From 9d37e057d75ff9f782b87fbcaf9e82f1ae8b492f Mon Sep 17 00:00:00 2001
From: HiveBeats <38073817+HiveBeats@users.noreply.github.com>
Date: Tue, 1 Nov 2022 09:20:22 +0400
Subject: [PATCH] feat: multiosc oscillator

---
 SoundGen/Oscillator.fs | 25 +++++++++++++++++++++++--
 SoundGen/Program.fs    |  6 +++---
 SoundGen/Synth.fs      | 20 +++++++++++++-------
 3 files changed, 39 insertions(+), 12 deletions(-)

diff --git a/SoundGen/Oscillator.fs b/SoundGen/Oscillator.fs
index d3c0659..e53ad61 100644
--- a/SoundGen/Oscillator.fs
+++ b/SoundGen/Oscillator.fs
@@ -3,6 +3,21 @@ module SoundGen.Oscillator
 open System
 open Settings
 
+type OscillatorType =
+    | Sine
+    | Triangle
+    | Saw
+    | Square
+
+type Hertz = float
+type OscillatorParameter = { Osc: OscillatorType; Freq: Hertz }
+
+type GenerationParameter =
+    { Oscillators: OscillatorParameter list
+      Sample: float }
+
+
+
 let pos hz x = (hz * x / sampleRate) % 1.
 
 let sineosc hz x =
@@ -15,5 +30,11 @@ let squareosc hz x =
 let triangleosc (hz: float) (x: float) = 1. - Math.Abs((pos hz x) - 0.5) * 4.
 let sawosc hz x = (pos hz x) * 2. - 1.
 
-let sinesquareosc hz x =
-    sawosc (hz / 4.) x + squareosc (hz / 2.) x
+let multiosc (param: GenerationParameter) =
+    param.Oscillators
+    |> List.sumBy (fun x ->
+        match x.Osc with
+        | Sine -> sineosc x.Freq param.Sample
+        | Triangle -> triangleosc x.Freq param.Sample
+        | Square -> squareosc x.Freq param.Sample
+        | Saw -> sawosc x.Freq param.Sample)
diff --git a/SoundGen/Program.fs b/SoundGen/Program.fs
index 338a937..d6b847e 100644
--- a/SoundGen/Program.fs
+++ b/SoundGen/Program.fs
@@ -55,9 +55,9 @@ let writeToFile (ms: MemoryStream) =
     ms.WriteTo(fs)
 
 song
-// |> Seq.map (fun x ->
-//     let x1 = sineWaveShape 2.8 2. x
-//     saturate ({ Gain = 1.0 }, x1))
+|> Seq.map (fun x ->
+    let x1 = sineWaveShape 1.5 2.5 x
+    saturate ({ Gain = 1.0 }, x1))
 //|> reverb
 |> createWAV
 |> writeToFile
diff --git a/SoundGen/Synth.fs b/SoundGen/Synth.fs
index 4cdc8bf..2190b3d 100644
--- a/SoundGen/Synth.fs
+++ b/SoundGen/Synth.fs
@@ -1,6 +1,8 @@
 module SoundGen.Synth
+
 open Settings
 open Oscillator
+open SoundGen.Oscillator
 
 let getHzBySemitones semi =
     pitchStandard * (2. ** (1. / 12.)) ** semi
@@ -32,7 +34,7 @@ let getSemitonesByNote (str: string) =
     (octave - defaultOctave - 1) * 12 + noteShift
 
 
-let freq hz duration =
+let freq hz duration (osc: OscillatorParameter list) =
     let samples =
         seq { 0.0 .. (duration * sampleRate) }
 
@@ -52,10 +54,8 @@ let freq hz duration =
     let output =
         Seq.map
             (fun x ->
-                x
-                |> sinesquareosc hz
-                |> (*) volume
-                )
+                multiosc { Oscillators = osc; Sample = x }
+                |> (*) volume)
             samples
 
     let adsrLength = Seq.length output
@@ -70,5 +70,11 @@ let freq hz duration =
 
 
 let note semitone beats =
-    let hz = getHzBySemitones semitone
-    freq hz (beats * beatDuration)
\ No newline at end of file
+    let hz = getHzBySemitones (semitone - 12.)
+
+    freq
+        hz
+        (beats * beatDuration)
+        [ { Osc = Sine; Freq = hz / 4. }
+          { Osc = Saw; Freq = (hz + 1.) }
+          { Osc = Saw; Freq = (hz - 1.3) } ]