modules/webaudio/panner_node.cc

/*
 * Copyright (C) 2010, 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
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */

#include "third_party/blink/renderer/modules/webaudio/panner_node.h"

#include "base/metrics/histogram_functions.h"
#include "third_party/blink/renderer/bindings/modules/v8/v8_panner_options.h"
#include "third_party/blink/renderer/core/execution_context/execution_context.h"
#include "third_party/blink/renderer/modules/webaudio/audio_buffer_source_node.h"
#include "third_party/blink/renderer/modules/webaudio/audio_node_input.h"
#include "third_party/blink/renderer/modules/webaudio/audio_node_output.h"
#include "third_party/blink/renderer/modules/webaudio/base_audio_context.h"
#include "third_party/blink/renderer/platform/audio/hrtf_panner.h"
#include "third_party/blink/renderer/platform/bindings/exception_messages.h"
#include "third_party/blink/renderer/platform/bindings/exception_state.h"
#include "third_party/blink/renderer/platform/instrumentation/tracing/trace_event.h"
#include "third_party/blink/renderer/platform/wtf/math_extras.h"

namespace blink {

static void FixNANs(double& x) {
  if (std::isnan(x) || std::isinf(x))
    x = 0.0;
}

PannerHandler::PannerHandler(AudioNode& node,
                             float sample_rate,
                             AudioParamHandler& position_x,
                             AudioParamHandler& position_y,
                             AudioParamHandler& position_z,
                             AudioParamHandler& orientation_x,
                             AudioParamHandler& orientation_y,
                             AudioParamHandler& orientation_z)
    : AudioHandler(kNodeTypePanner, node, sample_rate),
      listener_(node.context()->listener()),
      distance_model_(DistanceEffect::kModelInverse),
      is_azimuth_elevation_dirty_(true),
      is_distance_cone_gain_dirty_(true),
      cached_azimuth_(0),
      cached_elevation_(0),
      cached_distance_cone_gain_(1.0f),
      position_x_(&position_x),
      position_y_(&position_y),
      position_z_(&position_z),
      orientation_x_(&orientation_x),
      orientation_y_(&orientation_y),
      orientation_z_(&orientation_z) {
  AddInput();
  AddOutput(2);

  // Node-specific default mixing rules.
  channel_count_ = 2;
  SetInternalChannelCountMode(kClampedMax);
  SetInternalChannelInterpretation(AudioBus::kSpeakers);

  // Explicitly set the default panning model here so that the histograms
  // include the default value.
  SetPanningModel("equalpower");

  Initialize();
}

scoped_refptr<PannerHandler> PannerHandler::Create(
    AudioNode& node,
    float sample_rate,
    AudioParamHandler& position_x,
    AudioParamHandler& position_y,
    AudioParamHandler& position_z,
    AudioParamHandler& orientation_x,
    AudioParamHandler& orientation_y,
    AudioParamHandler& orientation_z) {
  return base::AdoptRef(new PannerHandler(node, sample_rate, position_x,
                                          position_y, position_z, orientation_x,
                                          orientation_y, orientation_z));
}

PannerHandler::~PannerHandler() {
  Uninitialize();
}

// PannerNode needs a custom ProcessIfNecessary to get the process lock when
// computing PropagatesSilence() to protect processing from changes happening to
// the panning model.  This is very similar to AudioNode::ProcessIfNecessary.
void PannerHandler::ProcessIfNecessary(uint32_t frames_to_process) {
  DCHECK(Context()->IsAudioThread());

  if (!IsInitialized())
    return;

  // Ensure that we only process once per rendering quantum.
  // This handles the "fanout" problem where an output is connected to multiple
  // inputs.  The first time we're called during this time slice we process, but
  // after that we don't want to re-process, instead our output(s) will already
  // have the results cached in their bus;
  double current_time = Context()->currentTime();
  if (last_processing_time_ != current_time) {
    // important to first update this time because of feedback loops in the
    // rendering graph.
    last_processing_time_ = current_time;

    PullInputs(frames_to_process);

    bool silent_inputs = InputsAreSilent();

