dynamictablesource.h

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#ifndef _DynSource_h
#define _DynSource_h

#include "synthfunctions.h"

// -----------------------------
//  --- SynthLab SDK File --- // 
//  ----------------------------
// -----------------------------------------------------------------------------
namespace SynthLab
{
    class DynamicTableSource : public IWavetableSource
    {
    public:
        DynamicTableSource() { }
        ~DynamicTableSource() { }

        virtual const char* getWaveformName() override
        {
            return selectedTable.waveformName;
        }

        inline virtual void selectTable(uint32_t midiNoteNumber) override
        {
            if (midiNoteNumber >= NUM_MIDI_NOTES) return;
            selectedTable = wavetableSet[midiNoteNumber];
        }

        inline virtual double readWaveTable(double normalizedPhaseInc) override
        {
            // --- two samples from table
            double wtData[2] = { 0.0, 0.0 };

            // --- location = N(fo/fs)
            double wtReadLocation = selectedTable.tableLength * normalizedPhaseInc;

            // --- split the fractional index into int.frac parts
            double dIntPart = 0.0;
            double fracPart = modf(wtReadLocation, &dIntPart);
            uint32_t readIndex = (uint32_t)dIntPart;
            uint32_t nextReadIndex = (readIndex + 1) & selectedTable.wrapMask;

            // --- two table reads
            wtData[0] = selectedTable.table.get()[readIndex];
            wtData[1] = selectedTable.table.get()[nextReadIndex];

            // --- interpolate the output
            double output = doLinearInterpolation(0.0, 1.0, wtData[0], wtData[1], fracPart);

            // --- scale as needed
            return selectedTable.outputComp * output;
        }

        virtual uint32_t getWaveTableLength() override { return selectedTable.tableLength; }


        inline void addWavetable(uint32_t startNoteNumber, uint32_t endNoteNumber, 
            std::shared_ptr<double> _table, uint32_t length, const char* name)
        {
            if (endNoteNumber >= NUM_MIDI_NOTES) return;

            DynamicWavetable wt(_table, length, name);

            for (uint32_t i = startNoteNumber; i <= endNoteNumber; i++)
            {
                wavetableSet[i] = wt;
            }

            selectedTable = wavetableSet[endNoteNumber];
        }

        inline void clearAllWavetables()
        {
            for (uint32_t i = 0; i < NUM_MIDI_NOTES; i++)
            {
                if (wavetableSet->table)
                    wavetableSet->table = nullptr;
            }
        }

    protected:
        // --- prefab table valid for all MIDI notes
        DynamicWavetable wavetableSet[NUM_MIDI_NOTES];
        DynamicWavetable selectedTable;
    };

}
#endif // definer