glCopyTexSubImage1D(3G)	       OpenGL Reference	       glCopyTexSubImage1D(3G)

NAME    [Toc]    [Back]

     glCopyTexSubImage1D - copy	a one-dimensional texture subimage

C SPECIFICATION    [Toc]    [Back]

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

PARAMETERS    [Toc]    [Back]

     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    [Toc]    [Back]

     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 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 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.



									Page 1






glCopyTexSubImage1D(3G)	       OpenGL Reference	       glCopyTexSubImage1D(3G)

NOTES    [Toc]    [Back]

     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.

     When the GL_ARB_imaging extension is supported, the RGBA components
     copied from the framebuffer may be	processed by the imaging pipeline.
     See glTexImage1D for specific details.

ERRORS    [Toc]    [Back]

     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 glCopyTexImage1D operation.

     GL_INVALID_VALUE is generated if level is less than 0.

     GL_INVALID_VALUE may be generated if level>log  max, where	max is the
						   2
     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    [Toc]    [Back]

     glGetTexImage
     glIsEnabled with argument GL_TEXTURE_1D


MACHINE	DEPENDENCIES
     glCopyTexSubImage1D and glCopyTexSubImage1DEXT are	not supported on
     RealityEngine, RealityEngine2, and	VTX systems.

     On	InfiniteReality	systems, there is a performance	benefit	when the width
     of	the image to be	transferred to texture memory is a multiple of 8.

     Texture borders are not supported on InfiniteReality systems.
     Applications should use borderless	textures and GL_CLAMP_TO_EDGE_SGIS
     wrap mode.

     On	High Impact and	Maximum	Impact systems,	if the right side of the image
     to	be transferred to texture memory is not	the right side of the texture,
     then its index must be a multiple of 32, where index = xoffset+width.
     Otherwise it will generate	a GL_INVALID_VALUE error.



									Page 2






glCopyTexSubImage1D(3G)	       OpenGL Reference	       glCopyTexSubImage1D(3G)

SEE ALSO    [Toc]    [Back]

     glCopyPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage2D,
     glCopyTexSubImage3D, glPixelStore,	glPixelTransfer, glReadBuffer,
     glTexEnv, glTexGen, glTexImage1D, glTexImage2D, glTexImage3D,
     glTexParameter, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D


									PPPPaaaaggggeeee 3333