    {
      // Need to protect calls to PropagetesSilence (and Process) because the
      // main threda may be changing the panning model that modifies the
      // TailTime and LatencyTime methods called by PropagatesSilence.
      MutexTryLocker try_locker(process_lock_);
      if (try_locker.Locked()) {
        if (silent_inputs && PropagatesSilence()) {
          SilenceOutputs();
          // AudioParams still need to be processed so that the value can be
          // updated if there are automations or so that the upstream nodes get
          // pulled if any are connected to the AudioParam.
          ProcessOnlyAudioParams(frames_to_process);
        } else {
          // Unsilence the outputs first because the processing of the node may
          // cause the outputs to go silent and we want to propagate that hint
          // to the downstream nodes.  (For example, a Gain node with a gain of
          // 0 will want to silence its output.)
          UnsilenceOutputs();
          Process(frames_to_process);
        }
      } else {
        // We must be in the middle of changing the properties of the panner.
        // Just output silence.
        AudioBus* destination = Output(0).Bus();
        destination->Zero();
      }
    }

    if (!silent_inputs) {
      // Update |last_non_silent_time| AFTER processing this block.
      // Doing it before causes |PropagateSilence()| to be one render
      // quantum longer than necessary.
      last_non_silent_time_ =
          (Context()->CurrentSampleFrame() + frames_to_process) /
          static_cast<double>(Context()->sampleRate());
    }
  }
}

void PannerHandler::Process(uint32_t frames_to_process) {
  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("webaudio.audionode"),
               "PannerHandler::Process");

  AudioBus* destination = Output(0).Bus();

  if (!IsInitialized() || !panner_.get()) {
    destination->Zero();
    return;
  }

  scoped_refptr<AudioBus> source = Input(0).Bus();
  if (!source) {
    destination->Zero();
    return;
  }

  // The audio thread can't block on this lock, so we call tryLock() instead.
  auto listener = Listener();
  MutexTryLocker try_listener_locker(listener->ListenerLock());

  if (try_listener_locker.Locked()) {
    if (!Context()->HasRealtimeConstraint() &&
        panning_model_ == Panner::PanningModel::kHRTF) {
      // For an OfflineAudioContext, we need to make sure the HRTFDatabase
      // is loaded before proceeding.  For realtime contexts, we don't
      // have to wait.  The HRTF panner handles that case itself.
      listener->WaitForHRTFDatabaseLoaderThreadCompletion();
    }

    if ((HasSampleAccurateValues() || listener->HasSampleAccurateValues()) &&
        (IsAudioRate() || listener->IsAudioRate())) {
      // It's tempting to skip sample-accurate processing if
      // isAzimuthElevationDirty() and isDistanceConeGain() both return false.
      // But in general we can't because something may scheduled to start in the
      // middle of the rendering quantum.  On the other hand, the audible effect
      // may be small enough that we can afford to do this optimization.
      ProcessSampleAccurateValues(destination, source.get(), frames_to_process);
    } else {
      // Apply the panning effect.
      double azimuth;
      double elevation;

      // Update dirty state in case something has moved; this can happen if the
      // AudioParam for the position or orientation component is set directly.
      UpdateDirtyState();

      AzimuthElevation(&azimuth, &elevation);

      panner_->Pan(azimuth, elevation, source.get(), destination,
                   frames_to_process, InternalChannelInterpretation());

      // Get the distance and cone gain.
      float total_gain = DistanceConeGain();

      // Apply gain in-place.
      destination->CopyWithGainFrom(*destination, total_gain);
    }
  } else {
    // Too bad - The tryLock() failed.  We must be in the middle of changing the
    // properties of the panner or the listener.
    destination->Zero();
  }
}

void PannerHandler::ProcessSampleAccurateValues(AudioBus* destination,
                                                const AudioBus* source,
                                                uint32_t frames_to_process) {
  CHECK_LE(frames_to_process, audio_utilities::kRenderQuantumFrames);

