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<STRONG>NAME</STRONG>
<STRONG>glTexSubImage1D</STRONG> - specify a two-dimensional texture subimage
<STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG>
void <STRONG>glTexSubImage1D</STRONG>( GLenum <EM>target</EM>,
GLint <EM>level</EM>,
GLint <EM>xoffset</EM>,
GLsizei <EM>width</EM>,
GLenum <EM>format</EM>,
GLenum <EM>type</EM>,
const GLvoid *<EM>pixels</EM> )
<STRONG>PARAMETERS</STRONG>
<EM>target</EM> Specifies the target texture. Must be
<STRONG>GL_TEXTURE_1D</STRONG>.
<EM>level</EM> Specifies the level-of-detail number. Level 0 is
the base image level. Level <EM>n</EM> is the <EM>n</EM>th mipmap
reduction image.
<EM>xoffset</EM> Specifies a texel offset in the x direction within
the texture array.
<EM>width</EM> Specifies the width of the texture subimage.
<EM>format</EM> Specifies the format of the pixel data. The
following symbolic values are accepted:
<STRONG>GL_COLOR_INDEX</STRONG>, <STRONG>GL_RED</STRONG>, <STRONG>GL_GREEN</STRONG>, <STRONG>GL_BLUE</STRONG>,
<STRONG>GL_ALPHA</STRONG>, <STRONG>GL_RGB</STRONG>, <STRONG>GL_RGBA</STRONG>, <STRONG>GL_LUMINANCE</STRONG>, and
<STRONG>GL_LUMINANCE_ALPHA</STRONG>.
<EM>type</EM> Specifies the data type of the pixel data. The
following symbolic values are accepted:
<STRONG>GL_UNSIGNED_BYTE</STRONG>, <STRONG>GL_BYTE</STRONG>, <STRONG>GL_BITMAP</STRONG>,
<STRONG>GL_UNSIGNED_SHORT</STRONG>, <STRONG>GL_SHORT</STRONG>, <STRONG>GL_UNSIGNED_INT</STRONG>,
<STRONG>GL_INT</STRONG>, and <STRONG>GL_FLOAT</STRONG>.
<EM>pixels</EM> Specifies a pointer to the image data in memory.
<STRONG>DESCRIPTION</STRONG>
Texturing maps a portion of a specified texture image onto
each graphical primitive for which texturing is enabled. To
enable or disable one-dimensional texturing, call <STRONG>glEnable</STRONG>
and <STRONG>glDisable</STRONG> with argument <STRONG>GL_TEXTURE_1D</STRONG>.
<STRONG>glTexSubImage1D</STRONG> redefines a contiguous subregion of an
existing one-dimensional texture image. The texels
referenced by <EM>pixels</EM> replace the portion of the existing
texture array with x indices <EM>xoffset</EM> and
xoffset + width - 1, inclusive. This region may not include
any texels outside the range of the texture array as it was
originally specified. It is not an error to specify a
subtexture with width of 0, but such a specification has no
effect.
<STRONG>NOTES</STRONG>
<STRONG>glTexSubImage1D</STRONG> is available only if the GL version is 1.1
or greater.
Texturing has no effect in color index mode.
<STRONG>glPixelStore</STRONG> and <STRONG>glPixelTransfer</STRONG> modes affect texture images
in exactly the way they affect <STRONG>glDrawPixels</STRONG>.
<STRONG>ERRORS</STRONG>
<STRONG>GL_INVALID_ENUM</STRONG> is generated if <EM>target</EM> is not one of the
allowable values.
<STRONG>GL_INVALID_OPERATION</STRONG> is generated if the texture array has
not been defined by a previous <STRONG>glTexImage1D</STRONG> operation.
<STRONG>GL_INVALID_VALUE</STRONG> is generated if <EM>level</EM> is less than 0.
<STRONG>GL_INVALID_VALUE</STRONG> may be generated if <EM>level</EM> is greater than
log <EM>max</EM>, where <EM>max</EM> is the returned value of
<STRONG>GL_MAX_TEXTURE_SIZE</STRONG>.
<STRONG>GL_INVALID_VALUE</STRONG> is generated if xoffset < -b, or if
(xoffset + width) > (w - b). Where w is the
<STRONG>GL_TEXTURE_WIDTH</STRONG>, and b is the width of the
<STRONG>GL_TEXTURE_BORDER</STRONG> of the texture image being modified. Note
that w includes twice the border width.
<STRONG>GL_INVALID_VALUE</STRONG> is generated if <EM>width</EM> is less than 0.
<STRONG>GL_INVALID_ENUM</STRONG> is generated if <EM>format</EM> is not an accepted
format constant.
<STRONG>GL_INVALID_ENUM</STRONG> is generated if <EM>type</EM> is not a type constant.
<STRONG>GL_INVALID_ENUM</STRONG> is generated if <EM>type</EM> is <STRONG>GL_BITMAP</STRONG> and <EM>format</EM>
is not <STRONG>GL_COLOR_INDEX</STRONG>.
<STRONG>GL_INVALID_OPERATION</STRONG> is generated if <STRONG>glTexSubImage1D</STRONG> is
executed between the execution of <STRONG>glBegin</STRONG> and the
corresponding execution of <STRONG>glEnd</STRONG>.
<STRONG>ASSOCIATED</STRONG> <STRONG>GETS</STRONG>
<STRONG>glGetTexImage</STRONG>
<STRONG>glIsEnabled</STRONG> with argument <STRONG>GL_TEXTURE_1D</STRONG>
<STRONG>SEE</STRONG> <STRONG>ALSO</STRONG>
<STRONG>glCopyTexImage1D</STRONG>, <STRONG>glCopyTexImage2D</STRONG>, <STRONG>glCopyTexSubImage1D</STRONG>,
<STRONG>glCopyTexSubImage2D</STRONG>, <STRONG>glDrawPixels</STRONG>, <STRONG>glPixelStore</STRONG>,
<STRONG>glPixelTransfer</STRONG>, <STRONG>glTexEnv</STRONG>, <STRONG>glTexGen</STRONG>, <STRONG>glTexImage1D</STRONG>,
<STRONG>glTexImage2D</STRONG>, <STRONG>glTexParameter</STRONG>, <STRONG>glTexSubImage2D</STRONG>
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