glTexImage1D(3G) OpenGL Reference glTexImage1D(3G)
glTexImage1D - specify a one-dimensional texture image
void glTexImage1D( GLenum target,
GLint level,
GLint internalformat,
GLsizei width,
GLint border,
GLenum format,
GLenum type,
const GLvoid *pixels )
target Specifies the target texture. Must be GL_TEXTURE_1D or
GL_PROXY_TEXTURE_1D.
level Specifies the level-of-detail number. Level 0 is the
base image level. Level n is the nth mipmap reduction
image.
internalformat Specifies the number of color components in the texture.
Must be 1, 2, 3, or 4, or one of the following symbolic
constants: GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12,
GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8,
GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA,
GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2,
GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4,
GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16,
GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8,
GL_INTENSITY12, GL_INTENSITY16, GL_RGB, GL_R3_G3_B2,
GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16,
GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8,
GL_RGB10_A2, GL_RGBA12, GL_RGBA16, GL_DUAL_ALPHA4_SGIS,
GL_DUAL_ALPHA8_SGIS, GL_DUAL_ALPHA12_SGIS,
GL_DUAL_ALPHA16_SGIS, GL_DUAL_LUMINANCE4_SGIS,
GL_DUAL_LUMINANCE8_SGIS, GL_DUAL_LUMINANCE12_SGIS,
GL_DUAL_LUMINANCE16_SGIS, GL_DUAL_INTENSITY4_SGIS,
GL_DUAL_INTENSITY8_SGIS, GL_DUAL_INTENSITY12_SGIS,
GL_DUAL_INTENSITY16_SGIS, GL_DUAL_LUMINANCE_ALPHA4_SGIS,
GL_DUAL_LUMINANCE_ALPHA8_SGIS, GL_QUAD_ALPHA4_SGIS,
GL_QUAD_ALPHA8_SGIS, GL_QUAD_LUMINANCE4_SGIS,
GL_QUAD_LUMINANCE8_SGIS, GL_QUAD_INTENSITY4_SGIS, or
GL_QUAD_INTENSITY8_SGIS.
width Specifies the width of the texture image. Must be
n
2 +2(border) for some integer n. All implementations
support texture images that are at least 64 texels wide.
The height of the 1D texture image is 1.
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glTexImage1D(3G) OpenGL Reference glTexImage1D(3G)
border Specifies the width of the border. Must be either 0 or
1.
format Specifies the format of the pixel data. The following
symbolic values are accepted: GL_COLOR_INDEX, GL_RED,
GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA,
GL_BGRA, GL_ABGR_EXT, GL_LUMINANCE, and
GL_LUMINANCE_ALPHA.
type Specifies the data type of the pixel data. The following
symbolic values are accepted: GL_UNSIGNED_BYTE, GL_BYTE,
GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT,
GL_INT, GL_FLOAT, 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.
pixels Specifies a pointer to the image data in memory.
Texturing maps a portion of a specified texture image onto each graphical
primitive for which texturing is enabled. To enable and disable onedimensional
texturing, call glEnable and glDisable with argument
GL_TEXTURE_1D.
Texture images are defined with glTexImage1D. The arguments describe the
parameters of the texture image, such as width, width of the border,
level-of-detail number (see glTexParameter), and the internal resolution
and format used to store the image. 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_1D, no data is read from pixels, 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_1D, data is read from pixels 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).
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glTexImage1D(3G) OpenGL Reference glTexImage1D(3G)
The first element corresponds to the left end of the texture array.
Subsequent elements progress left-to-right through the remaining texels
in the texture array. The final element corresponds to the right end of
the texture array.
format determines the composition of each element in pixels. It can
assume one of eleven symbolic values:
GL_COLOR_INDEX [Toc] [Back]
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_RGB [Toc] [Back]
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
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glTexImage1D(3G) OpenGL Reference glTexImage1D(3G)
clamped to the range [0,1] (see glPixelTransfer).
GL_RGBA [Toc] [Back]
GL_BGRA [Toc] [Back]
GL_ABGR_EXT [Toc] [Back]
Each element contains all four components. 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 [Toc] [Back]
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 [Toc] [Back]
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).
