specify a two-dimensional texture image
Signature
glTexImage2D(
GLenum (
target
)
,
GLint (
level
)
,
GLint (
internalFormat
)
,
GLsizei (
width
)
,
GLsizei (
height
)
,
GLint (
border
)
,
GLenum (
format
)
,
GLenum (
type
)
,
const GLvoid * (
data
)
)-> void
glTexImage2D(
target
,
level
,
internalformat
,
width
,
height
,
border
,
format
,
type
,
pixels
)
glTexImage2D( GLenum(target), GLint(level), GLint(internalformat), GLsizei(width), GLsizei(height), GLint(border), GLenum(format), GLenum(type), POINTER(GLvoid)(pixels) ) -> None
glTexImage2Df(
target
,
level
,
internalformat
,
border
,
format
,
pixels
)
glTexImage2D( GLenum(target), GLint(level), GLint(internalformat), GLsizei(width), GLsizei(height), GLint(border), GLenum(format), GLenum(type), POINTER(GLvoid)(pixels) ) -> None
glTexImage2Di(
target
,
level
,
internalformat
,
border
,
format
,
pixels
)
glTexImage2D( GLenum(target), GLint(level), GLint(internalformat), GLsizei(width), GLsizei(height), GLint(border), GLenum(format), GLenum(type), POINTER(GLvoid)(pixels) ) -> None
glTexImage2Ds(
target
,
level
,
internalformat
,
border
,
format
,
pixels
)
glTexImage2D( GLenum(target), GLint(level), GLint(internalformat), GLsizei(width), GLsizei(height), GLint(border), GLenum(format), GLenum(type), POINTER(GLvoid)(pixels) ) -> None
Parameters
Description
Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is enabled. To enable and disable two-dimensional texturing, call
glEnable
and
glDisable
with argument
GL_TEXTURE_2D
. To enable and disable texturing using cube-mapped texture, call
glEnable
and
glDisable
with argument
GL_TEXTURE_CUBE_MAP
.
To define texture images, call
glTexImage2D
.
The arguments describe the parameters of the texture image,
such as height,
width,
width of the border,
level-of-detail number
(see
glTexParameter
),
and number of color components provided.
The last three arguments describe how the image is represented in memory;
they are identical to the pixel formats used for
glDrawPixels
.
If
target
is
GL_PROXY_TEXTURE_2D
or
GL_PROXY_TEXTURE_CUBE_MAP
, no data is read from
data
, but
all of the texture image state is recalculated, checked for
consistency, and checked
against the implementation's capabilities. If the implementation cannot
handle a texture of the requested texture size, it sets
all of the image state to 0,
but does not generate an error (see
glGetError
). To query for an
entire mipmap array, use an image array level greater than or equal to
1.
If
target
is
GL_TEXTURE_2D
, or one of the
GL_TEXTURE_CUBE_MAP
targets, data is read from
data
as a sequence of signed or unsigned
bytes, shorts, or longs, or single-precision floating-point values,
depending on
type
. These values are grouped into sets of one, two,
three, or four values, depending on
format
, to form elements. If
type
is
GL_BITMAP
, the data is considered as a string of unsigned bytes
(and
format
must be
GL_COLOR_INDEX
).
Each data byte is treated as eight 1-bit elements,
with bit ordering determined by
GL_UNPACK_LSB_FIRST
(see
glPixelStore
).
If a non-zero named buffer object is bound to the
GL_PIXEL_UNPACK_BUFFER
target
(see
glBindBuffer
) while a texture image is
specified,
data
is treated as a byte offset into the buffer object's data store.
The first element corresponds to the lower left corner of the texture
image.
Subsequent elements progress left-to-right through the remaining texels
in the lowest row of the texture image, and then in successively higher
rows of the texture image.
The final element corresponds to the upper right corner of the texture
image.
format
determines the composition of each element in
data
.
