# `GSLayer addExtremePointsForce:checkSelection:`

*Instance Method*

Adds nodes at extrema of path segments.

## Declaration

```swift
func addExtremePointsForce(_ force: Bool, checkSelection: Bool)
```

```objc
- (void) addExtremePointsForce:(BOOL) force checkSelection:(BOOL) checkSelection;
```

```python
addExtremePointsForce_checkSelection_(force: bool, checkSelection: bool)
```

## Parameters

- `force` — Whether to add extrema even when they would make a segment unsuitable.
- `checkSelection` — Whether to process only selected path segments.

## See Also

### Adding Path Nodes

- [`GSLayer addExtremePoints`](/Core/GlyphsCore/GSLayer/addExtremePoints) — Adds nodes at extrema of all path segments where needed.
- [`GSLayer addInflectionPoints`](/Core/GlyphsCore/GSLayer/addInflectionPoints) — Adds nodes at inflection points of cubic segments.