un-global noise variables

synthetizer.cpp

@@ -8,8 +8,6 @@
 
 const int SAMPLE_RATE = 44100;
 const double M_TAU = 6.283185307179586476925286766559;
-uint16_t lfsr = 0xACE1u;
-unsigned bit;
 
 // Enum for waveform types
 enum Waveform {
@@ -253,6 +251,9 @@ double applyEnvelope(double time, double startTime, double duration, double volu
 }
 
 double noiseWave() {
+    static uint16_t lfsr = 0xACE1u;
+    static unsigned bit;
+
     // 16-bit Galois LFSR
     bit = ((lfsr >> 0) ^ (lfsr >> 2) ^ (lfsr >> 3) ^ (lfsr >> 5)) & 1;
     lfsr = (lfsr >> 1) | (bit << 15);