2010 Khronos Group>
glBindImageTexture 3G
glBindImageTexture bind a level of a texture to an image unit

## C Specification

void `glBindImageTexture` GLuint unit GLuint texture GLint level GLboolean layered GLint layer GLenum access GLenum format

## Parameters

unit

  Specifies the index of the image unit to which to bind the texture

texture

  Specifies the name of the texture to bind to the image unit.

level

  Specifies the level of the texture that is to be bound.

layered

  Specifies whether a layered texture binding is to be established.

layer

  If layered is `GL_FALSE`, specifies the layer of texture to be bound to the image unit. Ignored otherwise.

access

  Specifies a token indicating the type of access that will be performed on the image.

format

  Specifies the format that the elements of the image will be treated as for the purposes of formatted stores.

## Description

`glBindImageTexture` binds a single level of a texture to an image unit for the purpose of reading and writing it from shaders. unit specifies the zero-based index of the image unit to which to bind the texture level. texture specifies the name of an existing texture object to bind to the image unit. If texture is zero, then any existing binding to the image unit is broken. level specifies the level of the texture to bind to the image unit.

If texture is the name of a one-, two-, or three-dimensional array texture, a cube map or cube map array texture, or a two-dimensional multisample array texture, then it is possible to bind either the entire array, or only a single layer of the array to the image unit. In such cases, if layered is `GL_TRUE`, the entire array is attached to the image unit and layer is ignored. However, if layered is `GL_FALSE` then layer specifies the layer of the array to attach to the image unit.

access specifies the access types to be performed by shaders and may be set to `GL_READ_ONLY`, `GL_WRITE_ONLY`, or `GL_READ_WRITE` to indicate read-only, write-only or read-write access, respectively. Violation of the access type specified in access (for example, if a shader writes to an image bound with access set to `GL_READ_ONLY`) will lead to undefined results, possibly including program termination.

format specifies the format that is to be used when performing formatted stores into the image from shaders. format must be compatible with the texture's internal format and must be one of the formats listed in the following table.

Internal Image Formats

Image Unit Format | Format Qualifier
--- | ---
`GL_RGBA32F` | `rgba32f`
`GL_RGBA16F` | `rgba16f`
`GL_RG32F` | `rg32f`
`GL_RG16F` | `rg16f`
`GL_R11F_G11F_B10F` | `r11f_g11f_b10f`
`GL_R32F` | `r32f`
`GL_R16F` | `r16f`
`GL_RGBA32UI` | `rgba32ui`
`GL_RGBA16UI` | `rgba16ui`
`GL_RGB10_A2UI` | `rgb10_a2ui`
`GL_RGBA8UI` | `rgba8ui`
`GL_RG32UI` | `rg32ui`
`GL_RG16UI` | `rg16ui`
`GL_RG8UI` | `rg8ui`
`GL_R32UI` | `r32ui`
`GL_R16UI` | `r16ui`
`GL_R8UI` | `r8ui`
`GL_RGBA32I` | `rgba32i`
`GL_RGBA16I` | `rgba16i`
`GL_RGBA8I` | `rgba8i`
`GL_RG32I` | `rg32i`
`GL_RG16I` | `rg16i`
`GL_RG8I` | `rg8i`
`GL_R32I` | `r32i`
`GL_R16I` | `r16i`
`GL_R8I` | `r8i`
`GL_RGBA16` | `rgba16`
`GL_RGB10_A2` | `rgb10_a2`
`GL_RGBA8` | `rgba8`
`GL_RG16` | `rg16`
`GL_RG8` | `rg8`
`GL_R16` | `r16`
`GL_R8` | `r8`
`GL_RGBA16_SNORM` | `rgba16_snorm`
`GL_RGBA8_SNORM` | `rgba8_snorm`
`GL_RG16_SNORM` | `rg16_snorm`
`GL_RG8_SNORM` | `rg8_snorm`
`GL_R16_SNORM` | `r16_snorm`
`GL_R8_SNORM` | `r8_snorm`

When a texture is bound to an image unit, the format parameter for the image unit need not exactly match the texture internal format as long as the formats are considered compatible as defined in the OpenGL Specification. The matching criterion used for a given texture may be determined by calling glGetTexParameter with value set to `GL_IMAGE_FORMAT_COMPATIBILITY_TYPE`, with return values of `GL_IMAGE_FORMAT_COMPATIBILITY_BY_SIZE` and `GL_IMAGE_FORMAT_COMPATIBILITY_BY_CLASS`, specifying matches by size and class, respectively.

## Notes

The `glBindImageTexture` is available only if the GL version is 4.2 or greater.

## Errors

`GL_INVALID_VALUE` is generated if unit greater than or equal to the value of `GL_MAX_IMAGE_UNITS`.

`GL_INVALID_VALUE` is generated if texture is not the name of an existing texture object.

`GL_INVALID_VALUE` is generated if level or layer is less than zero.

`GL_INVALID_ENUM` is generated if access or format is not one of the supported tokens.

## Associated Gets

glGet with argument `GL_IMAGE_BINDING_NAME`.

glGet with argument `GL_IMAGE_BINDING_LEVEL`.

glGet with argument `GL_IMAGE_BINDING_LAYERED`.

glGet with argument `GL_IMAGE_BINDING_LAYER`.

glGet with argument `GL_IMAGE_BINDING_ACCESS`.

glGet with argument `GL_IMAGE_BINDING_FORMAT`.

## See Also

glGenTextures, glTexImage1D, glTexImage2D, glTexImage3D, glTexStorage1D, glTexStorage2D, glTexStorage3D, glBindTexture

## Copyright

Copyright 2011 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/.