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 preceding
representations.)
Use the GL_PROXY_TEXTURE_1D 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 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 from pixels. 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.
The mapping of components from the canonical RGBA to the internal storage
formats that begin with GL_DUAL_ and GL_QUAD_ needs to be clarified.
There are three cases. The first case is for the GL_DUAL_ formats that
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glTexImage1D(3G) OpenGL Reference glTexImage1D(3G)
are groups of GL_ALPHA, GL_LUMINANCE, and GL_INTENSITY. The R value goes
to the first group while the A value goes to the second group. The
second case is for the GL_DUAL_ formats that are groups of
GL_LUMINANCE_ALPHA. The R and G values go to the first group while the B
and A values go to the second group. The third case is for the GL_QUAD_
formats. The R value goes to the first group, the G value to the second
group, the B value to the third group, and the A value to the fourth
group.
Normally glTexImage1D is synchronous: OpenGL executes a glTexImage1D
command in the order it is issued in the OpenGL command stream. Calling
glEnable with parameter GL_ASYNC_TEX_IMAGE_SGIX causes subsequent
glTexImage1D commands to be asynchronous as defined by the SGIX_async
extension. An asynchronous glTexImage1D command samples the OpenGL state
vector at the point in the OpenGL command stream where the command is
issued, but the results of the command (e.g. availability of texels for
use in rasterization) do not happen until some unspecified time in the
future. In particular, the order of the asynchronous command relative to
other OpenGL commands issued later in the command stream is undefined.
An implementation may choose to execute asynchronous commands in parallel
with the normal command stream or at some convenient time in the future.
Calling glDisable with parameter GL_ASYNC_TEX_IMAGE_SGIX restores the
default synchronous behavior for subsequent glTexImage1D commands. It
does not affect any pending asynchronous glTexImage commands, or wait for
their completion.
When an asynchronous glTexImage1D command is issued, it is associated
with the current value of GL_ASYNC_MARKER_SGIX as defined by the
SGIX_async extension. A program can determine if an asynchronous
glTexImage1D command has completed by using the glFinishAsyncSGIX or
glPollAsyncSGIX commands.
There is a maximum number of asynchronous glTexImage commands that can be
outstanding at any one time, defined by the implementation. This value
can be queried with glGetIntegerv with argument
GL_MAX_ASYNC_TEX_IMAGE_SGIX.
Texturing has no effect in color index mode.
If the GL_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 [0, 1]:
1. Color component replacement by the color table specified for
GL_COLOR_TABLE, if enabled. See glColorTable.
2. One-dimensional convolution filtering, if enabled. See
glConvolutionFilter1D.
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glTexImage1D(3G) OpenGL Reference glTexImage1D(3G)
If a convolution filter changes the __width of the texture (by
processing with a GL_CONVOLUTION_BORDER_MODE of GL_REDUCE, for
n
example), the width must 2 +2(border), for some integer n, after
filtering.
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 and
GL_DEPTH_COMPONENT cannot be used. glPixelStore and glPixelTransfer
modes affect texture images in exactly the way they affect glDrawPixels.
GL_ABGR_EXT is part of the EXT_abgr extension, not part of the core GL
command set. If GL_EXT_abgr is included in the string returned by
glGetString, when called with argument GL_EXTENSIONS, extension EXT_abgr
is supported by the connection.
GL_PROXY_TEXTURE_1D may be used 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, pixels may be a null pointer. In this case
texture memory is allocated to accommodate a texture of width width. You
can then download subtextures to initialize the texture memory. The image
is undefined if the program 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.
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glTexImage1D(3G) OpenGL Reference glTexImage1D(3G)
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_1D or
GL_PROXY_TEXTURE_1D.
GL_INVALID_ENUM is generated if format is not an accepted format
constant. Format constants other than GL_STENCIL_INDEX and
GL_DEPTH_COMPONENT are accepted.
GL_INVALID_ENUM is generated if type is not a type constant.
GL_INVALID_ENUM is generated if type is GL_BITMAP and format is not
GL_COLOR_INDEX.
GL_INVALID_VALUE is generated if level is less than 0.