  // Get the sample accurate values from all of the AudioParams, including the
  // values from the AudioListener.
  float panner_x[audio_utilities::kRenderQuantumFrames];
  float panner_y[audio_utilities::kRenderQuantumFrames];
  float panner_z[audio_utilities::kRenderQuantumFrames];

  float orientation_x[audio_utilities::kRenderQuantumFrames];
  float orientation_y[audio_utilities::kRenderQuantumFrames];
  float orientation_z[audio_utilities::kRenderQuantumFrames];

  position_x_->CalculateSampleAccurateValues(panner_x, frames_to_process);
  position_y_->CalculateSampleAccurateValues(panner_y, frames_to_process);
  position_z_->CalculateSampleAccurateValues(panner_z, frames_to_process);
  orientation_x_->CalculateSampleAccurateValues(orientation_x,
                                                frames_to_process);
  orientation_y_->CalculateSampleAccurateValues(orientation_y,
                                                frames_to_process);
  orientation_z_->CalculateSampleAccurateValues(orientation_z,
                                                frames_to_process);

  // Get the automation values from the listener.
  auto listener = Listener();
  const float* listener_x =
      listener->GetPositionXValues(audio_utilities::kRenderQuantumFrames);
  const float* listener_y =
      listener->GetPositionYValues(audio_utilities::kRenderQuantumFrames);
  const float* listener_z =
      listener->GetPositionZValues(audio_utilities::kRenderQuantumFrames);

  const float* forward_x =
      listener->GetForwardXValues(audio_utilities::kRenderQuantumFrames);
  const float* forward_y =
      listener->GetForwardYValues(audio_utilities::kRenderQuantumFrames);
  const float* forward_z =
      listener->GetForwardZValues(audio_utilities::kRenderQuantumFrames);

  const float* up_x =
      listener->GetUpXValues(audio_utilities::kRenderQuantumFrames);
  const float* up_y =
      listener->GetUpYValues(audio_utilities::kRenderQuantumFrames);
  const float* up_z =
      listener->GetUpZValues(audio_utilities::kRenderQuantumFrames);

  // Compute the azimuth, elevation, and total gains for each position.
  double azimuth[audio_utilities::kRenderQuantumFrames];
  double elevation[audio_utilities::kRenderQuantumFrames];
  float total_gain[audio_utilities::kRenderQuantumFrames];

  for (unsigned k = 0; k < frames_to_process; ++k) {
    FloatPoint3D panner_position(panner_x[k], panner_y[k], panner_z[k]);
    FloatPoint3D orientation(orientation_x[k], orientation_y[k],
                             orientation_z[k]);
    FloatPoint3D listener_position(listener_x[k], listener_y[k], listener_z[k]);
    FloatPoint3D listener_forward(forward_x[k], forward_y[k], forward_z[k]);
    FloatPoint3D listener_up(up_x[k], up_y[k], up_z[k]);

    CalculateAzimuthElevation(&azimuth[k], &elevation[k], panner_position,
                              listener_position, listener_forward, listener_up);

    // Get distance and cone gain
    total_gain[k] = CalculateDistanceConeGain(panner_position, orientation,
                                              listener_position);
  }

  // Update cached values in case automations end.
  if (frames_to_process > 0) {
    cached_azimuth_ = azimuth[frames_to_process - 1];
    cached_elevation_ = elevation[frames_to_process - 1];
    cached_distance_cone_gain_ = total_gain[frames_to_process - 1];
  }

  panner_->PanWithSampleAccurateValues(azimuth, elevation, source, destination,
                                       frames_to_process,
                                       InternalChannelInterpretation());
  destination->CopyWithSampleAccurateGainValuesFrom(*destination, total_gain,
                                                    frames_to_process);
}

void PannerHandler::ProcessOnlyAudioParams(uint32_t frames_to_process) {
  float values[audio_utilities::kRenderQuantumFrames];

  DCHECK_LE(frames_to_process, audio_utilities::kRenderQuantumFrames);

  position_x_->CalculateSampleAccurateValues(values, frames_to_process);
  position_y_->CalculateSampleAccurateValues(values, frames_to_process);
  position_z_->CalculateSampleAccurateValues(values, frames_to_process);

  orientation_x_->CalculateSampleAccurateValues(values, frames_to_process);
  orientation_y_->CalculateSampleAccurateValues(values, frames_to_process);
  orientation_z_->CalculateSampleAccurateValues(values, frames_to_process);
}

void PannerHandler::Initialize() {
  if (IsInitialized())
    return;

  auto listener = Listener();
  panner_ = Panner::Create(panning_model_, Context()->sampleRate(),
                           listener->HrtfDatabaseLoader());
  listener->AddPanner(*this);

  // The panner is already marked as dirty, so |last_position_| and
  // |last_orientation_| will bet updated on first use.  Don't need to
  // set them here.

