2011-2014
Khronos Group
glTexStorage3D
3G

# glTexStorage3D

simultaneously specify storage for all levels of a three-dimensional or two-dimensional array texture

## C Specification

                    void glTexStorage3D
                    GLenum target
                    GLsizei levels
                    GLenum internalformat
                    GLsizei width
                    GLsizei height
                    GLsizei depth

## Parameters

`target`

  Specify the target of the operation. `target` must be one of `GL_TEXTURE_3D`, or `GL_TEXTURE_2D_ARRAY`.

`levels`

  Specify the number of texture levels.

`internalformat`

  Specifies the sized internal format to be used to store texture image data.

`width`

  Specifies the width of the texture, in texels.

`height`

  Specifies the height of the texture, in texels.

`depth`

  Specifies the depth of the texture, in texels.

## Description

`glTexStorage3D` specifies the storage requirements for all levels of a three-dimensional or two-dimensional array texture simultaneously. Once a texture is specified with this command, the format and dimensions of all levels become immutable. The contents of the image may still be modified, however, its storage requirements may not change. Such a texture is referred to as an immutable-format texture.

The behavior of `glTexStorage3D` depends on the `target` parameter. When `target` is `GL_TEXTURE_3D`, calling `glTexStorage3D` is equivalent, assuming no errors are generated, to executing the following pseudo-code:

        for (i = 0; i < levels; i++)
        {
            glTexImage3D(target, i, internalformat, width, height, depth, 0, format, type, NULL);
            width = max(1, (width / 2));
            height = max(1, (height / 2));
            depth = max(1, (depth / 2));
        }

When `target` is `GL_TEXTURE_2D_ARRAY`, `glTexStorage3D` is equivalent to:

        for (i = 0; i < levels; i++)
        {
            glTexImage3D(target, i, internalformat, width, height, depth, 0, format, type, NULL);
            width = max(1, (width / 2));
            height = max(1, (height / 2));
        }

Since no texture data is actually provided, the values used in the pseudo-code for `format` and `type` are irrelevant and may be considered to be any values that are legal for the chosen `internalformat` enumerant. `internalformat` must be one of the sized internal formats given in Table 1, or one of the compressed internal formats given in Table 2 below. Upon success, the value of `GL_TEXTURE_IMMUTABLE_FORMAT` becomes `GL_TRUE`. The value of `GL_TEXTURE_IMMUTABLE_FORMAT` may be discovered by calling glGetTexParameter with `pname` set to `GL_TEXTURE_IMMUTABLE_FORMAT`. No further changes to the dimensions or format of the texture object may be made. Using any command that might alter the dimensions or format of the texture object (such as glTexImage3D or another call to `glTexStorage3D`) will result in the generation of a `GL_INVALID_OPERATION` error, even if it would not, in fact, alter the dimensions or format of the object.

## Errors

`GL_INVALID_OPERATION` is generated if the default texture object is curently bound to `target`.

`GL_INVALID_OPERATION` is generated if the texture object curently bound to `target` already has `GL_TEXTURE_IMMUTABLE_FORMAT` set to `GL_TRUE`.

`GL_INVALID_ENUM` is generated if `internalformat` is not a valid sized internal format.

`GL_INVALID_ENUM` is generated if `target` is not one of the accepted target enumerants.

`GL_INVALID_VALUE` is generated if `width`, `height`, `depth` or `levels` are less than 1.

`GL_INVALID_OPERATION` is generated if `target` is `GL_TEXTURE_3D` and `levels` is greater than log 2 max width , height , depth + 1 .

`GL_INVALID_OPERATION` is generated if `target` is `GL_TEXTURE_2D_ARRAY` and `levels` is greater than log 2 max width , height + 1 .

## API Version Support

glTexStorage3D

## See Also

glTexImage3D, glCompressedTexImage3D, glTexStorage2D.

## Copyright

Copyright 2011-2014 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.