1991-2006
Silicon Graphics, Inc.
glCopyTexSubImage3D
3G

# 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` 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 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

`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.

## 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 operation.

`GL_INVALID_VALUE` is generated if `level` is less than 0.

`GL_INVALID_VALUE` may be generated if level > log 2 &af; max , where max is the returned value of `GL_MAX_3D_TEXTURE_SIZE`.

`GL_INVALID_VALUE` is generated if xoffset < - b , xoffset + width > w - b , yoffset < - b , yoffset + height > h - b , zoffset < - b , or zoffset + 1 > 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, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glPixelStore, glPixelTransfer, glReadBuffer, glTexEnv, glTexGen, glTexImage1D, glTexImage2D, glTexImage3D, glTexParameter, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D

## Copyright

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/.