  AudioHandler::Initialize();
}

void PannerHandler::Uninitialize() {
  if (!IsInitialized())
    return;

  panner_.reset();
  auto listener = Listener();
  if (listener) {
    // Listener may have gone in the same garbage collection cycle, which means
    // that the panner does not need to be removed.
    listener->RemovePanner(*this);
  }

  AudioHandler::Uninitialize();
}

CrossThreadPersistent<AudioListener> PannerHandler::Listener() const {
  return listener_.Lock();
}

String PannerHandler::PanningModel() const {
  switch (panning_model_) {
    case Panner::PanningModel::kEqualPower:
      return "equalpower";
    case Panner::PanningModel::kHRTF:
      return "HRTF";
  }
  NOTREACHED();
  return "equalpower";
}

void PannerHandler::SetPanningModel(const String& model) {
  // WebIDL should guarantee that we are never called with an invalid string
  // for the model.
  if (model == "equalpower")
    SetPanningModel(Panner::PanningModel::kEqualPower);
  else if (model == "HRTF")
    SetPanningModel(Panner::PanningModel::kHRTF);
  else
    NOTREACHED();
}

// This method should only be called from setPanningModel(const String&)!
bool PannerHandler::SetPanningModel(Panner::PanningModel model) {
  base::UmaHistogramEnumeration("WebAudio.PannerNode.PanningModel", model);

  if (model == Panner::PanningModel::kHRTF) {
    // Load the HRTF database asynchronously so we don't block the
    // Javascript thread while creating the HRTF database. It's ok to call
    // this multiple times; we won't be constantly loading the database over
    // and over.
    Listener()->CreateAndLoadHRTFDatabaseLoader(Context()->sampleRate());
  }

  if (!panner_.get() || model != panning_model_) {
    // We need the graph lock to secure the panner backend because
    // BaseAudioContext::Handle{Pre,Post}RenderTasks() from the audio thread
    // can touch it.
    BaseAudioContext::GraphAutoLocker context_locker(Context());

    // This synchronizes with process().
    MutexLocker process_locker(process_lock_);
    panner_ = Panner::Create(model, Context()->sampleRate(),
                             Listener()->HrtfDatabaseLoader());
    panning_model_ = model;
  }
  return true;
}

String PannerHandler::DistanceModel() const {
  switch (const_cast<PannerHandler*>(this)->distance_effect_.Model()) {
    case DistanceEffect::kModelLinear:
      return "linear";
    case DistanceEffect::kModelInverse:
      return "inverse";
    case DistanceEffect::kModelExponential:
      return "exponential";
    default:
      NOTREACHED();
      return "inverse";
  }
}

void PannerHandler::SetDistanceModel(const String& model) {
  if (model == "linear")
    SetDistanceModel(DistanceEffect::kModelLinear);
  else if (model == "inverse")
    SetDistanceModel(DistanceEffect::kModelInverse);
  else if (model == "exponential")
    SetDistanceModel(DistanceEffect::kModelExponential);
}

bool PannerHandler::SetDistanceModel(unsigned model) {
  switch (model) {
    case DistanceEffect::kModelLinear:
    case DistanceEffect::kModelInverse:
    case DistanceEffect::kModelExponential:
      if (model != distance_model_) {
        // This synchronizes with process().
        MutexLocker process_locker(process_lock_);
        distance_effect_.SetModel(
            static_cast<DistanceEffect::ModelType>(model));
        distance_model_ = model;
      }
      break;
    default:
      NOTREACHED();
      return false;
  }

  return true;
}

void PannerHandler::SetRefDistance(double distance) {
  if (RefDistance() == distance)
    return;

  // This synchronizes with process().
  MutexLocker process_locker(process_lock_);
  distance_effect_.SetRefDistance(distance);
  MarkPannerAsDirty(PannerHandler::kDistanceConeGainDirty);
}

void PannerHandler::SetMaxDistance(double distance) {
  if (MaxDistance() == distance)
    return;

  // This synchronizes with process().
  MutexLocker process_locker(process_lock_);
  distance_effect_.SetMaxDistance(distance);
  MarkPannerAsDirty(PannerHandler::kDistanceConeGainDirty);
}

void PannerHandler::SetRolloffFactor(double factor) {
  if (RolloffFactor() == factor)
    return;

