# shz_xmtrx_init_permutation_yzwx

Source: https://sh4zam.com/api/xmtrx/shz_xmtrx_init_permutation_yzwx/

```c
SHZ_INLINE void shz_xmtrx_init_permutation_yzwx(void) SHZ_NOEXCEPT;
```

Initializes XMTRX to a permutation matrix, which reorders the components of transformed vectors to be in YZWX order.

## Parameters

| Name | Type | Description |
| --- | --- | --- |
| `` | `void` |  |

## Returns

Nothing (`void`).

## Naming and requirements

- `_wxyz`: Register/column permutation so that `FTRV` yields W first (cycle 4 instead of 7), which helps perspective division. ([Naming and Suffixes](https://sh4zam.com/concepts/naming-and-suffixes/))

## Availability

- **C++ equivalent:** [`shz::xmtrx::init_permutation_yzwx`](https://sh4zam.com/api/cpp/xmtrx/#init_permutation_yzwx)
- **Type-generic form:** none
- **Back-ends:** SH4: dedicated SH4 implementation · SW: portable C · SPU: shared C implementation
- **Defined in:** [`sh4zam/shz_xmtrx.h:350`](https://github.com/gyrovorbis/sh4zam/blob/ba1e30c88d49df0311870b229e1dd860ef26c477/include/sh4zam/shz_xmtrx.h#L350)
- **Module:** [XMTRX](https://sh4zam.com/api/xmtrx/), section "Initialization"