Initialize iterator with the current FontStash state. FontStash state can be changed after initialization without affecting the iterator.
Returns font ascender (positive).
Returns font descender (negative).
Returns current text bounds.
Returns current horizontal text bounds.
Returns current vertical text bounds.
Returns font line height.
Put some text into iterator, calculate new values.
(Re)initialize iterator with the current FontStash state. FontStash state can be changed after initialization without affecting the iterator.
This iterator can be used to do text measurement.