCIL_COMPONENT
then the stencil component is returned in
Rt
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
0.0 , 0.0 , 0.0 , 0.0.
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:
f = 2 c + 1 2 b - 1. 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
|
result
=
1.0
0.0
r
<=
D
t
r
>
D
t
|
|
GL_GEQUAL
|
result
=
1.0
0.0
r
>=
D
t
r
<
D
t
|
|
GL_LESS
|
result
=
1.0
0.0
r
<
D
t
r
>=
D
t
|
|
GL_GREATER
|
result
=
1.0
0.0
r
>
D
t
r
<=
D
t
|
|
GL_EQUAL
|
result
=
1.0
0.0
r
=
D
t
r
≠
D
t
|
|
GL_NOTEQUAL
|
result
=
1.0
0.0
r
≠
D
t
r
=
D
t
|
|
GL_ALWAYS
|
result
=
1.0
|
|
GL_NEVER
|
result
=
0.0
|
where
r
is the current interpolated texture coordinate, and
D t
is the depth texture value sampled from the currently bound depth texture.
result
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
r
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
- bias max bias max, where
bias max
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
2 n × 2 m, there are
max n m + 1
mipmaps. The first mipmap is the original texture, with dimensions
2 n × 2 m. Each subsequent mipmap has dimensions
2 k - 1 × 2 l - 1, where
2 k × 2 l
are the dimensions of the previous mipmap, until either
k = 0
or
l = 0. At that point, subsequent mipmaps have dimension
1 × 2 l - 1
or
2 k - 1 × 1
until the final mipmap, which has dimension
1 × 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
max n m
is the final
1 × 1
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
r
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
r
will be taken from the first channel of the fetched texel. If
GL_TEXTURE_SWIZZLE_R
is
GL_GREEN, the value for
r
will be taken from the second channel of the fetched texel. If
GL_TEXTURE_SWIZZLE_R
is
GL_BLUE, the value for
r
will be taken from the third channel of the fetched texel. If
GL_TEXTURE_SWIZZLE_R
is
GL_ALPHA, the value for
r
will be taken from the fourth channel of the fetched texel. If
GL_TEXTURE_SWIZZLE_R
is
GL_ZERO, the value for
r
will be subtituted with
0.0. If
GL_TEXTURE_SWIZZLE_R
is
GL_ONE, the value for
r
will be subtituted with
1.0. The initial value is
GL_RED.
GL_TEXTURE_SWIZZLE_G
-
Sets the swizzle that will be applied to the
g
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
b
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
a
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
r,
g,
b, and
a
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
s
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
s
coordinates to be clamped to the range
1 2N 1 - 1 2N, where
N
is the size of the texture in the direction of clamping.
GL_CLAMP_TO_BORDER
evaluates
s
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
s
coordinate to be ignored; the GL uses only the fractional part, thereby creating a repeating pattern.
GL_MIRRORED_REPEAT
causes the
s
coordinate to be set to the fractional part of the texture coordinate if the integer part of
s
is even; if the integer part of
s
is odd, then the
s
texture coordinate is set to
1 - frac s, where
frac s
represents the fractional part of
s.
GL_MIRROR_CLAMP_TO_EDGE
causes the
s
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
t
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
r
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.
NOTES
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.
ERRORS
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.
ASSOCIATED GETS
glGetTexParameter()
glGetTextureParameter
glGetTexLevelParameter()
glGetTextureLevelParameter
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
|
|
glTexParameterIiv
|
-
|
-
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
|
glTexParameterIuiv
|
-
|
-
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
|
glTexParameterf
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
|
glTexParameterfv
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
|
glTexParameteri
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
|
glTexParameteriv
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
✔
|
|
glTextureParameterIiv
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
✔
|
|
glTextureParameterIuiv
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
✔
|
|
glTextureParameterf
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
✔
|
|
glTextureParameterfv
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
✔
|
|
glTextureParameteri
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
✔
|
|
glTextureParameteriv
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
✔
|
SEE ALSO
glActiveTexture(),
glBindTexture(),
glCopyTexImage1D(),
glCopyTexImage2D(),
glCopyTexSubImage1D(),
glCopyTexSubImage2D(),
glCopyTexSubImage3D(),
glPixelStore(),
glSamplerParameter(),
glTexImage1D(),
glTexImage2D(),
glTexImage3D(),
glTexSubImage1D(),
glTexSubImage2D(),
glTexSubImage3D()
COPYRIGHT
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
m[blue]http://oss.sgi.com/projects/FreeB/m[].
COPYRIGHT
Copyright © 1991-2006 Silicon Graphics, Inc.
Copyright © 2012-2014 Khronos Group