glBindImageTexture — bind a level of a texture to an image unit
void glBindImageTexture( | GLuint unit, |
| GLuint texture, | |
| GLint level, | |
| GLboolean layered, | |
| GLint layer, | |
| GLenum access, | |
GLenum format); |
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 loads and stores.
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 two-dimensional array texture, a cube map 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 loads and 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.
| Image Unit Format | Format Qualifier |
|---|---|
GL_RGBA32F | rgba32f |
GL_RGBA16F | rgba16f |
GL_R32F | r32f |
GL_RGBA32UI | rgba32ui |
GL_RGBA16UI | rgba16ui |
GL_RGBA8UI | rgba8ui |
GL_R32UI | r32ui |
GL_RGBA32I | rgba32i |
GL_RGBA16I | rgba16i |
GL_RGBA8I | rgba8i |
GL_R32I | r32i |
GL_RGBA8 | rgba8 |
GL_RGBA8_SNORM | rgba8_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 ES 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.
The glBindImageTexture can only be used with immutable textures. This is intended to guide developers towards immutable textures.
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_OPERATION is generated if texture is the name of an immutable 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.
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.
| OpenGL ES API Version | |||
|---|---|---|---|
| Function Name | 2.0 | 3.0 | 3.1 |
glBindImageTexture | - | - | ✔ |
glGenTextures, glTexStorage2D, glTexStorage3D, glBindTexture
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. https://opencontent.org/openpub/.