## Name

glCopyTexSubImage1D, glCopyTextureSubImage1D — copy a one-dimensional texture subimage

## C Specification

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

`void glCopyTextureSubImage1D(` | GLuint texture,
| GLint level,
| GLint xoffset,
| GLint x,
| GLint y,
| GLsizei width`)`;

## Parameters

`target`

  Specifies the target to which the texture object is bound for `glCopyTexSubImage1D` function. Must be `GL_TEXTURE_1D`.

`texture`

  Specifies the texture object name for `glCopyTextureSubImage1D` 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 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

`glCopyTexSubImage1D` and `glCopyTextureSubImage1D` replace 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). For `glCopyTexSubImage1D`, the texture object that is bound to `target` will be used for the process. For `glCopyTextureSubImage1D`, `texture` tells which texture object should be used for the purpose of the call.

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 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.

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 or width parameters of the specified texture array or to texel values outside the specified subregion.

## Notes

The glPixelStore mode affects texture images.

## Errors

`GL_INVALID_ENUM` is generated by `glCopyTexSubImage1D` if `target` is not `GL_TEXTURE_1D`.

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

`GL_INVALID_OPERATION` is generated by `glCopyTextureSubImage1D` if `texture` is not the name of an existing texture object, or if the effective target of `texture` is not `GL_TEXTURE_1D`.

`GL_INVALID_OPERATION` is generated if the texture array has not been defined by a previous glTexImage1D, glCopyTexImage1D, or glTexStorage1D 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_TEXTURE_SIZE`.

`GL_INVALID_VALUE` is generated if xoffset < 0 , or xoffset + width > w , where w is the `GL_TEXTURE_WIDTH` 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
`glCopyTexSubImage1D` | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔
`glCopyTextureSubImage1D` | - | - | - | - | - | - | - | - | - | - | - | ✔

## See Also

glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage2D, 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/.