## Name

glCopyTexSubImage2D, glCopyTextureSubImage2D — copy a two-dimensional texture subimage

## C Specification

`void glCopyTexSubImage2D(` | GLenum target,
| GLint level,
| GLint xoffset,
| GLint yoffset,
| GLint x,
| GLint y,
| GLsizei width,
| GLsizei height`)`;

`void glCopyTextureSubImage2D(` | GLuint texture,
| GLint level,
| GLint xoffset,
| GLint yoffset,
| GLint x,
| GLint y,
| GLsizei width,
| GLsizei height`)`;

## Parameters

`target`

  Specifies the target to which the texture object is bound for `glCopyTexSubImage2D` function. Must be `GL_TEXTURE_1D_ARRAY`, `GL_TEXTURE_2D`, `GL_TEXTURE_CUBE_MAP_POSITIVE_X`, `GL_TEXTURE_CUBE_MAP_NEGATIVE_X`, `GL_TEXTURE_CUBE_MAP_POSITIVE_Y`, `GL_TEXTURE_CUBE_MAP_NEGATIVE_Y`, `GL_TEXTURE_CUBE_MAP_POSITIVE_Z`, `GL_TEXTURE_CUBE_MAP_NEGATIVE_Z`, or `GL_TEXTURE_RECTANGLE`.

`texture`

  Specifies the texture object name for `glCopyTextureSubImage2D` function.

`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.

`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

`glCopyTexSubImage2D` and `glCopyTextureSubImage2D` replace a rectangular portion of a two-dimensional texture image, cube-map texture image, rectangular image, or a linear portion of a number of slices of a one-dimensional array texture with pixels from the current `GL_READ_BUFFER` (rather than from main memory, as is the case for glTexSubImage2D).

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 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.

When `target` is `GL_TEXTURE_1D_ARRAY` then the y coordinate and height are treated as the start slice and number of slices to modify.

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, or height, 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_2D`, `GL_TEXTURE_CUBE_MAP_POSITIVE_X`, `GL_TEXTURE_CUBE_MAP_NEGATIVE_X`, `GL_TEXTURE_CUBE_MAP_POSITIVE_Y`, `GL_TEXTURE_CUBE_MAP_NEGATIVE_Y`, `GL_TEXTURE_CUBE_MAP_POSITIVE_Z`, `GL_TEXTURE_CUBE_MAP_NEGATIVE_Z`, `GL_TEXTURE_1D_ARRAY`, or `GL_RECTANGLE`.

`GL_INVALID_FRAMEBUFFER_OPERATION` is generated if the object bound to `GL_READ_FRAMEBUFFER_BINDING` is not framebuffer complete.

`GL_INVALID_OPERATION` is generated if the texture array has not been defined by a previous glTexImage2D, glTexStorage2D or glCopyTexImage2D operation.

`GL_INVALID_OPERATION` is generated by `glCopyTextureSubImage2D` if `texture` is not the name of an existing texture object.

`GL_INVALID_OPERATION` is generated by `glCopyTextureSubImage2D` if the effective target of texture does not correspond to one of the texture targets supported by the function.

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

`GL_INVALID_VALUE` is generated if the effective target is `GL_TEXTURE_RECTANGLE` and `level` is not zero.

`GL_INVALID_VALUE` may be generated if level > log 2 ⁡ max , where max is the returned value of `GL_MAX_TEXTURE_SIZE`.

`GL_INVALID_VALUE` is generated if xoffset < 0 , xoffset + width > w , yoffset < 0 , or yoffset + height > 0 ,, where w is the `GL_TEXTURE_WIDTH`, h is the `GL_TEXTURE_HEIGHT` and of the texture image being modified.

`GL_INVALID_OPERATION` is generated if:

- the read buffer is `GL_NONE`, or

- the value of `GL_READ_FRAMEBUFFER_BINDING` is non-zero, and:

  - the read buffer selects an attachment that has no image attached, or

  - the effective value of `GL_SAMPLE_BUFFERS` for the read framebuffer is one.

## Associated Gets

glGetTexImage

## Version Support

| OpenGL Version
--- | ---
Function / Feature Name | 2.0 | 2.1 | 3.0 | 3.1 | 3.2 | 3.3 | 4.0 | 4.1 | 4.2 | 4.3 | 4.4 | 4.5
`glCopyTexSubImage2D` | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔
`glCopyTextureSubImage2D` | - | - | - | - | - | - | - | - | - | - | - | ✔

## See Also

glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage3D, glPixelStore, glReadBuffer, glTexImage1D, glTexImage2D, glTexImage3D, glTexParameter, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D

## Copyright

Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2012-2014 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.