feat: add analog magnitude functions

README.md

@@ -4,12 +4,12 @@
 </p>
 
 # ZLEqualizer
-![pluginval](<https://github.com/ZL-Audio/ZLSplit/actions/workflows/cmake_full_test.yml/badge.svg?branch=main>)
+![pluginval](<https://github.com/ZL-Audio/ZLEqualizer/actions/workflows/cmake_full_test.yml/badge.svg?branch=main>)
 
 ZLEqualizer is an equalizer plugin.
 
 <!-- <img src="Docs/screenshot.png" width=94%> -->
- 
+
 ## Usage
 
 See the wiki for details.

source/dsp/iir_filter/analog_func.cpp

@@ -0,0 +1,49 @@
+// Copyright (C) 2023 - zsliu98
+// This file is part of ZLEqualizer
+//
+// ZLEqualizer is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+//
+// ZLEqualizer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with ZLEqualizer. If not, see <https://www.gnu.org/licenses/>.
+
+#include "analog_func.h"
+
+namespace zl_iir {
+    double AnalogFunc::getMagnitude2(std::array<double, 6> coeff, double w) {
+        auto w_2 = w * w;
+        auto denominator = std::pow(coeff[1], 2) * w_2 + std::pow(coeff[2] - coeff[0] * w_2, 2);
+        auto numerator = std::pow(coeff[4], 2) * w_2 + std::pow(coeff[5] - coeff[3] * w_2, 2);
+        return numerator / denominator;
+    }
+
+    double AnalogFunc::getLowPassMagnitude2(double w0, double q, double w) {
+        return getMagnitude2({1, w0 / q, w0 * w0, 0, 0, w0 * w0}, w);
+    }
+
+    double AnalogFunc::getHighPassMagnitude2(double w0, double q, double w) {
+        return getMagnitude2({1, w0 / q, w0 * w0, 1, 0, 0}, w);
+    }
+
+    double AnalogFunc::getBandPassMagnitude2(double w0, double q, double w) {
+        return getMagnitude2({1, w0 / q, w0 * w0, 0, w0 / q, 0}, w);
+    }
+
+    double AnalogFunc::getNotchMagnitude2(double w0, double q, double w) {
+        return getMagnitude2({1, w0 / q, w0 * w0, 1, 0, w0 * w0}, w);
+    }
+
+    double AnalogFunc::getPeakMagnitude2(double w0, double g, double q, double w) {
+        return getMagnitude2({1, w0 / std::sqrt(g) / q, w0 * w0, 1, w0 * std::sqrt(g) / q, w0 * w0}, w);
+    }
+
+    double AnalogFunc::getLowShelfMagnitude2(double w0, double g, double q, double w) {
+        auto A = std::sqrt(g);
+        return getMagnitude2({A, std::sqrt(A) * w0 / q, w0 * w0, A, A * std::sqrt(A) * w0 / q, A * w0 * w0}, w);
+    }
+
+    double AnalogFunc::getHighShelfMagnitude2(double w0, double g, double q, double w) {
+        auto A = std::sqrt(g);
+        return getMagnitude2({1, std::sqrt(A) * w0 / q, w0 * w0, A * A, A * std::sqrt(A) * w0 / q, A * w0 * w0}, w);
+    }
+}

source/dsp/iir_filter/analog_func.h

@@ -0,0 +1,38 @@
+// Copyright (C) 2023 - zsliu98
+// This file is part of ZLEqualizer
+//
+// ZLEqualizer is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+//
+// ZLEqualizer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with ZLEqualizer. If not, see <https://www.gnu.org/licenses/>.
+
+#ifndef ZLEQUALIZER_ANALOG_FUNC_H
+#define ZLEQUALIZER_ANALOG_FUNC_H
+
+#include <cmath>
+#include <array>
+
+namespace zl_iir {
+    class AnalogFunc {
+    public:
+        static double getLowPassMagnitude2(double w0, double q, double w);
+
+        static double getHighPassMagnitude2(double w0, double q, double w);
+
+        static double getBandPassMagnitude2(double w0, double q, double w);
+
+        static double getNotchMagnitude2(double w0, double q, double w);
+
+        static double getPeakMagnitude2(double w0, double g, double q, double w);
+
+        static double getLowShelfMagnitude2(double w0, double g, double q, double w);
+
+        static double getHighShelfMagnitude2(double w0, double g, double q, double w);
+
+    private:
+        static double getMagnitude2(std::array<double, 6> coeff, double w);
+    };
+}
+
+#endif //ZLEQUALIZER_ANALOG_FUNC_H

source/dsp/iir_filter/martin_coeff.cpp

@@ -0,0 +1,10 @@
+// Copyright (C) 2023 - zsliu98
+// This file is part of ZLEqualizer
+//
+// ZLEqualizer is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+//
+// ZLEqualizer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with ZLEqualizer. If not, see <https://www.gnu.org/licenses/>.
+
+#include "martin_coeff.h"

source/dsp/iir_filter/martin_coeff.h

@@ -0,0 +1,20 @@
+// Copyright (C) 2023 - zsliu98
+// This file is part of ZLEqualizer
+//
+// ZLEqualizer is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+//
+// ZLEqualizer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with ZLEqualizer. If not, see <https://www.gnu.org/licenses/>.
+
+#ifndef ZLEQUALIZER_MARTIN_COEFFS_H
+#define ZLEQUALIZER_MARTIN_COEFFS_H
+
+#include "martin_coeff.h"
+
+class MartinCoeff {
+
+};
+
+
+#endif //ZLEQUALIZER_MARTIN_COEFFS_H