  // This synchronizes with process().
  MutexLocker process_locker(process_lock_);
  distance_effect_.SetRolloffFactor(factor);
  MarkPannerAsDirty(PannerHandler::kDistanceConeGainDirty);
}

void PannerHandler::SetConeInnerAngle(double angle) {
  if (ConeInnerAngle() == angle)
    return;

  // This synchronizes with process().
  MutexLocker process_locker(process_lock_);
  cone_effect_.SetInnerAngle(angle);
  MarkPannerAsDirty(PannerHandler::kDistanceConeGainDirty);
}

void PannerHandler::SetConeOuterAngle(double angle) {
  if (ConeOuterAngle() == angle)
    return;

  // This synchronizes with process().
  MutexLocker process_locker(process_lock_);
  cone_effect_.SetOuterAngle(angle);
  MarkPannerAsDirty(PannerHandler::kDistanceConeGainDirty);
}

void PannerHandler::SetConeOuterGain(double angle) {
  if (ConeOuterGain() == angle)
    return;

  // This synchronizes with process().
  MutexLocker process_locker(process_lock_);
  cone_effect_.SetOuterGain(angle);
  MarkPannerAsDirty(PannerHandler::kDistanceConeGainDirty);
}

void PannerHandler::SetPosition(float x,
                                float y,
                                float z,
                                ExceptionState& exceptionState) {
  // This synchronizes with process().
  MutexLocker process_locker(process_lock_);

  double now = Context()->currentTime();

  position_x_->Timeline().SetValueAtTime(x, now, exceptionState);
  position_y_->Timeline().SetValueAtTime(y, now, exceptionState);
  position_z_->Timeline().SetValueAtTime(z, now, exceptionState);

  MarkPannerAsDirty(PannerHandler::kAzimuthElevationDirty |
                    PannerHandler::kDistanceConeGainDirty);
}

void PannerHandler::SetOrientation(float x,
                                   float y,
                                   float z,
                                   ExceptionState& exceptionState) {
  // This synchronizes with process().
  MutexLocker process_locker(process_lock_);

  double now = Context()->currentTime();

  orientation_x_->Timeline().SetValueAtTime(x, now, exceptionState);
  orientation_y_->Timeline().SetValueAtTime(y, now, exceptionState);
  orientation_z_->Timeline().SetValueAtTime(z, now, exceptionState);

  MarkPannerAsDirty(PannerHandler::kDistanceConeGainDirty);
}

void PannerHandler::CalculateAzimuthElevation(
    double* out_azimuth,
    double* out_elevation,
    const FloatPoint3D& position,
    const FloatPoint3D& listener_position,
    const FloatPoint3D& listener_forward,
    const FloatPoint3D& listener_up) {
  // Calculate the source-listener vector
  FloatPoint3D source_listener = position - listener_position;

  // Quick default return if the source and listener are at the same position.
  if (source_listener.IsZero()) {
    *out_azimuth = 0;
    *out_elevation = 0;
    return;
  }

  // normalize() does nothing if the length of |sourceListener| is zero.
  source_listener.Normalize();

  // Align axes
  FloatPoint3D listener_right = listener_forward.Cross(listener_up);
  listener_right.Normalize();

  FloatPoint3D listener_forward_norm = listener_forward;
  listener_forward_norm.Normalize();

  FloatPoint3D up = listener_right.Cross(listener_forward_norm);

  float up_projection = source_listener.Dot(up);

  FloatPoint3D projected_source = source_listener - up_projection * up;
  projected_source.Normalize();

  // Don't use AngleBetween here.  It produces the wrong value when one of the
  // vectors has zero length.  We know here that |projected_source| and
  // |listener_right| are "normalized", so the dot product is good enough.
  double azimuth =
      rad2deg(acos(clampTo(projected_source.Dot(listener_right), -1.0f, 1.0f)));
  FixNANs(azimuth);  // avoid illegal values

  // Source  in front or behind the listener
  double front_back = projected_source.Dot(listener_forward_norm);
  if (front_back < 0.0)
    azimuth = 360.0 - azimuth;

