# drawingArcs

Canonical: https://docs.shumoku.dev/en/library/api/drawingArcs
Language: en

@shumoku/core · 0.4.2 · function

# drawingArcs

[Source](https://github.com/konoe-akitoshi/shumoku/blob/main/libs/@shumoku/core/src/libs/@shumoku/core/src/drawing/arcs.ts#L29)

How each vertex of a polyline is rounded, given the radius asked for at each (0 at the ends). The arc is tangent to both runs, so a vertex turning through θ takes \`r·tan(θ/2)\` off each, at most half of either run; where that does not fit, the radius is reduced to fit. A vertex that is not rounded (an end, no radius, a run of no length, no turn) has no arc. This is the one place a drawn corner is worked out; the renderer writes the arcs out and the layout samples them.

```
drawingArcs(points: readonly Point[], radii: readonly number[]): Arc | undefined[]
```

## Parameters

| Parameter | Type | Description | Default |
| --- | --- | --- | --- |
| `points` | `readonly Point[]` | No additional description. | `—` |
| `radii` | `readonly number[]` | No additional description. | `—` |

## Returns

```
Arc | undefined[]
```

[`libs/@shumoku/core/src/libs/@shumoku/core/src/drawing/arcs.ts:29`](https://github.com/konoe-akitoshi/shumoku/blob/main/libs/@shumoku/core/src/libs/@shumoku/core/src/drawing/arcs.ts#L29)