# `GlyphsCallback interpolateMaster:font:interpolation:error:`

*Instance Method*

## Declaration

```swift
func interpolateMaster(_ master: GSFontMaster, font: GSFont, interpolation: [AnyHashable : Any]) throws
```

```objc
- (BOOL) interpolateMaster:(GSFontMaster *) master font:(GSFont *) font interpolation:(NSDictionary *) interpolation error:(NSError **) error;
```

```python
interpolateMaster_font_interpolation_error_(master: GSFontMaster, font: GSFont, interpolation: dict) -> tuple[bool, NSError]
```