GLCOPYTEXSUBIMAGE1DMachTen Programmer’s ManuGLCOPYTEXSUBIMAGE1D()

NAME
glCopyTexSubImage1D - copy a one-dimensional texture
subimage

C SPECIFICATION
void glCopyTexSubImage1D( GLenum target,
GLint level,
GLint xoffset,
GLint x,
GLint y,
GLsizei width )

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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 the texel offset within the texture
array.

x, y Specify the window coordinates of the left corner
of the row of pixels to be copied.

width Specifies the width of the texture subimage.

DESCRIPTION
glCopyTexSubImage1D replaces a portion of a one-
dimensional texture image with pixels from the current
GL_READ_BUFFER (rather than from main memory, as is the
case for glTexSubImage1D).

The screen-aligned pixel row with left corner at (x, y),
and with length width replaces the portion of the texture
array with x indices xoffset through $"xoffset" ~+~
"width" ~-~ 1$, inclusive. The destination in the texture
array may not include any texels outside the texture array
as it was originally specified.

The pixels in the row are processed exactly as if glCopyP-
ixels had been called, but the process stops just before
final conversion. At this point all pixel component val-
ues are clamped to the range [0, 1] and then converted to
the texture’s internal format for storage in the texel
array.

It is not an error to specify a subtexture with zero
width, but such a specification has no effect. If any of
the pixels within the specified row of the current
GL_READ_BUFFER are outside the read window associated with
the current rendering context, then the values obtained
for those pixels are undefined.

No change is made to the internalformat, width, or border
parameters of the specified texture array or to texel
values outside the specified subregion.

NOTES
glCopyTexSubImage1D 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
GL_TEXTURE_1D.

GL_INVALID_OPERATION is generated if the texture array has
not been defined by a previous glTexImage1D or glCopyTex-
Image1D operation.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level$>log sub 2$
max, where max is the returned value of
GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if y$ ~<~ ~-b$ or if width$
~<~ ~-b$, where $b$ is the border width of the texture
array.

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

ASSOCIATED GETS
glGetTexImage
glIsEnabled with argument GL_TEXTURE_1D

SEE ALSO
glCopyPixels, glCopyTexImage1D, glCopyTexImage2D, glCopy-
TexSubImage2D, glPixelStore, glPixelTransfer, glTexEnv,
glTexGen, glTexImage1D, glTexImage2D, glTexParameter,
glTexSubImage1D, glTexSubImage2D

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