  // Make azimuth relative to "front" and not "right" listener vector
  if ((azimuth >= 0.0) && (azimuth <= 270.0))
    azimuth = 90.0 - azimuth;
  else
    azimuth = 450.0 - azimuth;

  // Elevation
  double elevation = 90 - rad2deg(source_listener.AngleBetween(up));
  FixNANs(elevation);  // avoid illegal values

  if (elevation > 90.0)
    elevation = 180.0 - elevation;
  else if (elevation < -90.0)
    elevation = -180.0 - elevation;

  if (out_azimuth)
    *out_azimuth = azimuth;
  if (out_elevation)
    *out_elevation = elevation;
}

float PannerHandler::CalculateDistanceConeGain(
    const FloatPoint3D& position,
    const FloatPoint3D& orientation,
    const FloatPoint3D& listener_position) {
  double listener_distance = position.DistanceTo(listener_position);
  double distance_gain = distance_effect_.Gain(listener_distance);
  double cone_gain =
      cone_effect_.Gain(position, orientation, listener_position);

  return float(distance_gain * cone_gain);
}

void PannerHandler::AzimuthElevation(double* out_azimuth,
                                     double* out_elevation) {
  DCHECK(Context()->IsAudioThread());

  auto listener = Listener();
  // Calculate new azimuth and elevation if the panner or the listener changed
  // position or orientation in any way.
  if (IsAzimuthElevationDirty() || listener->IsListenerDirty()) {
    CalculateAzimuthElevation(&cached_azimuth_, &cached_elevation_,
                              GetPosition(), listener->GetPosition(),
                              listener->Orientation(), listener->UpVector());
    is_azimuth_elevation_dirty_ = false;
  }

  *out_azimuth = cached_azimuth_;
  *out_elevation = cached_elevation_;
}

float PannerHandler::DistanceConeGain() {
  DCHECK(Context()->IsAudioThread());

  auto listener = Listener();
  // Calculate new distance and cone gain if the panner or the listener
  // changed position or orientation in any way.
  if (IsDistanceConeGainDirty() || listener->IsListenerDirty()) {
    cached_distance_cone_gain_ = CalculateDistanceConeGain(
        GetPosition(), Orientation(), listener->GetPosition());
    is_distance_cone_gain_dirty_ = false;
  }

  return cached_distance_cone_gain_;
}

void PannerHandler::MarkPannerAsDirty(unsigned dirty) {
  if (dirty & PannerHandler::kAzimuthElevationDirty)
    is_azimuth_elevation_dirty_ = true;

  if (dirty & PannerHandler::kDistanceConeGainDirty)
    is_distance_cone_gain_dirty_ = true;
}

void PannerHandler::SetChannelCount(unsigned channel_count,
                                    ExceptionState& exception_state) {
  DCHECK(IsMainThread());
  BaseAudioContext::GraphAutoLocker locker(Context());

  // A PannerNode only supports 1 or 2 channels
  if (channel_count > 0 && channel_count <= 2) {
    if (channel_count_ != channel_count) {
      channel_count_ = channel_count;
      if (InternalChannelCountMode() != kMax)
        UpdateChannelsForInputs();
    }
  } else {
    exception_state.ThrowDOMException(
        DOMExceptionCode::kNotSupportedError,
        ExceptionMessages::IndexOutsideRange<uint32_t>(
            "channelCount", channel_count, 1,
            ExceptionMessages::kInclusiveBound, 2,
            ExceptionMessages::kInclusiveBound));
  }
}

void PannerHandler::SetChannelCountMode(const String& mode,
                                        ExceptionState& exception_state) {
  DCHECK(IsMainThread());
  BaseAudioContext::GraphAutoLocker locker(Context());

  ChannelCountMode old_mode = InternalChannelCountMode();

  if (mode == "clamped-max") {
    new_channel_count_mode_ = kClampedMax;
  } else if (mode == "explicit") {
    new_channel_count_mode_ = kExplicit;
  } else if (mode == "max") {
    // This is not supported for a PannerNode, which can only handle 1 or 2
    // channels.
    exception_state.ThrowDOMException(DOMExceptionCode::kNotSupportedError,
                                      "Panner: 'max' is not allowed");
    new_channel_count_mode_ = old_mode;
  } else {
    // Do nothing for other invalid values.
    new_channel_count_mode_ = old_mode;
  }