It can assume one of these symbolic values:
- GL_COLOR_INDEX
-
Each element is a single value, a color index. The GL converts it to fixed point (with an unspecified number of zero bits to the right of the binary point), shifted left or right depending on the value and sign of GL_INDEX_SHIFT , and added to GL_INDEX_OFFSET (see glPixelTransfer ). The resulting index is converted to a set of color components using the GL_PIXEL_MAP_I_TO_R , GL_PIXEL_MAP_I_TO_G , GL_PIXEL_MAP_I_TO_B , and GL_PIXEL_MAP_I_TO_A tables, and clamped to the range [0,1].
- GL_RED
-
Each element is a single red component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for green and blue, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE , added to the signed bias GL_c_BIAS , and clamped to the range [0,1] (see glPixelTransfer ).
- GL_GREEN
-
Each element is a single green component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red and blue, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE , added to the signed bias GL_c_BIAS , and clamped to the range [0,1] (see glPixelTransfer ).
- GL_BLUE
-
Each element is a single blue component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red and green, and 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE , added to the signed bias GL_c_BIAS , and clamped to the range [0,1] (see glPixelTransfer ).
- GL_ALPHA
-
Each element is a single alpha component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for red, green, and blue. Each component is then multiplied by the signed scale factor GL_c_SCALE , added to the signed bias GL_c_BIAS , and clamped to the range [0,1] (see glPixelTransfer ).
- GL_INTENSITY
-
Each element is a single intensity value. The GL converts it to floating point, then assembles it into an RGBA element by replicating the intensity value three times for red, green, blue, and alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE , added to the signed bias GL_c_BIAS , and clamped to the range [0,1] (see glPixelTransfer ).
- GL_RGB
- GL_BGR
-
Each element is an RGB triple. The GL converts it to floating point and assembles it into an RGBA element by attaching 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE , added to the signed bias GL_c_BIAS , and clamped to the range [0,1] (see glPixelTransfer ).
- GL_RGBA
- GL_BGRA
-
Each element contains all four components. Each component is multiplied by the signed scale factor GL_c_SCALE , added to the signed bias GL_c_BIAS , and clamped to the range [0,1] (see glPixelTransfer ).
- GL_LUMINANCE
-
Each element is a single luminance value. The GL converts it to floating point, then assembles it into an RGBA element by replicating the luminance value three times for red, green, and blue and attaching 1 for alpha. Each component is then multiplied by the signed scale factor GL_c_SCALE , added to the signed bias GL_c_BIAS , and clamped to the range [0,1] (see glPixelTransfer ).
- GL_LUMINANCE_ALPHA
-
Each element is a luminance/alpha pair. The GL converts it to floating point, then assembles it into an RGBA element by replicating the luminance value three times for red, green, and blue. Each component is then multiplied by the signed scale factor GL_c_SCALE , added to the signed bias GL_c_BIAS , and clamped to the range [0,1] (see glPixelTransfer ).
- GL_DEPTH_COMPONENT
-
Each element is a single depth value. The GL converts it to floating point, multiplies by the signed scale factor GL_DEPTH_SCALE , adds the signed bias GL_DEPTH_BIAS , and clamps to the range [0,1] (see glPixelTransfer ).
Refer to the
glDrawPixels
reference page for a description of
the acceptable values for the
type
parameter.
If an application wants to store the texture at a certain
resolution or in a certain format, it can request the resolution
and format with
internalFormat
. The GL will choose an internal
representation that closely approximates that requested by
internalFormat
, but
it may not match exactly.
(The representations specified by
GL_LUMINANCE
,
GL_LUMINANCE_ALPHA
,
GL_RGB
,
and
GL_RGBA
must match exactly. The numeric values 1, 2, 3, and 4
may also be used to specify the above representations.)
If the
internalFormat
parameter is one of the generic compressed formats,
GL_COMPRESSED_ALPHA
,
GL_COMPRESSED_INTENSITY
,
GL_COMPRESSED_LUMINANCE
,
GL_COMPRESSED_LUMINANCE_ALPHA
,
GL_COMPRESSED_RGB
, or
GL_COMPRESSED_RGBA
, the GL will replace the internal format with the symbolic constant for a specific internal format and compress the texture before storage. If no corresponding internal format is available, or the GL can not compress that image for any reason, the internal format is instead replaced with a corresponding base internal format.
