Generation

generator/accompaniment.py

@@ -7,6 +7,8 @@ import functools
 import generator.model
 import generator.rhythm
 
+ATTACKS_PER_BEAT = {'bass': fractions.Fraction(1, 2), 'upper': fractions.Fraction(3, 4), 'electric': fractions.Fraction(1, 2)}
+
 @dataclasses.dataclass(frozen=True)
 class Context:
   measure: dict
@@ -75,7 +77,7 @@ def measure_rank(bar, offset, intervals, melody_attacks, melody_spans, companion
   missing_bars = int(bool(intervals) and not spans and role != 'electric')
   uncovered = sum(not any(start < b and end > a for start, end in spans) for a, b in intervals)
   duration = sum((b - a for a, b in intervals), fractions.Fraction())
-  density = abs(len(attacks) - duration / {'electric': 2, 'bass': 2, 'upper': 1}[role])
+  density = abs(len(attacks) - duration * ATTACKS_PER_BEAT[role])
   collisions = sum((t in melody_attacks) + (t in companions) for t in attacks)
   occupied = sum(any(a <= t < b for a, b in melody_spans) for t in attacks)
   pulse = -sum(2 if t == 0 else 1 if t.denominator == 1 else 0 for t in attacks)