glTextureView — initialize a texture as a data alias of another texture's data store
void glTextureView( | GLuint texture, |
| GLenum target, | |
| GLuint origtexture, | |
| GLenum internalformat, | |
| GLuint minlevel, | |
| GLuint numlevels, | |
| GLuint minlayer, | |
GLuint numlayers); |
textureSpecifies the texture object to be initialized as a view.
targetSpecifies the target to be used for the newly initialized texture.
origtextureSpecifies the name of a texture object of which to make a view.
internalFormatSpecifies the internal format for the newly created view.
minlevelSpecifies lowest level of detail of the view.
numlevelsSpecifies the number of levels of detail to include in the view.
minlayerSpecifies the index of the first layer to include in the view.
numlayersSpecifies the number of layers to include in the view.
glTextureView initializes a texture object as an
alias, or view of another texture object, sharing some or all of the
parent texture's data store with the initialized texture. texture
specifies a name previously reserved by a successful call to glGenTextures
but that has not yet been bound or given a target. target
specifies the target for the newly initialized texture and must be compatible
with the target of the parent texture, given in origtexture
as specified in the following table:
| Original Target | Compatible New Targets |
|---|---|
GL_TEXTURE_1D | GL_TEXTURE_1D, GL_TEXTURE_1D_ARRAY |
GL_TEXTURE_2D | GL_TEXTURE_2D, GL_TEXTURE_2D_ARRAY |
GL_TEXTURE_3D | GL_TEXTURE_3D |
GL_TEXTURE_CUBE_MAP | GL_TEXTURE_CUBE_MAP, GL_TEXTURE_2D, GL_TEXTURE_2D_ARRAY, GL_TEXTUER_CUBE_MAP_ARRAY |
GL_TEXTURE_RECTANGLE | GL_TEXTURE_RECTANGLE |
GL_TEXTURE_BUFFER | none |
GL_TEXTURE_1D_ARRAY | GL_TEXTURE_1D, GL_TEXTURE_1D_ARRAY |
GL_TEXTURE_2D_ARRAY | GL_TEXTURE_2D, GL_TEXTURE_2D_ARRAY |
GL_TEXTURE_CUBE_MAP_ARRAY | GL_TEXTURE_CUBE_MAP, GL_TEXTURE_2D, GL_TEXTURE_2D_ARRAY, GL_TEXTUER_CUBE_MAP_ARRAY |
GL_TEXTURE_2D_MULTISAMPLE | GL_TEXTURE_2D_MULTISAMPLE, GL_TEXTURE_MULTISAMPLE_ARRAY |
GL_TEXTURE_2D_MULTISAMPLE_ARRAY | GL_TEXTURE_2D_MULTISAMPLE, GL_TEXTURE_MULTISAMPLE_ARRAY |
The value of GL_TEXTURE_IMMUTABLE_FORMAT for origtexture
must be GL_TRUE.
After initialization, texture inherits the data store of
the parent texture, origtexture and is usable as a normal
texture object with target target. Data in the shared store
is reinterpreted with the new internal format specified by internalformat.
internalformat must be compatible with the internal format
of the parent texture as specified in the following table:
| Class | Internal Formats |
|---|---|
| 128-bit | GL_RGBA32F, GL_RGBA32UI, GL_RGBA32I |
| 96-bit | GL_RGB32F, GL_RGB32UI, GL_RGB32I |
| 64-bit | GL_RGBA16F, GL_RG32F, GL_RGBA16UI,
GL_RG32UI, GL_RGBA16I, GL_RG32I, GL_RGBA16, GL_RGBA16_SNORM |
| 48-bit | GL_RGB16, GL_RGB16_SNORM, GL_RGB16F, GL_RGB16UI, GL_RGB16I |
| 32-bit | GL_RG16F, GL_R11F_G11F_B10F, GL_R32F, GL_RGB10_A2UI,
GL_RGBA8UI, GL_RG16UI, GL_R32UI, GL_RGBA8I,
GL_RG16I, GL_R32I, GL_RGB10_A2, GL_RGBA8,
GL_RG16, GL_RGBA8_SNORM, GL_RG16_SNORM, GL_SRGB8_ALPHA8,
GL_RGB9_E5 |
| 24-bit | GL_RGB8, GL_RGB8_SNORM, GL_SRGB8,
GL_RGB8UI, GL_RGB8I |
| 16-bit | GL_R16F, GL_RG8UI, GL_R16UI, GL_RG8I,
GL_R16I, GL_RG8, GL_R16, GL_RG8_SNORM, GL_R16_SNORM |
| 8-bit | GL_R8UI, GL_R8I, GL_R8, GL_R8_SNORM |
GL_RGTC1_RED | GL_COMPRESSED_RED_RGTC1, GL_COMPRESSED_SIGNED_RED_RGTC1 |
GL_RGTC2_RG | GL_COMPRESSED_RG_RGTC2, GL_COMPRESSED_SIGNED_RG_RGTC2 |
GL_BPTC_UNORM | GL_COMPRESSED_RGBA_BPTC_UNORM, GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM |
GL_BPTC_FLOAT | GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT, GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT |
If the original texture is an array or has multiple mipmap levels,
the parameters minlayer, numlayers, minlevel, and numlevels
control which of those slices and levels are considered part of the texture.
