GLAPI/glTexBufferRange

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glTexBufferRange
Core in version 4.4
Core since version 4.3
Core ARB extension ARB_texture_buffer_range

glTexBufferRange: bind a range of a buffer's data store to a buffer texture

Function Definition

 void glTexBufferRange(GLenum target​, GLenum internalFormat​, GLuint buffer​, GLintptr offset​, GLsizeiptr size​);
target
Specifies the target of the operation and must be GL_TEXTURE_BUFFER​.
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.

Description

glTexBufferRange attaches the a range of the data store of the buffer object named buffer​ to the active buffer texture, and specifies the internal format for the texel array found in the attached buffer object. 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. target​ must be GL_TEXTURE_BUFFER​. The start of the range is specified by offset​ and the size of the range is specified by size​, 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​ 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:

Internal Format Base Type Count Norm Components
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​ ubyte 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 buffer object is attached to a buffer texture, the given 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 \tfrac{size}{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 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.

Errors

GL_INVALID_ENUM​ is generated if target​ is not GL_TEXTURE_BUFFER​.

GL_INVALID_VALUE​ is generated if offset​ is less than zero.

GL_INVALID_VALUE​ is generated if size​ is less than or equal to zero.

GL_INVALID_VALUE​ is generated 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​.

Associated Gets

glGet with argument GL_TEXTURE_BUFFER_OFFSET_ALIGNMENT​

glGetTexLevelParameter with arguments GL_TEXTURE_BUFFER_OFFSET​ or GL_TEXTURE_BUFFER_SIZE​.

See Also

glActiveTexture, glBindTexture, glGenBuffers, glBufferData, glTexBuffer

Copyright

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/.