# `GSLayer bsbAtHeight:`

*Instance Method*

Bottom side bearing measured at an x coordinate.

## Declaration

```swift
func bsb(atHeight height: Int) -> CGFloat
```

```objc
- (CGFloat) bsbAtHeight:(NSInteger) height;
```

```python
bsbAtHeight_(height: int) -> float
```

## Discussion

Returns `NSNotFound` when no outline intersection can be measured at the coordinate.

## See Also

### Vertical Metrics

- [`GSLayer.TSB`](/Core/GlyphsCore/GSLayer/TSB) — Distance from the top metric to the top outline edge.
- [`GSLayer.TSBFast`](/Core/GlyphsCore/GSLayer/TSBFast) — Cached top side bearing without updating metrics.
- [`GSLayer TSBPlain`](/Core/GlyphsCore/GSLayer/TSBPlain) — Top side bearing without normalizing the no-outline value.
- [`GSLayer.BSB`](/Core/GlyphsCore/GSLayer/BSB) — Distance from the bottom outline edge to the vertical advance.
- [`GSLayer.BSBFast`](/Core/GlyphsCore/GSLayer/BSBFast) — Cached bottom side bearing without updating metrics.
- [`GSLayer BSBPlain`](/Core/GlyphsCore/GSLayer/BSBPlain) — Bottom side bearing without normalizing the no-outline value.
- [`GSLayer.vertWidth`](/Core/GlyphsCore/GSLayer/vertWidth) — Advance width for vertical text layout.
- [`GSLayer.vertOrigin`](/Core/GlyphsCore/GSLayer/vertOrigin) — Vertical origin offset for vertical text layout.
- [`GSLayer tsbAtHeight:`](/Core/GlyphsCore/GSLayer/tsbAtHeight:) — Top side bearing measured at an x coordinate.
- [`GSLayer setTsb:atHeight:`](/Core/GlyphsCore/GSLayer/setTsb:atHeight:) — Sets the top side bearing measured at an x coordinate.
- [`GSLayer setBsb:atHeight:`](/Core/GlyphsCore/GSLayer/setBsb:atHeight:) — Sets the bottom side bearing measured at an x coordinate.