Update dpf, start of filter plugin

Signed-off-by: falkTX <[email protected]>

Makefile

@@ -22,6 +22,7 @@ plugins: dgl
 	$(MAKE) all -C plugins/Compressor
 	$(MAKE) all -C plugins/ConvolutionReverb
 	$(MAKE) all -C plugins/DevilDistortion
+	$(MAKE) all -C plugins/Filter
 # 	$(MAKE) all -C plugins/Sampler
 
 ifneq ($(CROSS_COMPILING),true)
@@ -45,6 +46,7 @@ clean:
 	$(MAKE) clean -C plugins/Compressor
 	$(MAKE) clean -C plugins/ConvolutionReverb
 	$(MAKE) clean -C plugins/DevilDistortion
+	$(MAKE) clean -C plugins/Filter
 # 	$(MAKE) clean -C plugins/Sampler
 	rm -rf bin build dpf-widgets/opengl/*.d dpf-widgets/opengl/*.o
 	rm -f 3rd-party/FFTConvolver/*.d 3rd-party/FFTConvolver/*.o

plugins/Filter/Biquad.cpp

@@ -0,0 +1,165 @@
+//
+//  Biquad.cpp
+//
+//  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/2012/11/26/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.
+//
+
+#include <math.h>
+#include "Biquad.h"
+
+Biquad::Biquad() {
+    type = bq_type_lowpass;
+    a0 = 1.0;
+    a1 = a2 = b1 = b2 = 0.0;
+    Fc = 0.50;
+    Q = 0.707;
+    peakGain = 0.0;
+    z1 = z2 = 0.0;
+}
+
+Biquad::Biquad(int type, double Fc, double Q, double peakGainDB) {
+    setBiquad(type, Fc, Q, peakGainDB);
+    z1 = z2 = 0.0;
+}
+
+Biquad::~Biquad() {
+}
+
+void Biquad::setType(int type) {
+    this->type = type;
+    calcBiquad();
+}
+
+void Biquad::setQ(double Q) {
+    this->Q = Q;
+    calcBiquad();
+}
+
+void Biquad::setFc(double Fc) {
+    this->Fc = Fc;
+    calcBiquad();
+}
+
+void Biquad::setPeakGain(double peakGainDB) {
+    this->peakGain = peakGainDB;
+    calcBiquad();
+}
+
+void Biquad::setBiquad(int type, double Fc, double Q, double peakGainDB) {
+    this->type = type;
+    this->Q = Q;
+    this->Fc = Fc;
+    setPeakGain(peakGainDB);
+}
+
+void Biquad::calcBiquad(void) {
+    double norm;
+    double V = pow(10, fabs(peakGain) / 20.0);
+    double K = tan(M_PI * Fc);
+    switch (this->type) {
+        case bq_type_lowpass:
+            norm = 1 / (1 + K / Q + K * K);
+            a0 = K * K * norm;
+            a1 = 2 * a0;
+            a2 = a0;
+            b1 = 2 * (K * K - 1) * norm;
+            b2 = (1 - K / Q + K * K) * norm;
+            break;
+
+        case bq_type_highpass:
+            norm = 1 / (1 + K / Q + K * K);
+            a0 = 1 * norm;
+            a1 = -2 * a0;
+            a2 = a0;
+            b1 = 2 * (K * K - 1) * norm;
+            b2 = (1 - K / Q + K * K) * norm;
+            break;
+
+        case bq_type_bandpass:
+            norm = 1 / (1 + K / Q + K * K);
+            a0 = K / Q * norm;
+            a1 = 0;
+            a2 = -a0;
+            b1 = 2 * (K * K - 1) * norm;
+            b2 = (1 - K / Q + K * K) * norm;
+            break;
+
+        case bq_type_notch:
+            norm = 1 / (1 + K / Q + K * K);
+            a0 = (1 + K * K) * norm;
+            a1 = 2 * (K * K - 1) * norm;
+            a2 = a0;
+            b1 = a1;
+            b2 = (1 - K / Q + K * K) * norm;
+            break;
+
+        case bq_type_peak:
+            if (peakGain >= 0) {    // boost
+                norm = 1 / (1 + 1/Q * K + K * K);
+                a0 = (1 + V/Q * K + K * K) * norm;
+                a1 = 2 * (K * K - 1) * norm;
+                a2 = (1 - V/Q * K + K * K) * norm;
+                b1 = a1;
+                b2 = (1 - 1/Q * K + K * K) * norm;
+            }
+            else {    // cut
+                norm = 1 / (1 + V/Q * K + K * K);
+                a0 = (1 + 1/Q * K + K * K) * norm;
+                a1 = 2 * (K * K - 1) * norm;
+                a2 = (1 - 1/Q * K + K * K) * norm;
+                b1 = a1;
+                b2 = (1 - V/Q * K + K * K) * norm;
+            }
+            break;
+        case bq_type_lowshelf:
+            if (peakGain >= 0) {    // boost
+                norm = 1 / (1 + sqrt(2) * K + K * K);
+                a0 = (1 + sqrt(2*V) * K + V * K * K) * norm;
+                a1 = 2 * (V * K * K - 1) * norm;
+                a2 = (1 - sqrt(2*V) * K + V * K * K) * norm;
+                b1 = 2 * (K * K - 1) * norm;
+                b2 = (1 - sqrt(2) * K + K * K) * norm;
+            }
+            else {    // cut
+                norm = 1 / (1 + sqrt(2*V) * K + V * K * K);
+                a0 = (1 + sqrt(2) * K + K * K) * norm;
+                a1 = 2 * (K * K - 1) * norm;
+                a2 = (1 - sqrt(2) * K + K * K) * norm;
+                b1 = 2 * (V * K * K - 1) * norm;
+                b2 = (1 - sqrt(2*V) * K + V * K * K) * norm;
+            }
+            break;
+        case bq_type_highshelf:
+            if (peakGain >= 0) {    // boost
+                norm = 1 / (1 + sqrt(2) * K + K * K);
+                a0 = (V + sqrt(2*V) * K + K * K) * norm;
+                a1 = 2 * (K * K - V) * norm;
+                a2 = (V - sqrt(2*V) * K + K * K) * norm;
+                b1 = 2 * (K * K - 1) * norm;
+                b2 = (1 - sqrt(2) * K + K * K) * norm;
+            }
+            else {    // cut
+                norm = 1 / (V + sqrt(2*V) * K + K * K);
+                a0 = (1 + sqrt(2) * K + K * K) * norm;
+                a1 = 2 * (K * K - 1) * norm;
+                a2 = (1 - sqrt(2) * K + K * K) * norm;
+                b1 = 2 * (K * K - V) * norm;
+                b2 = (V - sqrt(2*V) * K + K * K) * norm;
+            }
+            break;
+    }
+
+    return;
+}