If the
internalFormat
parameter is
GL_SRGB
,
GL_SRGB8
,
GL_SRGB_ALPHA
,
GL_SRGB8_ALPHA8
,
GL_SLUMINANCE
,
GL_SLUMINANCE8
,
GL_SLUMINANCE_ALPHA
, or
GL_SLUMINANCE8_ALPHA8
, the texture is treated as if the red, green, blue, or luminance components are encoded in the sRGB color space. Any alpha component is left unchanged. The conversion from the sRGB encoded component
to a linear component
is:
Assume
is the sRGB component in the range [0,1].
Use the
GL_PROXY_TEXTURE_2D
or
GL_PROXY_TEXTURE_CUBE_MAP
target to try out a resolution and
format. The implementation will
update and recompute its best match for the requested storage resolution
and format. To then query this state, call
glGetTexLevelParameter
.
If the texture cannot be accommodated, texture state is set to 0.
A one-component texture image uses only the red component of the RGBA
color extracted from
data
.
A two-component image uses the R and A values.
A three-component image uses the R, G, and B values.
A four-component image uses all of the RGBA components.
Depth textures can be treated as LUMINANCE, INTENSITY or ALPHA textures during texture filtering and application. Image-based shadowing can be enabled by comparing texture r coordinates to depth texture values to generate a boolean result. See
glTexParameter
for details on texture comparison.
Notes
Texturing has no effect in color index mode.
If the
ARB_imaging
extension is supported, RGBA elements may
also be processed by the imaging pipeline. The following stages may be
applied to an RGBA color before color component clamping to the range
:
- 1. Color component replacement by the color table specified for
-
GL_COLOR_TABLE , if enabled. See glColorTable .
- 2. Two-dimensional Convolution filtering, if enabled.
-
See glConvolutionFilter1D .
- 3. RGBA components may be multiplied by GL_POST_CONVOLUTION_c_SCALE ,
-
and added to GL_POST_CONVOLUTION_c_BIAS , if enabled. See glPixelTransfer .
- 4. Color component replacement by the color table specified for
-
GL_POST_CONVOLUTION_COLOR_TABLE , if enabled. See glColorTable .
- 5. Transformation by the color matrix.
-
See glMatrixMode .
- 6. RGBA components may be multiplied by GL_POST_COLOR_MATRIX_c_SCALE ,
-
and added to GL_POST_COLOR_MATRIX_c_BIAS , if enabled. See glPixelTransfer .
- 7. Color component replacement by the color table specified for
-
GL_POST_COLOR_MATRIX_COLOR_TABLE , if enabled. See glColorTable .
The texture image can be represented by the same data formats
as the pixels in a
glDrawPixels
command,
except that
GL_STENCIL_INDEX
cannot be used.
glPixelStore
and
glPixelTransfer
modes affect texture images
in exactly the way they affect
glDrawPixels
.
glTexImage2D
and
GL_PROXY_TEXTURE_2D
are available only if the GL
version is 1.1 or greater.
Internal formats other than 1, 2, 3, or 4 may be used only if the GL
version is 1.1 or greater.
In GL version 1.1 or greater,
data
may be a null pointer.
In this case, texture memory is
allocated to accommodate a texture of width
width
and height
height
.
You can then download subtextures to initialize this
texture memory.
The image is undefined if the user tries to apply
an uninitialized portion of the texture image to a primitive.
