getStemDirection method
Get stem direction for this voice
Uses forced direction if set, otherwise follows convention:
- Voice 1: up
- Voice 2: down
- Voice 3+: up (or based on position)
Implementation
StemDirection getStemDirection() {
if (forcedStemDirection != null) return forcedStemDirection!;
return number.isEven ? StemDirection.down : StemDirection.up;
}