GL_INVALID_VALUE may be generated if level is greater than log max, where
2
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 is less than 0 or greater than 2 +
n
GL_MAX_TEXTURE_SIZE, or if it cannot be represented as 2 + 2(border) for
some integer value of n.
GL_INVALID_VALUE is generated if border is not 0 or 1.
GL_INVALID_OPERATION is generated if glTexImage1D is executed between the
execution of glBegin and the corresponding execution of glEnd.
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 not GL_RGBA, GL_BGRA or GL_ABGR_EXT.
GL_INVALID_OPERATION is generated if GL_ASYNC_TEX_IMAGE_SGIX is enabled
and the number of asynchronous glTexImage commands that have been issued
but not queried (using glFinishAsyncSGIX or glPollAsyncSGIX) exceeds
GL_MAX_ASYNC_TEX_IMAGE_SGIX.
glGetTexImage
glIsEnabled with argument GL_TEXTURE_1D
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glTexImage1D(3G) OpenGL Reference glTexImage1D(3G)
MACHINE DEPENDENCIES
The SGIX_async and SGIX_async_pixel extensions are implemented only on
Octane2 VPro systems.
RealityEngine, RealityEngine2, and VTX systems do not support color
matrix transformations on images as they are loaded to or read back from
texture memory.
RealityEngine, RealityEngine2, and VTX systems do not support convolving
images as they are loaded into texture memory.
RealityEngine, RealityEngine2, and VTX systems do not support histogram
or minmax operations on images as they are being loaded into texture
memory.
The EXT_packed_pixels extension is not supported on RealityEngine,
RealityEngine2, and VTX systems.
On RealityEngine, RealityEngine2, and VTX systems:
1. The texture environment must be defined and texturing must be
enabled before loading a texture.
2. Texture formats composed only of alpha are not supported.
3. Borders are not supported; hence the border width must be 0.
4. Proxy textures are not supported.
5. glTexImage2D with a NULL texture image may not be used inside a
display list.
6. GL_INTERLACE_SGIX is not supported (see glEnable).
On High Impact and Maximum Impact systems the number of bits per
component, represented internally, is the same for all components and
will be 4, 8, or 12 bits per component. All specified internal formats
will receive an equal or greater representation in this scheme, up to the
12-bit limit. High Impact and Maximum Impact on Indigo2 systems do not
support texture internal formats of the type GL_INTENSITY or GL_ALPHA,
although High Impact and Maximum Impact on Octane systems do support
these types.
High Impact and Maximum Impact on Indigo2 systems without the TRAM option
card support 4 bits per component for GL_RGB and GL_RGBA, 4/8 bits per
component for GL_LUMINANCE_ALPHA, and 4/8/12 bits per component for
GL_LUMINANCE.
Texture borders are not supported on InfiniteReality systems, so the
border width should always be zero. Applications should use the texture
wrap mode GL_CLAMP_TO_EDGE_SGIS to obtain behavior similar to that of
borders.
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glTexImage1D(3G) OpenGL Reference glTexImage1D(3G)
The SGIS_texture_select extension is supported only on InfiniteReality
systems, High Impact and Maximum Impact on Octane systems, and High
Impact and Maximum Impact on Indigo2 systems with the TRAM option card.
On InfiniteReality, RealityEngine, RealityEngine2, and VTX systems, High
Impact and Maximum Impact systems, and Octane2 VPro systems, texture
objects (see glBindTextureEXT) are significantly faster than displaylisted
textures, and therefore are recommended for managing texture
memory.
glColorTable, glConvolutionFilter1D, glCopyPixels, glCopyTexImage1D,
glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D,
glCopyTexSubImage3D, glDrawPixels, glMatrixMode, glPixelStore,
glPixelTransfer, glTexEnv, glTexGen, glTexImage2D, glTexImage3D,
glTexSubImage1D, glTexSubImage2D, glTexSubImage3D, glTexParameter,
glAsyncMarkerSGIX, glDeleteAsyncMarkersSGIX, glFinishAsyncSGIX,
glGenAsyncMarkersSGIX, glIsAsyncMarkerSGIX, glPollAsyncSGIX
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