feat(dsp): add core synthesizer oscillators, wavetable and voice engine

2026-09-08 14:55:21 +02:00
parent 6e2859a1f6
commit fc9d16b302
12 changed files with 1473 additions and 0 deletions
@@ -0,0 +1,81 @@
+#pragma once
+
+#include <JuceHeader.h>
+#include "Params.h"
+
+namespace serum
+{
+
+// ===========================================================================
+// A single wavetable: 256 frames of 2048 samples each. Frames morph smoothly
+// from a simple base shape to a complex one. Lookups interpolate bilinearly
+// (across frames and within a frame). Tables are RAM-resident and generated
+// lazily by the WavetableLibrary.
+// ===========================================================================
+class Wavetable
+{
+public:
+    static constexpr int kFrames    = 256;
+    static constexpr int kTableSize = 2048;
+
+    Wavetable() = default;
+
+    juce::String name;
+    std::vector<std::vector<float>> frames;   // [frame][sample]
+
+    bool isValid() const noexcept { return (int) frames.size() == kFrames; }
+
+    void clear();
+
+    // Build a table from a per-frame harmonic amplitude function.
+    //   ampFn(frameIndex, harmonicNumber) -> amplitude  (harmonic 1 = fundamental)
+    using HarmonicAmpFn = std::function<float (int, int)>;
+    void buildHarmonic (const juce::String& name, HarmonicAmpFn ampFn, int numHarmonics = 64);
+
+    // Read the table at a fractional frame position and a phase in [0,1).
+    float read (float framePos, float phase) const noexcept;
+
+    // Read with phase wrapped and clamped frame position.
+    float readSafe (float framePos, float phase) const noexcept
+    {
+        phase -= std::floor (phase);
+        return read (juce::jlimit (0.0f, (float) kFrames - 1.001f, framePos), phase);
+    }
+
+    // Copy raw samples of a frame into a destination buffer (for the GUI).
+    void copyFrame (int frameIndex, float* dest, int numSamples) const;
+
+private:
+    static float lerp (float a, float b, float t) noexcept { return a + (b - a) * t; }
+};
+
+// ===========================================================================
+// Lazily-built library of factory wavetables. Indices map to kWavetableNames.
+// ===========================================================================
+class WavetableLibrary
+{
+public:
+    const Wavetable& getTable (int index) const;
+    int size() const noexcept { return kNumWavetables; }
+
+    // Force generation of all tables (used at prepare time).
+    void prebuild();
+
+private:
+    mutable std::array<Wavetable, kNumWavetables> tables;
+    mutable std::array<bool, kNumWavetables>      built { { false } };
+
+    void buildTable (int index) const;
+    static Wavetable makeBasic();
+    static Wavetable makeSawPwm();
+    static Wavetable makeSquareSync();
+    static Wavetable makeTriangleFold();
+    static Wavetable makeVowel();
+    static Wavetable makeOrgan();
+    static Wavetable makeWarmSaw();
+    static Wavetable makeDigital();
+    static Wavetable makeGlass();
+    static Wavetable makeBass();
+};
+
+} // namespace serum