# shz_mat4x4_apply_permutation_wxyz

Source: https://sh4zam.com/api/matrix/shz_mat4x4_apply_permutation_wxyz/

```c
SHZ_INLINE void shz_mat4x4_apply_permutation_wxyz(shz_mat4x4_t* mat) SHZ_NOEXCEPT;
```

Multiplies and accumulates a permutation matrix, which reorders the components of transformed vectors to be in WXYZ order.

## Parameters

| Name | Type | Description |
| --- | --- | --- |
| `mat` | `shz_mat4x4_t *` |  |

## Returns

Nothing (`void`).

## Warnings

- This routine clobbers XMTRX.

## 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/))
- `shz_mat4x4_t` and `shz_mat2x2_t` arguments must be 8-byte aligned. Unaligned data goes through the `float[16]` parameters of the `_unaligned` routines.

## Availability

- **C++ equivalent:** [`shz::mat4x4::apply_permutation_wxyz`](https://sh4zam.com/api/cpp/mat4x4/#apply_permutation_wxyz)
- **Type-generic form:** none
- **Back-ends:** SH4: shared C implementation · SW: portable C · SPU: shared C implementation
- **Defined in:** [`sh4zam/shz_matrix.h:519`](https://github.com/gyrovorbis/sh4zam/blob/ba1e30c88d49df0311870b229e1dd860ef26c477/include/sh4zam/shz_matrix.h#L519)
- **Module:** [Matrix](https://sh4zam.com/api/matrix/), section "Applying"