text: /*
    ==============================================================================
  
     This file is part of the JUCE examples.
     Copyright (c) 2017 - ROLI Ltd.
  
     The code included in this file is provided under the terms of the ISC license
     http://www.isc.org/downloads/software-support-policy/isc-license. Permission
     To use, copy, modify, and/or distribute this software for any purpose with or
     without fee is hereby granted provided that the above copyright notice and
     this permission notice appear in all copies.
  
     THE SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES,
     WHETHER EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR
     PURPOSE, ARE DISCLAIMED.
  
    ==============================================================================
  */
  
  /*******************************************************************************
   The block below describes the properties of this PIP. A PIP is a short snippet
   of code that can be read by the Projucer and used to generate a JUCE project.
  
   BEGIN_JUCE_PIP_METADATA
  
   name:             StateVariableFilterDemo
   version:          1.0.0
   vendor:           JUCE
   website:          http://juce.com
   description:      State variable filter demo using the DSP module.
  
   dependencies:     juce_audio_basics, juce_audio_devices, juce_audio_formats,
                     juce_audio_processors, juce_audio_utils, juce_core,
                     juce_data_structures, juce_dsp, juce_events, juce_graphics,
                     juce_gui_basics, juce_gui_extra
   exporters:        xcode_mac, vs2019, linux_make
  
   moduleFlags:      JUCE_STRICT_REFCOUNTEDPOINTER=1
  
   type:             Component
   mainClass:        StateVariableFilterDemo
  
   useLocalCopy:     1
  
   END_JUCE_PIP_METADATA
  
  *******************************************************************************/
  
  #pragma once
  
  #include "../Assets/DemoUtilities.h"
  #include "../Assets/DSPDemos_Common.h"
  
  using namespace dsp;
  
  //==============================================================================
  struct StateVariableFilterDemoDSP
  {
      void prepare (const ProcessSpec& spec)
      {
          sampleRate = spec.sampleRate;
  
          filter.state = new StateVariableFilter::Parameters<float>;
          filter.prepare (spec);
      }
  
      void process (const ProcessContextReplacing<float>& context)
      {
          filter.process (context);
      }
  
      void reset()
      {
          filter.reset();
      }
  
      void updateParameters()
      {
          if (sampleRate != 0.0)
          {
              auto cutoff    = static_cast<float> (cutoffParam.getCurrentValue());
              auto resonance = static_cast<float> (qParam.getCurrentValue());
              auto type      = static_cast<StateVariableFilter::Parameters<float>::Type> (typeParam.getCurrentSelectedID() - 1);
  
              filter.state->type = type;
              filter.state->setCutOffFrequency (sampleRate, cutoff, resonance);
          }
      }
  
      //==============================================================================
      ProcessorDuplicator<StateVariableFilter::Filter<float>,
                          StateVariableFilter::Parameters<float>> filter;
  
      ChoiceParameter typeParam {{ "Low-pass", "Band-pass", "High-pass" }, 1, "Type" };
      SliderParameter cutoffParam {{ 20.0, 20000.0 }, 0.5, 440.0f, "Cutoff", "Hz" };
      SliderParameter qParam {{ 0.3, 20.0 }, 0.5, 1.0 / MathConstants<double>::sqrt2, "Resonance" };
  
      std::vector<DSPDemoParameterBase*> parameters { &typeParam, &cutoffParam, &qParam };
      double sampleRate = 0.0;
  };
  
  struct StateVariableFilterDemo    : public Component
  {
      StateVariableFilterDemo()
      {
          addAndMakeVisible (fileReaderComponent);
          setSize (750, 500);
      }
  
      void resized() override
      {
          fileReaderComponent.setBounds (getLocalBounds());
      }
  
      AudioFileReaderComponent<StateVariableFilterDemoDSP> fileReaderComponent;
  };
  