2013 Khronos Group
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` or `GL_TEXTURE_2D_ARRAY`.

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 or two-dimensional array 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 glReadPixels 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

glPixelStore modes affect texture images.

## 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 ⁡ max , where max is the returned value of `GL_MAX_3D_TEXTURE_SIZE` if target is `GL_TEXTURE_3D` or the returned value of `GL_MAX_ARRAY_TEXTURE_LAYERS` if target is `GL_TEXTURE_2D_ARRAY`.

`GL_INVALID_VALUE` is generated if xoffset < 0 , xoffset + width > w , yoffset < 0 , yoffset + height > h , zoffset < 0 , or zoffset + 1 > d , where w is the `GL_TEXTURE_WIDTH`, h is the `GL_TEXTURE_HEIGHT`, d is the `GL_TEXTURE_DEPTH` and of the texture image being modified. Note that w, h, and d include twice the border width.

## Associated Gets

glGetTexImage

## See Also

glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glPixelStore, glReadBuffer, glTexImage1D, glTexImage2D, glTexImage3D, glTexParameter, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D

## Copyright

Copyright 1991-2006 Silicon Graphics, Inc. Copyright 2012-2013 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.