wtsource.h

#ifndef _WTSource_h
#define _WTSource_h

#include "synthfunctions.h"

// -----------------------------
//  --- SynthLab SDK File --- // 
//  ----------------------------
// -----------------------------------------------------------------------------
namespace SynthLab
{
    // --- constants
    const uint32_t MAX_WAVE_TABLES = 128;

    // -------------------------------------------------
    class WavetableSource : public IWavetableSource
    {
    public:
        WavetableSource() {
            // --- clear the array of 128 table-pointers
            memset(wavetableSet, 0, NUM_MIDI_NOTES*(sizeof(double*)));
        }

        // --- clean up
        ~WavetableSource() { }

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

        // --- set the current table for note event
        inline virtual void selectTable(uint32_t midiNoteNumber)
        {
            selectedTable = wavetableSet[midiNoteNumber];
        }

        // --- read and interpolate: could add lagrange here
        inline virtual double readWaveTable(double oscClockIndex)
        {
            // --- two samples from table
            double wtData[2] = { 0.0, 0.0 };

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

            // --- 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] = uint64ToDouble(selectedTable.table[readIndex]);
            wtData[1] = uint64ToDouble(selectedTable.table[nextReadIndex]);

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

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

        // --- get len
        virtual uint32_t getWaveTableLength() { return selectedTable.tableLength; }

        // --- for init with HiResWTSet in a .h file
        inline void addWavetable(Wavetable* table, uint32_t midiNoteNumber)
        {
            //wavetableSet[midiNoteNumber] = table;
        }

    protected:
        // --- 128 wavetables
        Wavetable wavetableSet[NUM_MIDI_NOTES];
        Wavetable selectedTable;
    };

}
#endif // definer