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 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: ComponentSized Internal FormatBase TypeComponentsNorm 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.
glTexBufferRange: man4/glTexBufferRange.xml
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 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.