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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 )
eqn not supported
- 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 $2 sup n + 2 ( "border" )$ 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 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_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 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 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).
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 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
- 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 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).
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 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 update and recompute its best match for the requested
storage resolution and . 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.
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.
- If a convolution filter changes the __width of the texture (by
- processing
with a GL_CONVOLUTION_BORDER_MODE of GL_REDUCE, for example), the width
must $2 sup n + 2 ( "border" )$, 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_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.
When the GL_ARB_multitexture extension is supported,
glTexImage1D specifies the one-dimensional texture for the current texture
unit, specified with glActiveTextureARB.
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 $log sub 2$max, 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 symbolic constants.
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 $2 sup n ~+~ 2("border")$
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 neither GL_RGBA nor GL_BGRA.
glGetTexImage
glIsEnabled with argument GL_TEXTURE_1D
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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