wip: oscillators

SoundGen/Oscillator.fs

@@ -0,0 +1,33 @@
+module SoundGen.Oscillator
+
+open Settings
+
+let sineosc hz x =
+    x
+    |> (*) (2. * System.Math.PI * hz / sampleRate)
+    |> sin
+
+let squareosc hz x =
+    let sign v : float = if v > 0.0 then 1. else -1.
+    x |> sineosc hz |> sign
+
+let triangleosc hz x =
+    let fullPeriodTime = 1.0 / hz
+    let localTime = x % fullPeriodTime
+    let value = localTime / fullPeriodTime
+
+    if (value < 0.25) then
+        value * 4.
+    else if (value < 0.75) then
+        2.0 - (value * 4.0)
+    else
+        value * 4. - 4.0
+        
+let sawosc hz x =
+    let fullPeriodTime = 1.0 / hz;
+    let localTime = x % fullPeriodTime
+   
+    ((localTime / fullPeriodTime) * 2. - 1.0);
+
+let sinesquareosc hz x =
+    sineosc (hz/4.) x + squareosc hz x

SoundGen/SoundGen.fsproj

@@ -7,6 +7,7 @@
 
     <ItemGroup>
         <Compile Include="Settings.fs" />
+        <Compile Include="Oscillator.fs" />
         <Compile Include="Synth.fs" />
         <Compile Include="Fx.fs" />
         <Compile Include="PCMWave.fs" />
@@ -15,6 +16,7 @@
         
         
         
+        
     </ItemGroup>
 
 </Project>

SoundGen/Synth.fs

@@ -1,5 +1,6 @@
 module SoundGen.Synth
 open Settings
+open Oscillator
 
 let getHzBySemitones semi =
     pitchStandard * (2. ** (1. / 12.)) ** semi
@@ -52,8 +53,7 @@ let freq hz duration =
         Seq.map
             (fun x ->
                 x
-                |> (*) (2. * System.Math.PI * hz / sampleRate)
+                |> sinesquareosc hz
-                |> sin
                 |> (*) volume
                 )
             samples