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

Initial commit.

+//
+//  Biquad.h
+//
+//  Created by Nigel Redmon on 11/24/12
+//  EarLevel Engineering: earlevel.com
+//  Copyright 2012 Nigel Redmon
+//
+//  For a complete explanation of the Biquad code:
+//  http://www.earlevel.com/main/2012/11/25/biquad-c-source-code/
+//
+//  License:
+//
+//  This source code is provided as is, without warranty.
+//  You may copy and distribute verbatim copies of this document.
+//  You may modify and use this source code to create binary code
+//  for your own purposes, free or commercial.
+//
+
+#ifndef Biquad_h
+#define Biquad_h
+
+enum {
+    bq_type_lowpass = 0,
+    bq_type_highpass,
+    bq_type_bandpass,
+    bq_type_notch,
+    bq_type_peak,
+    bq_type_lowshelf,
+    bq_type_highshelf
+};
+
+class Biquad {
+public:
+    Biquad();
+    Biquad(int type, double Fc, double Q, double peakGainDB);
+    ~Biquad();
+    void setType(int type);
+    void setQ(double Q);
+    void setFc(double Fc);
+    void setPeakGain(double peakGainDB);
+    void setBiquad(int type, double Fc, double Q, double peakGain);
+    float process(float in);
+    
+    double getQ();
+    double getFc();
+    double getPeakGain();
+
+    double getStartingQ();
+	double getStartingFc();
+	double getStartingPeakGain();
+
+protected:
+    void calcBiquad(void);
+
+    int type;
+    double a0, a1, a2, b1, b2;
+    double Fc, Q, peakGain;
+    double startFc, startQ, startPeakGain;
+    double z1, z2;
+};
+
+inline double Biquad::getQ()
+{
+	return Q;
+}
+
+inline double Biquad::getFc()
+{
+	return Fc;
+}
+
+inline double Biquad::getPeakGain()
+{
+	return peakGain;
+}
+
+inline double Biquad::getStartingQ()
+{
+	return startQ;
+}
+
+inline double Biquad::getStartingFc()
+{
+	return startFc;
+}
+
+inline double Biquad::getStartingPeakGain()
+{
+	return startPeakGain;
+}
+
+inline float Biquad::process(float in) {
+    double out = in * a0 + z1;
+    z1 = in * a1 + z2 - b1 * out;
+    z2 = in * a2 - b2 * out;
+    return out;
+}
+
+#endif // Biquad_h