glTexBufferRange, glTextureBufferRange — attach a range of a buffer object's data store to a buffer texture object
void glTexBufferRange(
|
GLenum target, |
GLenum internalformat, | |
GLuint buffer, | |
GLintptr offset, | |
GLsizeiptr size) ; |
void glTextureBufferRange(
|
GLuint texture, |
GLenum internalformat, | |
GLuint buffer, | |
GLintptr offset, | |
GLsizei size) ; |
target
Specifies the target to which the texture object is
bound for glTexBufferRange
. Must be
GL_TEXTURE_BUFFER
.
texture
Specifies the texture object name for
glTextureBufferRange
.
internalformat
Specifies the internal format of the data in the store
belonging to buffer
.
buffer
Specifies the name of the buffer object whose storage to attach to the active buffer texture.
offset
Specifies the offset of the start of the range of the buffer's data store to attach.
size
Specifies the size of the range of the buffer's data store to attach.
glTexBufferRange
and
glTextureBufferRange
attach a range of the
data store of a specified buffer object to a specified texture
object, and specify the storage format for the texture image
found in the buffer object. The texture object must be a
buffer texture.
If buffer
is zero, any buffer object
attached to the buffer texture is detached and no new buffer
object is attached. If buffer
is
non-zero, it must be the name of an existing buffer object.
The start and size of the range are specified by
offset
and size
respectively, both measured in basic machine units.
offset
must be greater than or equal to
zero, size
must be greater than zero, and
the sum of offset
and
size
must not exceed the value of
GL_BUFFER_SIZE
for
buffer
. Furthermore,
offset
must be an integer multiple of the
value of
GL_TEXTURE_BUFFER_OFFSET_ALIGNMENT
.
internalformat
specifies the storage
format, and must be one of the following sized internal formats:
Component | |||||||
---|---|---|---|---|---|---|---|
Sized Internal Format | Base Type | Components | Norm | 0 | 1 | 2 | 3 |
GL_R8
|
ubyte | 1 | YES | R | 0 | 0 | 1 |
GL_R16
|
ushort | 1 | YES | R | 0 | 0 | 1 |
GL_R16F
|
half | 1 | NO | R | 0 | 0 | 1 |
GL_R32F
|
float | 1 | NO | R | 0 | 0 | 1 |
GL_R8I
|
byte | 1 | NO | R | 0 | 0 | 1 |
GL_R16I
|
short | 1 | NO | R | 0 | 0 | 1 |
GL_R32I
|
int | 1 | NO | R | 0 | 0 | 1 |
GL_R8UI
|
ubyte | 1 | NO | R | 0 | 0 | 1 |
GL_R16UI
|
ushort | 1 | NO | R | 0 | 0 | 1 |
GL_R32UI
|
uint | 1 | NO | R | 0 | 0 | 1 |
GL_RG8
|
ubyte | 2 | YES | R | G | 0 | 1 |
GL_RG16
|
ushort | 2 | YES | R | G | 0 | 1 |
GL_RG16F
|
half | 2 | NO | R | G | 0 | 1 |
GL_RG32F
|
float | 2 | NO | R | G | 0 | 1 |
GL_RG8I
|
byte | 2 | NO | R | G | 0 | 1 |
GL_RG16I
|
short | 2 | NO | R | G | 0 | 1 |
GL_RG32I
|
int | 2 | NO | R | G | 0 | 1 |
GL_RG8UI
|
ubyte | 2 | NO | R | G | 0 | 1 |
GL_RG16UI
|
ushort | 2 | NO | R | G | 0 | 1 |
GL_RG32UI
|
uint | 2 | NO | R | G | 0 | 1 |
GL_RGB32F
|
float | 3 | NO | R | G | B | 1 |
GL_RGB32I
|
int | 3 | NO | R | G | B | 1 |
GL_RGB32UI
|
uint | 3 | NO | R | G | B | 1 |
GL_RGBA8
|
uint | 4 | YES | R | G | B | A |
GL_RGBA16
|
short | 4 | YES | R | G | B | A |
GL_RGBA16F
|
half | 4 | NO | R | G | B | A |
GL_RGBA32F
|
float | 4 | NO | R | G | B | A |
GL_RGBA8I
|
byte | 4 | NO | R | G | B | A |
GL_RGBA16I
|
short | 4 | NO | R | G | B | A |
GL_RGBA32I
|
int | 4 | NO | R | G | B | A |
GL_RGBA8UI
|
ubyte | 4 | NO | R | G | B | A |
GL_RGBA16UI
|
ushort | 4 | NO | R | G | B | A |
GL_RGBA32UI
|
uint | 4 | NO | R | G | B | A |
When a range of a buffer object is attached to a buffer texture,
the specified range of the buffer object's data store is taken
as the texture's texel array. The number of texels in the buffer
texture's texel array is given by
$$ \left\lfloor { size \over { components \times sizeof(base\_type) } } \right\rfloor $$
where $components$ and $base\_type$ are the element count and
base data type for elements, as specified in the table above.
The number of texels in the texel array is then clamped to the
value of the implementation-dependent limit
GL_MAX_TEXTURE_BUFFER_SIZE
. When a buffer
texture is accessed in a shader, the results of a texel fetch
are undefined if the specified texel coordinate is negative, or
greater than or equal to the clamped number of texels in the
texel array.
GL_INVALID_ENUM
is generated by
glTexBufferRange
if
target
is not
GL_TEXTURE_BUFFER
.
GL_INVALID_OPERATION
is generated by
glTextureBufferRange
if
texture
is not the name of an existing
texture object.
GL_INVALID_ENUM
is generated by
glTextureBufferRange
if the effective
target of texture
is not
GL_TEXTURE_BUFFER
.
GL_INVALID_ENUM
is generated if
internalformat
is not one of the sized
internal formats described above.
GL_INVALID_OPERATION
is generated if
buffer
is not zero and is not the name of
an existing buffer object.
GL_INVALID_VALUE
is generated if
offset
is negative, if
size
is less than or equal to zero, or if
offset
+ size
is
greater than the value of GL_BUFFER_SIZE
for buffer
.
GL_INVALID_VALUE
is generated if
offset
is not an integer multiple of the
value of
GL_TEXTURE_BUFFER_OFFSET_ALIGNMENT
.
glGet
with argument
GL_TEXTURE_BUFFER_OFFSET_ALIGNMENT
glGetTexLevelParameter
with arguments GL_TEXTURE_BUFFER_OFFSET
or
GL_TEXTURE_BUFFER_SIZE
.
OpenGL Version | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Function / Feature Name | 2.0 | 2.1 | 3.0 | 3.1 | 3.2 | 3.3 | 4.0 | 4.1 | 4.2 | 4.3 | 4.4 | 4.5 |
glTexBufferRange
|
- | - | - | - | - | - | - | - | - | ✔ | ✔ | ✔ |
glTextureBufferRange
|
- | - | - | - | - | - | - | - | - | - | - | ✔ |
Copyright © 2012-2014 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. http://opencontent.org/openpub/.