bitfieldExtract - OpenGL 4 Reference Pages

## Name

bitfieldExtract — extract a range of bits from an integer

## Declaration

`genIType bitfieldExtract(` | genIType value,
| int offset,
| int bits`)`;

`genUType bitfieldExtract(` | genUType value,
| int offset,
| int bits`)`;

## Parameters

`value`

  Specifies the integer from which to extract bits.

`offset`

  Specifies the index of the first bit to extract.

`bits`

  Specifies the number of bits to extract.

## Description

`bitfieldExtract` extracts a subset of the bits of `value` and returns it in the least significant bits of the result. The range of bits extracted is [`offset`, `offset` + `bits` - 1].

For unsigned data types, the most significant bits of the result will be set to zero. For signed data types, the most significant bits will be set to the value of bit `offset` + `base` - 1 (i.e., it is sign extended to the width of the return type).

If `bits` is zero, the result will be zero. The result will be undefined if `offset` or `bits` is negative, or if the sum of `offset` and `bits` is greater than the number of bits used to store the operand.

## Version Support

| OpenGL Shading Language Version
--- | ---
Function Name | 1.10 | 1.20 | 1.30 | 1.40 | 1.50 | 3.30 | 4.00 | 4.10 | 4.20 | 4.30 | 4.40 | 4.50
bitfieldInsert | - | - | - | - | - | - | ✔ | ✔ | ✔ | ✔ | ✔ | ✔

## See Also

bitfieldExtract

## Copyright

Copyright © 2011-2014 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/.