# `GSCurvatureSquaredForT`

*Function*

## Declaration

```swift
func GSCurvatureSquaredForT(_ P1: NSPoint, _ P2: NSPoint, _ P3: NSPoint, _ P4: NSPoint, _ t: CGFloat) -> CGFloat
```

```objc
CGFloat GSCurvatureSquaredForT(NSPoint P1, NSPoint P2, NSPoint P3, NSPoint P4, CGFloat t);
```

```python
GSCurvatureSquaredForT(P1: NSPoint, P2: NSPoint, P3: NSPoint, P4: NSPoint, t: float) -> float
```

## See Also

### Inflections, Curvature, and Normals

- [`GSCubicHasInflection`](/Core/GlyphsCore/GSCubicHasInflection)
- [`GSComputeInflection`](/Core/GlyphsCore/GSComputeInflection)
- [`GSComputeInflectionTimes`](/Core/GlyphsCore/GSComputeInflectionTimes)
- [`GSComputeInflectionTimesTolerance`](/Core/GlyphsCore/GSComputeInflectionTimesTolerance)
- [`GSTransformComponents`](/Core/GlyphsCore/GSTransformComponents)
- [`curvatureMaxima`](/Core/GlyphsCore/curvatureMaxima)
- [`GSSignedCurvatureForT`](/Core/GlyphsCore/GSSignedCurvatureForT) — Use this function as compared to `curvatureSquaredForT` if you compute the square root of the result anyway or if you need to know the sign of the curvature.
- [`GSNormalCubicForT`](/Core/GlyphsCore/GSNormalCubicForT)
- [`GSNormalQuadraticForT`](/Core/GlyphsCore/GSNormalQuadraticForT)