diff options
Diffstat (limited to 'musiclib.nim')
| -rw-r--r-- | musiclib.nim | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/musiclib.nim b/musiclib.nim index 4984596..91e63c4 100644 --- a/musiclib.nim +++ b/musiclib.nim @@ -16,12 +16,9 @@ type vol: float osc: OscFn -## give some seconds for the note to fade out -const HACK_DROPOFF_DELAY = 2.0 - const HACK_LONGEST_NOTE = 16.0 -func process*(music: var seq[ProcessedNote], notes: openArray[Note]; start_init: float, speed: float=1, gain:float = 1) = +func process*(music: var seq[ProcessedNote], notes: openArray[Note]; start_init: float, speed: float=1) = ## Adds a list of notes to the music list ## ## `notes` sequence of notes with no rests in between @@ -32,7 +29,7 @@ func process*(music: var seq[ProcessedNote], notes: openArray[Note]; start_init: assert note.len <= HACK_LONGEST_NOTE, &"note too long: {note.len}" start = t let stop = t + note.len / speed - music &= (start, stop, note.freq, note.vol * gain, note.osc) + music &= (start, stop, note.freq, note.vol, note.osc) t = stop func sortByStart*(music: var seq[ProcessedNote]) = @@ -45,7 +42,7 @@ func bisect(music: openArray[ProcessedNote], x: float): int = music.lowerBound(x, (m, key) => cmp(m.start, key)) -const GAIN_BIAS: float = pow(2.0, 28.0) +const GAIN_BIAS: float = pow(2.0, 31.0) proc at*(music: openArray[ProcessedNote], t: float): int32 = ## Returns the total intensity of music sampled at time t @@ -59,10 +56,13 @@ proc at*(music: openArray[ProcessedNote], t: float): int32 = while i >= 0: let m = music[i] assert m.start <= t - if m.stop + HACK_DROPOFF_DELAY >= t: - ret += m.vol * m.osc(m.freq, t - m.start) - if m.start + HACK_LONGEST_NOTE + HACK_DROPOFF_DELAY < t: + if m.start + HACK_LONGEST_NOTE < t: break + else: + ret += m.vol * m.osc(m.freq, t - m.start) i -= 1 - int32(ret * GAIN_BIAS) + ret *= GAIN_BIAS + + # clip sample + clamp(ret, int32.low.float..int32.high.float).int32 |