GLTEXIMAGE1D(3G) UNIX Programmer's Manual GLTEXIMAGE1D(3G)
NAME
glTexImage1D - specify a one-dimensional texture image
C SPECIFICATION
void glTexImage1D( GLenum target,
GLint level,
GLint internalFormat,
GLsizei width,
GLint border,
GLenum format,
GLenum type,
const GLvoid *pixels )
PARAMETERS
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, or GL_RGBA16.
width Specifies the width of the texture image.
Must be 2n+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.
border Specifies the width of the border. Must be
either 0 or 1.
format Specifies the of the pixel data. The fol-
lowing symbolic values are accepted:
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GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE,
GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA,
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.
DESCRIPTION
Texturing maps a portion of a specified texture image onto
each graphical primitive for which texturing is enabled. To
enable and disable one-dimensional 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 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 pix-
els, 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
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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 deter-
mined by GL_UNPACK_LSB_FIRST (see glPixelStore).
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
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 result-
ing index is converted to a set of color com-
ponents 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 mul-
tiplied 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 mul-
tiplied 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
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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
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 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
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 mul-
tiplied 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).
If an application wants to store the texture at a certain
resolution or in a certain , it can request the resolution
and with internalFormat. The GL will choose an internal
representation that closely approximates that requested by
internalFormat, but it may not match exactly. (The represen-
tations specified by GL_LUMINANCE, GL_LUMINANCE_ALPHA,
GL_RGB, and GL_RGBA must match exactly. The numeric values
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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 update and recompute its best match for the requested
storage resolution and . To query this state, call
glGetTexLevelParameter. If the texture cannot be accommo-
dated, 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 com-
ponents.
NOTES
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 follow-
ing stages may be applied to an RGBA color before color com-
ponent 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.
If a convolution filter changes the __width of the tex-
ture (by processing with a GL_CONVOLUTION_BORDER_MODE of
GL_REDUCE, for example), the width must 2n+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
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glColorTable.
The texture image can be represented by the same data for-
mats 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_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 tex-
ture 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 GL_ARB_multitexture extension is supported,
glTexImage1D specifies the one-dimensional texture for the
current texture unit, specified with glActiveTextureARB.
ERRORS
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
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
log2max, where max is the returned value of
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GL_MAX_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if internalFormat is not 1, 2,
3, 4, or one of the accepted resolution and symbolic con-
stants.
GL_INVALID_VALUE is generated if width is less than 0 or
greater than 2 + GL_MAX_TEXTURE_SIZE, or if it cannot be
represented as 2n + 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 exe-
cuted 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 neither GL_RGBA
nor GL_BGRA.
ASSOCIATED GETS
glGetTexImage
glIsEnabled with argument GL_TEXTURE_1D
SEE ALSO
glActiveTextureARB(3G), glColorTable(3G),
glConvolutionFilter1D(3G), glCopyPixels(3G),
glCopyTexImage1D(3G), glCopyTexImage2D(3G),
glCopyTexSubImage1D(3G), glCopyTexSubImage2D(3G),
glCopyTexSubImage3D(3G), glDrawPixels(3G), glMatrixMode(3G),
glPixelStore(3G), glPixelTransfer(3G), glTexEnv(3G),
glTexGen(3G), glTexImage2D(3G), glTexImage3D(3G),
glTexSubImage1D(3G), glTexSubImage2D(3G),
glTexSubImage3D(3G), glTexParameter(3G)
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