The minlevel and minlayer parameters are relative to the view of the
original texture. If numlayers or numlevels extend beyond the original
texture, they are clamped to the max extent of the original texture.
If the new texture's target is GL_TEXTURE_CUBE_MAP, the clamped numlayers
must be equal to 6. If the new texture's target is GL_TEXTURE_CUBE_MAP_ARRAY,
then numlayers counts layer-faces rather than layers, and the clamped
numlayers must be a multiple of 6. If the new texture's target is GL_TEXTURE_CUBE_MAP or
GL_TEXTURE_CUBE_MAP_ARRAY, the width and height of the original texture's
levels must be equal.
When the original texture's target is GL_TEXTURE_CUBE_MAP, the layer
parameters are interpreted in the same order as if it were a
GL_TEXTURE_CUBE_MAP_ARRAY with 6 layer-faces.
If target is GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, GL_TEXTURE_RECTANGLE, or
GL_TEXTURE_2D_MULTISAMPLE, numlayers must equal 1.
The dimensions of the original texture must be less than or equal to the maximum
supported dimensions of the new target. For example, if the original texture has a GL_TEXTURE_2D_ARRAY
target and its width is greater than GL_MAX_CUBE_MAP_TEXTURE_SIZE, an error
will be generated if glTextureView is called to create a GL_TEXTURE_CUBE_MAP
view.
Texture commands that take a level or layer parameter, such as
glTexSubImage2D, interpret that parameter to be relative to the view of the
texture. i.e. the mipmap level of the data store that would be updated via
TexSubImage2D would be the sum of level and the value of
GL_TEXTURE_VIEW_MIN_LEVEL.
GL_INVALID_VALUE is generated if minlayer or minlevel
are larger than the greatest layer or level of origtexture.
GL_INVALID_OPERATION is generated if target is not compatible
with the target of origtexture.
GL_INVALID_OPERATION is generated if the dimensions of origtexture
are greater than the maximum supported dimensions for target.
GL_INVALID_OPERATION is generated if internalformat is not compatible
with the internal format of origtexture.
GL_INVALID_OPERATION is generated if texture has already been bound
or otherwise given a target.
GL_INVALID_OPERATION is generated if the value of GL_TEXTURE_IMMUTABLE_FORMAT
for origtexture is not GL_TRUE.
GL_INVALID_OPERATION is generated if origtexture is not the name of an
existing texture object.
GL_INVALID_VALUE is generaged if target is GL_TEXTURE_CUBE_MAP
and numlayers is not 6, or if target is GL_TEXTURE_CUBE_MAP_ARRAY
and numlayers is not an integer multiple of 6.
GL_INVALID_VALUE is generated if target is GL_TEXTURE_1D,
GL_TEXTURE_2D, GL_TEXTURE_3D, GL_TEXTURE_RECTANGLE, or
GL_TEXTURE_2D_MULTISAMPLE and numlayers does not equal 1.
GL_INVALID_VALUE is generated if texture zero or is not the name of a texture previously
returned from a successful call to glGenTextures.
glTexParameter with arguments GL_TEXTURE_VIEW_MIN_LEVEL,
GL_TEXTURE_VIEW_NUM_LEVELS, GL_TEXTURE_VIEW_MIN_LAYER,
GL_TEXTURE_VIEW_NUM_LAYERS, or GL_TEXTURE_IMMUTABLE_LEVELS.
Copyright © 2012 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/.