NAME¶

glBindImageTexture - bind a level of a texture to an image unit

C SPECIFICATION¶

PARAMETERS¶

unit texture level layered layer access format

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. Table 1. 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/.