GLCOPYTEXSUBIMAGE3D(3UNIX Programmer's ManGLCOPYTEXSUBIMAGE3D(3G)
NAME
glCopyTexSubImage3D - copy a three-dimensional texture
subimage
C SPECIFICATION
void glCopyTexSubImage3D( GLenum target,
GLint level,
GLint xoffset,
GLint yoffset,
GLint zoffset,
GLint x,
GLint y,
GLsizei width,
GLsizei height )
PARAMETERS
target Specifies the target texture. Must be GL_TEXTURE_3D
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.
yoffset Specifies a texel offset in the y direction within
the texture array.
zoffset Specifies a texel offset in the z direction within
the texture array.
x, y Specify the window coordinates of the lower left
corner of the rectangular region of pixels to be
copied.
width Specifies the width of the texture subimage.
height Specifies the height of the texture subimage.
DESCRIPTION
glCopyTexSubImage3D replaces a rectangular portion of a
three-dimensional texture image with pixels from the current
GL_READ_BUFFER (rather than from main memory, as is the case
for glTexSubImage3D).
The screen-aligned pixel rectangle with lower left corner at
(x, y) and with width width and height height replaces the
portion of the texture array with x indices xoffset through
xoffset + width - 1, inclusive, and y indices yoffset
through yoffset + height - 1, inclusive, at z index zoffset
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GLCOPYTEXSUBIMAGE3D(3UNIX Programmer's ManGLCOPYTEXSUBIMAGE3D(3G)
and at the mipmap level specified by level.
The pixels in the rectangle are processed exactly as if
glCopyPixels had been called, but the process stops just
before final conversion. At this point, all pixel component
values are clamped to the range [0, 1] and then converted to
the texture's internal for storage in the texel array.
The destination rectangle in the texture array may not
include any texels outside the texture array as it was ori-
ginally specified. It is not an error to specify a subtex-
ture with zero width or height, but such a specification has
no effect.
If any of the pixels within the specified rectangle of the
current GL_READ_BUFFER are outside the read window associ-
ated with the current rendering context, then the values
obtained for those pixels are undefined.
No change is made to the internalformat, width, height,
depth, or border parameters of the specified texture array
or to texel values outside the specified subregion.
NOTES
glCopyTexSubImage3D is available only if the GL version is
1.2 or greater.
Texturing has no effect in color index mode.
glPixelStore and glPixelTransfer modes affect texture images
in exactly the way they affect glDrawPixels.
When the GL_ARB_imaging extension is supported, the RGBA
components copied from the framebuffer may be processed by
the imaging pipeline, as if they were a two-dimensional tex-
ture. See glTexImage2D for specific details.
ERRORS
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_3D.
GL_INVALID_OPERATION is generated if the texture array has
not been defined by a previous glTexImage3D or
glCopyTexImage3D operation.
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
GL_MAX_3D_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if x < -b or if y < -b,
where b is the border width of the texture array.
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GLCOPYTEXSUBIMAGE3D(3UNIX Programmer's ManGLCOPYTEXSUBIMAGE3D(3G)
GL_INVALID_VALUE is generated if xoffset < -b,
(xoffset + width) > (w - b), yoffset < -b,
(yoffset + height) > (h - b), zoffset < -b, or
zoffset > (d - b), where w is the GL_TEXTURE_WIDTH, h is the
GL_TEXTURE_HEIGHT, d is the GL_TEXTURE_DEPTH, and b is the
GL_TEXTURE_BORDER of the texture image being modified. Note
that w, h, and d include twice the border width.
GL_INVALID_OPERATION is generated if glCopyTexSubImage3D is
executed between the execution of glBegin and the
corresponding execution of glEnd.
ASSOCIATED GETS
glGetTexImage
glIsEnabled with argument GL_TEXTURE_3D
SEE ALSO
glCopyPixels(3G), glCopyTexImage1D(3G),
glCopyTexImage2D(3G), glCopyTexSubImage1D(3G),
glCopyTexSubImage2D(3G), glPixelStore(3G),
glPixelTransfer(3G), glReadBuffer(3G), glTexEnv(3G),
glTexGen(3G), glTexImage1D(3G), glTexImage2D(3G),
glTexImage3D(3G), glTexParameter(3G), glTexSubImage1D(3G),
glTexSubImage2D(3G), glTexSubImage3D(3G)
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