IPlugExamples/IPlugMouseTest/IPlugMouseTestDSP.h

   1 #ifndef __IPLUGMOUSETESTDSP_H__
   2 #define __IPLUGMOUSETESTDSP_H__
   3
   4 inline double midi2CPS(double pitch)
   5 {
   6   return 440. * pow(2., (pitch - 69.) / 12.);
   7 }
   8
   9 inline double wrap(double x, double low = 0., double high = 1.)
  10 {
  11   while (x >= high) x -= high;
  12   while (x < low)  x += high - low;
  13
  14   return x;
  15 }
  16
  17 inline double lerp(double phase, const double* buffer, unsigned long int mask)
  18 {
  19   const int intPart = (int) phase;
  20   const double fracPart = phase-intPart;
  21
  22   const double a = buffer[intPart & mask];
  23   const double b = buffer[(intPart+1) & mask];
  24
  25   return a + (b - a) * fracPart;
  26 }
  27
  28 struct CWTOscState
  29 {
  30   double mPhase;        // float phase (goes between 0. and 1.)
  31   double mPhaseIncr;    // freq * mPhaseStep
  32
  33   CWTOscState()
  34   {
  35     mPhase = 0.;
  36     mPhaseIncr = 0.;
  37   }
  38
  39 } WDL_FIXALIGN;
  40
  41 class CWTOsc
  42 {
  43 protected:
  44   const double* mLUT;           // pointer to waveform lookup table, const because the oscilator doesn't change the table data
  45   unsigned long int mLUTSize;   // wavetable size
  46   unsigned long int mLUTSizeM;  // wavetable Mask (size -1)
  47   double mLUTSizeF;             // float version
  48
  49 public:
  50
  51   CWTOsc(const double* LUT, unsigned long int LUTSize)
  52   {
  53     setLUT(LUT, LUTSize);
  54   }
  55
  56   ~CWTOsc() {}
  57
  58   void setLUT(const double* LUT, unsigned long int LUTSize)
  59   {
  60     mLUTSize = LUTSize;
  61     mLUTSizeM = LUTSize-1;
  62     mLUTSizeF = (double) LUTSize;
  63     mLUT = LUT;
  64   }
  65
  66   inline double process(CWTOscState* pState)
  67   {
  68     pState->mPhase = wrap(pState->mPhase, 0., 1.);
  69     const double output = lerp(pState->mPhase * mLUTSizeF, mLUT, mLUTSizeM);
  70     pState->mPhase += pState->mPhaseIncr;
  71
  72     return output;
  73   }
  74
  75 } WDL_FIXALIGN;
  76
  77 #endif // __IPLUGMOUSETESTDSP_H__