GLTEXSUBIMAGE1D() MachTen Programmer’s Manual GLTEXSUBIMAGE1D()

NAME
glTexSubImage1D - specify a two-dimensional texture subim-
age

C SPECIFICATION
void glTexSubImage1D( GLenum target,
GLint level,
GLint xoffset,
GLsizei width,
GLenum format,
GLenum type,
const GLvoid *pixels )

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PARAMETERS
target Specifies the target texture. Must be
GL_TEXTURE_1D.

level Specifies the level-of-detail number. Level 0 is
the base image level. Level n is the nth mipmap
reduction image.

xoffset Specifies a texel offset in the x direction
within the texture array.

width Specifies the width of the texture subimage.

format Specifies the format of the pixel data. The fol-
lowing symbolic values are accepted:
GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE,
GL_ALPHA, GL_RGB, GL_RGBA, 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, and GL_FLOAT.

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 or disable one-dimensional texturing, call glEn-
able and glDisable with argument GL_TEXTURE_1D.

glTexSubImage1D redefines a contiguous subregion of an
existing one-dimensional texture image. The texels refer-
enced by pixels replace the portion of the existing tex-
ture array with x indices xoffset and $"xoff-
set"~+~"width"~-~1$, 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 specifi-
cation has no effect.

NOTES
glTexSubImage1D is available only if the GL version is 1.1
or greater.

Texturing has no effect in color index mode.

glPixelStore and glPixelTransfer modes affect texture
images in exactly the way they affect glDrawPixels.

ERRORS
GL_INVALID_ENUM is generated if target is not one of the
allowable values.

GL_INVALID_OPERATION is generated if the texture array has
not been defined by a previous glTexImage1D operation.

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 $"xoffset" ~<~ ~-b$, or
if $("xoffset"~+~"width") ~>~ (w ~-~ b)$. Where $w$ is
the GL_TEXTURE_WIDTH, and $b$ is the width of the
GL_TEXTURE_BORDER of the texture image being modified.
Note that $w$ includes twice the border width.

GL_INVALID_VALUE is generated if width is less than 0.

GL_INVALID_ENUM is generated if format is not an accepted
format constant.

GL_INVALID_ENUM is generated if type is not a type con-
stant.

GL_INVALID_ENUM is generated if type is GL_BITMAP and for-
mat is not GL_COLOR_INDEX.

GL_INVALID_OPERATION is generated if glTexSubImage1D is
executed between the execution of glBegin and the corre-
sponding execution of glEnd.

ASSOCIATED GETS
glGetTexImage
glIsEnabled with argument GL_TEXTURE_1D

SEE ALSO
glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D,
glCopyTexSubImage2D, glDrawPixels, glPixelStore, glPixel-
Transfer, glTexEnv, glTexGen, glTexImage1D, glTexImage2D,
glTexParameter, glTexSubImage2D

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