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