Formats
GL_BGR
, and
GL_BGRA
and types
GL_UNSIGNED_BYTE_3_3_2
,
GL_UNSIGNED_BYTE_2_3_3_REV
,
GL_UNSIGNED_SHORT_5_6_5
,
GL_UNSIGNED_SHORT_5_6_5_REV
,
GL_UNSIGNED_SHORT_4_4_4_4
,
GL_UNSIGNED_SHORT_4_4_4_4_REV
,
GL_UNSIGNED_SHORT_5_5_5_1
,
GL_UNSIGNED_SHORT_1_5_5_5_REV
,
GL_UNSIGNED_INT_8_8_8_8
,
GL_UNSIGNED_INT_8_8_8_8_REV
,
GL_UNSIGNED_INT_10_10_10_2
, and
GL_UNSIGNED_INT_2_10_10_10_REV
are available only if the GL version
is 1.2 or greater.
When the
ARB_multitexture
extension is supported or the GL version is 1.3 or greater,
glTexImage2D
specifies the two-dimensional texture for the current texture unit,
specified with
glActiveTexture
.
GL_TEXTURE_CUBE_MAP
and
GL_PROXY_TEXTURE_CUBE_MAP
are available only if the GL
version is 1.3 or greater.
GL_DEPTH_COMPONENT
,
GL_DEPTH_COMPONENT16
,
GL_DEPTH_COMPONENT24
, and
GL_DEPTH_COMPONENT32
are available only
if the GL version is 1.4 or greater.
Non-power-of-two textures are supported if the GL version is 2.0 or greater, or if the implementation exports the
GL_ARB_texture_non_power_of_two
extension.
The
GL_SRGB
,
GL_SRGB8
,
GL_SRGB_ALPHA
,
GL_SRGB8_ALPHA8
,
GL_SLUMINANCE
,
GL_SLUMINANCE8
,
GL_SLUMINANCE_ALPHA
, and
GL_SLUMINANCE8_ALPHA8
internal formats are only available if the GL version is 2.1 or greater.
Errors
GL_INVALID_ENUM
is generated if
target
is not
GL_TEXTURE_2D
,
GL_PROXY_TEXTURE_2D
,
GL_PROXY_TEXTURE_CUBE_MAP
,
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
, or
GL_TEXTURE_CUBE_MAP_NEGATIVE_Z
.
GL_INVALID_ENUM
is generated if
target
is one of the six cube map 2D image targets and the width and height parameters are not equal.
GL_INVALID_ENUM
is generated if
type
is not a type constant.
GL_INVALID_VALUE
is generated if
width
or
height
is less than 0
or greater than 2 +
GL_MAX_TEXTURE_SIZE
.
GL_INVALID_VALUE
is generated if
level
is less than 0.
GL_INVALID_VALUE
may be generated if
level
is greater than
,
where
max
is the returned value of
GL_MAX_TEXTURE_SIZE
.
GL_INVALID_VALUE
is generated if
internalFormat
is not 1, 2, 3, 4, or one of the
accepted resolution and format symbolic constants.
GL_INVALID_VALUE
is generated if
width
or
height
is less than 0
or greater than 2 +
GL_MAX_TEXTURE_SIZE
.
GL_INVALID_VALUE
is generated if non-power-of-two textures are not supported and the
width
or
height
cannot be represented as
for some
integer value of
k
.
GL_INVALID_VALUE
is generated if
border
is not 0 or 1.
GL_INVALID_OPERATION
is generated if
type
is one of
GL_UNSIGNED_BYTE_3_3_2
,
GL_UNSIGNED_BYTE_2_3_3_REV
,
GL_UNSIGNED_SHORT_5_6_5
, or
GL_UNSIGNED_SHORT_5_6_5_REV
and
format
is not
GL_RGB
.
GL_INVALID_OPERATION
is generated if
type
is one of
GL_UNSIGNED_SHORT_4_4_4_4
,
GL_UNSIGNED_SHORT_4_4_4_4_REV
,
GL_UNSIGNED_SHORT_5_5_5_1
,
GL_UNSIGNED_SHORT_1_5_5_5_REV
,
GL_UNSIGNED_INT_8_8_8_8
,
GL_UNSIGNED_INT_8_8_8_8_REV
,
GL_UNSIGNED_INT_10_10_10_2
, or
GL_UNSIGNED_INT_2_10_10_10_REV
and
format
is neither
GL_RGBA
nor
GL_BGRA
.
