glCopyTexSubImage3D — copy a three-dimensional texture subimage
void glCopyTexSubImage3D( | GLenum | target, |
GLint | level, | |
GLint | xoffset, | |
GLint | yoffset, | |
GLint | zoffset, | |
GLint | x, | |
GLint | y, | |
GLsizei | width, | |
GLsizei | height) ; |
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.
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
yoffset
through
zoffset
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
The destination rectangle in the texture array may not include any texels outside the texture array as it was originally specified. It is not an error to specify a subtexture 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 associated 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.
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 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 texture. See glTexImage2D for
specific details.
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 operation.
GL_INVALID_VALUE
is generated if level
is less than 0.
GL_INVALID_VALUE
may be generated if
GL_MAX_3D_TEXTURE_SIZE
.
GL_INVALID_VALUE
is generated if
GL_TEXTURE_WIDTH
,
GL_TEXTURE_HEIGHT
,
GL_TEXTURE_DEPTH
,
and
GL_TEXTURE_BORDER
of the texture image being modified.
Note that
GL_INVALID_OPERATION
is generated if glCopyTexSubImage3D
is executed
between the execution of glBegin and the corresponding
execution of glEnd.
glCopyPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glPixelStore, glPixelTransfer, glReadBuffer, glTexEnv, glTexGen, glTexImage1D, glTexImage2D, glTexImage3D, glTexParameter, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D
Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.