Function squareRotate

squareRotate(
    dx: number,
    dy: number,
    rotationIndex: number,
    rotations: number,
): { dx: number; dy: number }
TerrainRotate for a square or isometric grid: exact 90-degree steps only (rotations must be a multiple of 4, or 0).
Parameters
- dx: number
- dy: number
- rotationIndex: number
- rotations: number
Returns { dx: number; dy: number }
Example
```
import { squareRotate } from '@datamoc/mw_games/two-d/render';

console.log(squareRotate(1, 0, 1, 4)); // { dx: 0, dy: 1 } - one 90-degree step
```
- Defined in src/two-d/render/TerrainGraphics.ts:83