GL_INVALID_OPERATION
is generated if
target
is not
GL_TEXTURE_2D
or
GL_PROXY_TEXTURE_2D
and
internalFormat
is
GL_DEPTH_COMPONENT
,
GL_DEPTH_COMPONENT16
,
GL_DEPTH_COMPONENT24
, or
GL_DEPTH_COMPONENT32
.
GL_INVALID_OPERATION
is generated if
format
is
GL_DEPTH_COMPONENT
and
internalFormat
is not
GL_DEPTH_COMPONENT
,
GL_DEPTH_COMPONENT16
,
GL_DEPTH_COMPONENT24
, or
GL_DEPTH_COMPONENT32
.
GL_INVALID_OPERATION
is generated if
internalFormat
is
GL_DEPTH_COMPONENT
,
GL_DEPTH_COMPONENT16
,
GL_DEPTH_COMPONENT24
, or
GL_DEPTH_COMPONENT32
, and
format
is
not
GL_DEPTH_COMPONENT
.
GL_INVALID_OPERATION
is generated if a non-zero buffer object name is bound to the
GL_PIXEL_UNPACK_BUFFER
target and the buffer object's data store is currently mapped.
GL_INVALID_OPERATION
is generated if a non-zero buffer object name is bound to the
GL_PIXEL_UNPACK_BUFFER
target and the data would be unpacked from the buffer
object such that the memory reads required would exceed the data store size.
GL_INVALID_OPERATION
is generated if a non-zero buffer object name is bound to the
GL_PIXEL_UNPACK_BUFFER
target and
data
is not evenly divisible
into the number of bytes needed to store in memory a datum indicated by
type
.
GL_INVALID_OPERATION
is generated if
glTexImage2D
is executed between the execution of
glBegin
and the corresponding execution of
glEnd
.
Associated Gets
glGet
with argument
GL_PIXEL_UNPACK_BUFFER_BINDING
See Also
glActiveTexture
,
glColorTable
,
glConvolutionFilter2D
,
glCopyPixels
,
glCopyTexImage1D
,
glCopyTexImage2D
,
glCopyTexSubImage1D
,
glCopyTexSubImage2D
,
glCopyTexSubImage3D
,
glDrawPixels
,
glMatrixMode
,
glPixelStore
,
glPixelTransfer
,
glSeparableFilter2D
,
glTexEnv
,
glTexGen
,
glTexImage1D
,
glTexImage3D
,
glTexSubImage1D
,
glTexSubImage2D
,
glTexSubImage3D
,
glTexParameter
Copyright
Copyright
1991-2006
Silicon Graphics, Inc. This document is licensed under the SGI
Free Software B License. For details, see
http://oss.sgi.com/projects/FreeB/
.
Sample Code References
The following code samples have been found which appear to reference the functions described here. Take care that the code may be old, broken or not even use PyOpenGL.
glTexImage2D
{LGPL or GPL or MPL} Kamaelia
Sketches/THF/Packages/Kamaelia/Community/THF/Kamaelia/UI/OpenGL/OpenGLDisplay.py
Lines: 882
{LGPL or GPL or MPL} Kamaelia
Sketches/THF/Packages/Kamaelia/Community/THF/Kamaelia/UI/OpenGL/Label.py
Lines: 207
{LGPL or GPL or MPL} Kamaelia
Sketches/THF/Packages/Kamaelia/Community/THF/Kamaelia/UI/OpenGL/TexPlane.py
Lines: 139
{LGPL or GPL or MPL} Kamaelia
Sketches/THF/Packages/Kamaelia/Community/THF/Kamaelia/UI/OpenGL/Button.py
Lines: 259
{LGPL or GPL or MPL} Kamaelia
Sketches/CL/Topology3D/THF/Kamaelia/UI/OpenGL/OpenGLDisplay.py
Lines: 883
{LGPL or GPL or MPL} Kamaelia
Sketches/CL/Topology3D/THF/Sketches/playground/Display3D.py
Lines: 496