Added code

Source/NoiseVoice.cpp

@@ -0,0 +1,88 @@
+/*
+  ==============================================================================
+
+    NoiseVoice.cpp
+    Created: 11 Nov 2019 9:37:21pm
+    Author:  除村 武志
+
+  ==============================================================================
+*/
+
+#include "NoiseVoice.h"
+
+//---------------------------------------------
+//
+// Noise Voice
+//
+//---------------------------------------------
+NoiseVoice::NoiseVoice(SettingRefs *sRefs) : TonalVoice(sRefs) {}
+
+void NoiseVoice::startNote(int midiNoteNumber, float velocity, SynthesiserSound *, int currentPitchBendPosition) {
+    TonalVoice::startNote(midiNoteNumber, velocity, 0, currentPitchBendPosition);
+    switch (settingRefs->noiseAlgorithm()) {
+        case kNoiseInfinite2:
+            cycleLength = MathConstants<float>::pi / 25.0;
+            break;
+
+        case kNoiseLong:
+        case kNoiseShort:
+            cycleLength = MathConstants<float>::pi / 8.0;
+            break;
+
+        default:
+            cycleLength = MathConstants<float>::pi / 8.0;
+            break;
+    }
+}
+
+float NoiseVoice::voltageForAngle (double angle)
+{
+    // TODO: StartVoice側でangleDeltaを調整する方が良い
+    //    double dividedAngle = fmod(angle, MathConstants<float>::pi / 2.0);
+    bool isNewCycle = angle < previousAngle;
+    bool shouldUpdate = false;
+
+    if (isNewCycle)
+    {
+        shouldUpdate = true;
+    }
+    else if (nextAngle != 0)
+    {
+        if (angle >= nextAngle)
+        {
+            shouldUpdate = true;
+        }
+    }
+
+    if (shouldUpdate)
+    {
+        if (settingRefs->noiseAlgorithm() == kNoiseInfinite2)
+        {
+            currentVoltage = float (rand() % 16 - 8) / 16.;
+        }
+        else
+        {
+            int compareBitPos = settingRefs->noiseAlgorithm() == kNoiseLong ? 1 : 6;
+
+            unsigned int bit0 = rgstr & 0b0000001;
+            unsigned int compared = (rgstr & 1 << compareBitPos) >> compareBitPos;
+            unsigned int feedback = bit0 ^ compared;
+
+            rgstr = rgstr >> 1;
+
+            unsigned int mask = ~ (1 << 14);
+            unsigned int writeback = feedback << 14;
+            rgstr = (rgstr & mask) | writeback;
+
+            currentVoltage = (float)bit0 - 0.5;
+        }
+
+        nextAngle = (double) ((int) (angle / cycleLength) + 1) * cycleLength;
+
+        if (nextAngle >= MathConstants<float>::pi * 2) { nextAngle = 0; }
+    }
+
+    previousAngle = angle;
+
+    return currentVoltage;
+}