  if (new_channel_count_mode_ != old_mode)
    Context()->GetDeferredTaskHandler().AddChangedChannelCountMode(this);
}

bool PannerHandler::HasSampleAccurateValues() const {
  return position_x_->HasSampleAccurateValues() ||
         position_y_->HasSampleAccurateValues() ||
         position_z_->HasSampleAccurateValues() ||
         orientation_x_->HasSampleAccurateValues() ||
         orientation_y_->HasSampleAccurateValues() ||
         orientation_z_->HasSampleAccurateValues();
}

bool PannerHandler::IsAudioRate() const {
  return position_x_->IsAudioRate() || position_y_->IsAudioRate() ||
         position_z_->IsAudioRate() || orientation_x_->IsAudioRate() ||
         orientation_y_->IsAudioRate() || orientation_z_->IsAudioRate();
}

void PannerHandler::UpdateDirtyState() {
  DCHECK(Context()->IsAudioThread());

  FloatPoint3D current_position = GetPosition();
  FloatPoint3D current_orientation = Orientation();

  bool has_moved = current_position != last_position_ ||
                   current_orientation != last_orientation_;

  if (has_moved) {
    last_position_ = current_position;
    last_orientation_ = current_orientation;

    MarkPannerAsDirty(PannerHandler::kAzimuthElevationDirty |
                      PannerHandler::kDistanceConeGainDirty);
  }
}

bool PannerHandler::RequiresTailProcessing() const {
  // If there's no internal panner method set up yet, assume we require tail
  // processing in case the HRTF panner is set later, which does require tail
  // processing.
  return panner_ ? panner_->RequiresTailProcessing() : true;
}

// ----------------------------------------------------------------

PannerNode::PannerNode(BaseAudioContext& context)
    : AudioNode(context),
      position_x_(
          AudioParam::Create(context,
                             Uuid(),
                             AudioParamHandler::kParamTypePannerPositionX,
                             0.0,
                             AudioParamHandler::AutomationRate::kAudio,
                             AudioParamHandler::AutomationRateMode::kVariable)),
      position_y_(
          AudioParam::Create(context,
                             Uuid(),
                             AudioParamHandler::kParamTypePannerPositionY,
                             0.0,
                             AudioParamHandler::AutomationRate::kAudio,
                             AudioParamHandler::AutomationRateMode::kVariable)),
      position_z_(
          AudioParam::Create(context,
                             Uuid(),
                             AudioParamHandler::kParamTypePannerPositionZ,
                             0.0,
                             AudioParamHandler::AutomationRate::kAudio,
                             AudioParamHandler::AutomationRateMode::kVariable)),
      orientation_x_(
          AudioParam::Create(context,
                             Uuid(),
                             AudioParamHandler::kParamTypePannerOrientationX,
                             1.0,
                             AudioParamHandler::AutomationRate::kAudio,
                             AudioParamHandler::AutomationRateMode::kVariable)),
      orientation_y_(
          AudioParam::Create(context,
                             Uuid(),
                             AudioParamHandler::kParamTypePannerOrientationY,
                             0.0,
                             AudioParamHandler::AutomationRate::kAudio,
                             AudioParamHandler::AutomationRateMode::kVariable)),
      orientation_z_(
          AudioParam::Create(context,
                             Uuid(),
                             AudioParamHandler::kParamTypePannerOrientationZ,
                             0.0,
                             AudioParamHandler::AutomationRate::kAudio,
                             AudioParamHandler::AutomationRateMode::kVariable)),
      listener_(context.listener()) {
  SetHandler(PannerHandler::Create(
      *this, context.sampleRate(), position_x_->Handler(),
      position_y_->Handler(), position_z_->Handler(), orientation_x_->Handler(),
      orientation_y_->Handler(), orientation_z_->Handler()));
}