plugins/Filter/Biquad.h

@@ -0,0 +1,60 @@
+//
+//  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/2012/11/26/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 peakGainDB);
+    float process(float in);
+
+protected:
+    void calcBiquad(void);
+
+    int type;
+    double a0, a1, a2, b1, b2;
+    double Fc, Q, peakGain;
+    double z1, z2;
+};
+
+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

plugins/Filter/DistrhoPluginInfo.h

@@ -0,0 +1,64 @@
+/*
+ * DISTRHO OneKnob Filter
+ * Copyright (C) 2023 Filipe Coelho <[email protected]>
+ *
+ * This program 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 2 of
+ * the License, or any later version.
+ *
+ * This program 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.
+ *
+ * For a full copy of the GNU General Public License see the LICENSE file.
+ */
+
+#pragma once
+
+#include "OneKnobPluginInfo.h"
+#include "Biquad.h"
+
+#define DISTRHO_PLUGIN_NAME    "OneKnob Filter"
+#define DISTRHO_PLUGIN_URI     "https://distrho.kx.studio/plugins/oneknob#Filter"
+#define DISTRHO_PLUGIN_CLAP_ID "studio.kx.distrho.oneknob.Filter"
+
+#define DISTRHO_PLUGIN_CLAP_FEATURES   "audio-effect", "filter", "stereo"
+#define DISTRHO_PLUGIN_LV2_CATEGORY    "lv2:FilterPlugin"
+#define DISTRHO_PLUGIN_VST3_CATEGORIES "Fx|Filter|Stereo"
+
+#ifdef __MOD_DEVICES__
+#undef DISTRHO_PLUGIN_NUM_INPUTS
+#undef DISTRHO_PLUGIN_NUM_OUTPUTS
+#define DISTRHO_PLUGIN_NUM_INPUTS 1
+#define DISTRHO_PLUGIN_NUM_OUTPUTS 1
+#endif
+
+enum Parameters {
+    kParameterType = 0,
+    kParameterFrequency,
+    kParameterQ,
+    kParameterGain,
+    kParameterBypass,
+    kParameterCount
+};
+
+enum Programs {
+    kProgramDefault,
+    kProgramCount
+};
+
+enum States {
+    kStateCount
+};
+
+static constexpr const struct OneKnobParameterRanges {
+    float min, def, max;
+} kParameterRanges[kParameterCount] = {
+    { bq_type_lowpass, bq_type_lowpass, bq_type_highshelf },
+    { 20.f, 5000.f, 20000.f },
+    { 0.f, 0.707f, 1.f },
+    { -20.f, 0.f, 20.f },
+    {}
+};

plugins/Filter/Makefile

@@ -0,0 +1,35 @@
+#!/usr/bin/make -f
+# Makefile for DISTRHO Plugins #
+# ---------------------------- #
+# Created by falkTX
+#
+
+# --------------------------------------------------------------
+# Project name, used for binaries
+
+NAME = OK-Filter
+
+# --------------------------------------------------------------
+# Files to build
+
+FILES_DSP = \
+	OneKnobPlugin.cpp \
+	Biquad.cpp
+
+# --------------------------------------------------------------
+# Do some magic
+
+include ../../dpf/Makefile.plugins.mk
+
+BUILD_CXX_FLAGS += -I../common
+BUILD_CXX_FLAGS += -I../../dpf-widgets/opengl
+LINK_FLAGS      += $(SHARED_MEMORY_LIBS)
+
+# --------------------------------------------------------------
+# Enable all possible plugin types
+
+TARGETS += lv2_sep
+
+all: $(TARGETS)
+
+# --------------------------------------------------------------