target
texture
internalformat
buffer
offset
size
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. m[blue]http://opencontent.org/openpub/m[].