third_party/WebKit/Source/modules/webaudio/BiquadFilterNode.cpp

/*
 * Copyright (C) 2011, Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1.  Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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#include "modules/webaudio/BiquadFilterNode.h"

#include <memory>

#include "modules/webaudio/AudioBasicProcessorHandler.h"
#include "modules/webaudio/BiquadFilterOptions.h"
#include "platform/Histogram.h"

namespace blink {

BiquadFilterNode::BiquadFilterNode(BaseAudioContext& context)
    : AudioNode(context),
      frequency_(AudioParam::Create(context,
                                    kParamTypeBiquadFilterFrequency,
                                    "BiquadFilter.frequency",
                                    350.0,
                                    0,
                                    context.sampleRate() / 2)),
      q_(AudioParam::Create(context,
                            kParamTypeBiquadFilterQ,
                            "BiquadFilter.Q",
                            1.0)),
      gain_(AudioParam::Create(context,
                               kParamTypeBiquadFilterGain,
                               "BiquadFilter.gain",
                               0.0)),
      detune_(AudioParam::Create(context,
                                 kParamTypeBiquadFilterDetune,
                                 "BiquadFilter.detune",
                                 0.0)) {
  SetHandler(AudioBasicProcessorHandler::Create(
      AudioHandler::kNodeTypeBiquadFilter, *this, context.sampleRate(),
      std::make_unique<BiquadProcessor>(context.sampleRate(), 1,
                                        frequency_->Handler(), q_->Handler(),
                                        gain_->Handler(), detune_->Handler())));

  setType("lowpass");

  // Initialize the handler so that AudioParams can be processed.
  Handler().Initialize();
}

BiquadFilterNode* BiquadFilterNode::Create(BaseAudioContext& context,
                                           ExceptionState& exception_state) {
  DCHECK(IsMainThread());

  if (context.IsContextClosed()) {
    context.ThrowExceptionForClosedState(exception_state);
    return nullptr;
  }

  return new BiquadFilterNode(context);
}

BiquadFilterNode* BiquadFilterNode::Create(BaseAudioContext* context,
                                           const BiquadFilterOptions& options,
                                           ExceptionState& exception_state) {
  BiquadFilterNode* node = Create(*context, exception_state);

  if (!node)
    return nullptr;

  node->HandleChannelOptions(options, exception_state);

  node->setType(options.type());
  node->q()->setValue(options.Q());
  node->detune()->setValue(options.detune());
  node->frequency()->setValue(options.frequency());
  node->gain()->setValue(options.gain());

  return node;
}

void BiquadFilterNode::Trace(blink::Visitor* visitor) {
  visitor->Trace(frequency_);
  visitor->Trace(q_);
  visitor->Trace(gain_);
  visitor->Trace(detune_);
  AudioNode::Trace(visitor);
}

BiquadProcessor* BiquadFilterNode::GetBiquadProcessor() const {
  return static_cast<BiquadProcessor*>(
      static_cast<AudioBasicProcessorHandler&>(Handler()).Processor());
}

String BiquadFilterNode::type() const {
  switch (
      const_cast<BiquadFilterNode*>(this)->GetBiquadProcessor()->GetType()) {
    case BiquadProcessor::kLowPass:
      return "lowpass";
    case BiquadProcessor::kHighPass:
      return "highpass";
    case BiquadProcessor::kBandPass:
      return "bandpass";
    case BiquadProcessor::kLowShelf:
      return "lowshelf";
    case BiquadProcessor::kHighShelf:
      return "highshelf";
    case BiquadProcessor::kPeaking:
      return "peaking";
    case BiquadProcessor::kNotch:
      return "notch";
    case BiquadProcessor::kAllpass:
      return "allpass";
    default:
      NOTREACHED();
      return "lowpass";
  }
}

void BiquadFilterNode::setType(const String& type) {
  // For the Q histogram, we need to change the name of the AudioParam for the
  // lowpass and highpass filters so we know to count the Q value when it is
  // set. And explicitly set the value to itself so the histograms know the
  // initial value.

  if (type == "lowpass") {
    setType(BiquadProcessor::kLowPass);
  } else if (type == "highpass") {
    setType(BiquadProcessor::kHighPass);
  } else if (type == "bandpass") {
    setType(BiquadProcessor::kBandPass);
  } else if (type == "lowshelf") {
    setType(BiquadProcessor::kLowShelf);
  } else if (type == "highshelf") {
    setType(BiquadProcessor::kHighShelf);
  } else if (type == "peaking") {
    setType(BiquadProcessor::kPeaking);
  } else if (type == "notch") {
    setType(BiquadProcessor::kNotch);
  } else if (type == "allpass") {
    setType(BiquadProcessor::kAllpass);
  }
}

bool BiquadFilterNode::setType(unsigned type) {
  if (type > BiquadProcessor::kAllpass)
    return false;

  DEFINE_STATIC_LOCAL(
      EnumerationHistogram, filter_type_histogram,
      ("WebAudio.BiquadFilter.Type", BiquadProcessor::kAllpass + 1));
  filter_type_histogram.Count(type);

  GetBiquadProcessor()->SetType(static_cast<BiquadProcessor::FilterType>(type));
  return true;
}

void BiquadFilterNode::getFrequencyResponse(
    NotShared<const DOMFloat32Array> frequency_hz,
    NotShared<DOMFloat32Array> mag_response,
    NotShared<DOMFloat32Array> phase_response) {
  DCHECK(frequency_hz);
  DCHECK(mag_response);
  DCHECK(phase_response);

  int n = std::min(
      frequency_hz.View()->length(),
      std::min(mag_response.View()->length(), phase_response.View()->length()));
  if (n) {
    GetBiquadProcessor()->GetFrequencyResponse(n, frequency_hz.View()->Data(),
                                               mag_response.View()->Data(),
                                               phase_response.View()->Data());
  }
}

}  // namespace blink