glCopyTexSubImage3D(3G)	       OpenGL Reference	       glCopyTexSubImage3D(3G)

NAME    [Toc]    [Back]

     glCopyTexSubImage3D - copy	a three-dimensional texture subimage

C SPECIFICATION    [Toc]    [Back]

     void glCopyTexSubImage3D( GLenum target,
			       GLint level,
			       GLint xoffset,
			       GLint yoffset,
			       GLint zoffset,
			       GLint x,
			       GLint y,
			       GLsizei width,
			       GLsizei height )

PARAMETERS    [Toc]    [Back]

     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    [Toc]    [Back]

     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 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



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glCopyTexSubImage3D(3G)	       OpenGL Reference	       glCopyTexSubImage3D(3G)



     then converted to the texture's internal format 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 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.

NOTES    [Toc]    [Back]

     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 texture.  See glTexImage2D for specific
     details.

ERRORS    [Toc]    [Back]

     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	log max, where
								   2
     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.

     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.




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glCopyTexSubImage3D(3G)	       OpenGL Reference	       glCopyTexSubImage3D(3G)



     GL_INVALID_OPERATION is generated if glCopyTexSubImage3D is executed
     between the execution of glBegin and the corresponding execution of
     glEnd.

ASSOCIATED GETS    [Toc]    [Back]

     glGetTexImage
     glIsEnabled with argument GL_TEXTURE_3D

SEE ALSO    [Toc]    [Back]

     glCopyPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D,
     glCopyTexSubImage2D, glPixelStore,	glPixelTransfer, glReadBuffer,
     glTexEnv, glTexGen, glTexImage1D, glTexImage2D, glTexImage3D,
     glTexParameter, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D


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