A bitmask that determines to which bits that stencil operations can write.
- iOS 8.0+
- macOS 10.11+
- tvOS 9.0+
write are used for logical AND operations to values that are going to be written into a stencil attachment as the result of a stencil operation.
The least significant bits of the write mask are used. The default value is all ones. A logical AND operation with the default
write does not change the value.