comparison projects/d-box/PinkNoise.h @ 0:8a575ba3ab52

Initial commit.

+#ifndef _PinkNoise_H
+#define _PinkNoise_H
+
+// Technique by Larry "RidgeRat" Trammell 3/2006
+// http://home.earthlink.net/~ltrammell/tech/pinkalg.htm
+// implementation and optimization by David Lowenfels
+
+#include <cstdlib>
+#include <ctime>
+#include <stdlib.h>
+
+#define PINK_NOISE_NUM_STAGES 3
+
+class PinkNoise {
+public:
+  PinkNoise() {
+  srand ( time(NULL) ); // initialize random generator
+    clear();
+  }
+
+  void clear() {
+    for( size_t i=0; i< PINK_NOISE_NUM_STAGES; i++ )
+      state[ i ] = 0.0;
+    }
+
+  float tick() {
+    static const float RMI2 = 2.0 / float(RAND_MAX); // + 1.0; // change for range [0,1)
+    static const float offset = A[0] + A[1] + A[2];
+
+  // unrolled loop
+    float temp = float( rand() );
+    state[0] = P[0] * (state[0] - temp) + temp;
+    temp = float( rand() );
+    state[1] = P[1] * (state[1] - temp) + temp;
+    temp = float( rand() );
+    state[2] = P[2] * (state[2] - temp) + temp;
+    return ( A[0]*state[0] + A[1]*state[1] + A[2]*state[2] )*RMI2 - offset;
+  }
+
+protected:
+  float state[ PINK_NOISE_NUM_STAGES ];
+  static const float A[ PINK_NOISE_NUM_STAGES ];
+  static const float P[ PINK_NOISE_NUM_STAGES ];
+};
+
+//const float PinkNoise::A[] = { 0.02109238, 0.07113478, 0.68873558 }; // rescaled by (1+P)/(1-P)
+//const float PinkNoise::P[] = { 0.3190,  0.7756,  0.9613  };
+
+#endif