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

  return MakeGarbageCollected<PannerNode>(context);
}

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

  if (!node)
    return nullptr;

  node->HandleChannelOptions(options, exception_state);

  node->setPanningModel(options->panningModel());
  node->setDistanceModel(options->distanceModel());

  node->positionX()->setValue(options->positionX());
  node->positionY()->setValue(options->positionY());
  node->positionZ()->setValue(options->positionZ());

  node->orientationX()->setValue(options->orientationX());
  node->orientationY()->setValue(options->orientationY());
  node->orientationZ()->setValue(options->orientationZ());

  node->setRefDistance(options->refDistance(), exception_state);
  node->setMaxDistance(options->maxDistance(), exception_state);
  node->setRolloffFactor(options->rolloffFactor(), exception_state);
  node->setConeInnerAngle(options->coneInnerAngle());
  node->setConeOuterAngle(options->coneOuterAngle());
  node->setConeOuterGain(options->coneOuterGain(), exception_state);

  return node;
}

PannerHandler& PannerNode::GetPannerHandler() const {
  return static_cast<PannerHandler&>(Handler());
}

String PannerNode::panningModel() const {
  return GetPannerHandler().PanningModel();
}

void PannerNode::setPanningModel(const String& model) {
  GetPannerHandler().SetPanningModel(model);
}

void PannerNode::setPosition(float x,
                             float y,
                             float z,
                             ExceptionState& exceptionState) {
  GetPannerHandler().SetPosition(x, y, z, exceptionState);
}

void PannerNode::setOrientation(float x,
                                float y,
                                float z,
                                ExceptionState& exceptionState) {
  GetPannerHandler().SetOrientation(x, y, z, exceptionState);
}

String PannerNode::distanceModel() const {
  return GetPannerHandler().DistanceModel();
}

void PannerNode::setDistanceModel(const String& model) {
  GetPannerHandler().SetDistanceModel(model);
}

double PannerNode::refDistance() const {
  return GetPannerHandler().RefDistance();
}

void PannerNode::setRefDistance(double distance,
                                ExceptionState& exception_state) {
  if (distance < 0) {
    exception_state.ThrowRangeError(
        ExceptionMessages::IndexExceedsMinimumBound<double>("refDistance",
                                                            distance, 0));
    return;
  }

  GetPannerHandler().SetRefDistance(distance);
}

double PannerNode::maxDistance() const {
  return GetPannerHandler().MaxDistance();
}

void PannerNode::setMaxDistance(double distance,
                                ExceptionState& exception_state) {
  if (distance <= 0) {
    exception_state.ThrowRangeError(
        ExceptionMessages::IndexExceedsMinimumBound<double>("maxDistance",
                                                            distance, 0));
    return;
  }

  GetPannerHandler().SetMaxDistance(distance);
}

double PannerNode::rolloffFactor() const {
  return GetPannerHandler().RolloffFactor();
}

void PannerNode::setRolloffFactor(double factor,
                                  ExceptionState& exception_state) {
  if (factor < 0) {
    exception_state.ThrowRangeError(
        ExceptionMessages::IndexExceedsMinimumBound<double>("rolloffFactor",
                                                            factor, 0));
    return;
  }

  GetPannerHandler().SetRolloffFactor(factor);
}

double PannerNode::coneInnerAngle() const {
  return GetPannerHandler().ConeInnerAngle();
}

void PannerNode::setConeInnerAngle(double angle) {
  GetPannerHandler().SetConeInnerAngle(angle);
}

double PannerNode::coneOuterAngle() const {
  return GetPannerHandler().ConeOuterAngle();
}

void PannerNode::setConeOuterAngle(double angle) {
  GetPannerHandler().SetConeOuterAngle(angle);
}

double PannerNode::coneOuterGain() const {
  return GetPannerHandler().ConeOuterGain();
}

void PannerNode::setConeOuterGain(double gain,
                                  ExceptionState& exception_state) {
  if (gain < 0 || gain > 1) {
    exception_state.ThrowDOMException(
        DOMExceptionCode::kInvalidStateError,
        ExceptionMessages::IndexOutsideRange<double>(
            "coneOuterGain", gain, 0, ExceptionMessages::kInclusiveBound, 1,
            ExceptionMessages::kInclusiveBound));
    return;
  }

  GetPannerHandler().SetConeOuterGain(gain);
}

void PannerNode::Trace(Visitor* visitor) const {
  visitor->Trace(position_x_);
  visitor->Trace(position_y_);
  visitor->Trace(position_z_);
  visitor->Trace(orientation_x_);
  visitor->Trace(orientation_y_);
  visitor->Trace(orientation_z_);
  visitor->Trace(listener_);
  AudioNode::Trace(visitor);
}

void PannerNode::ReportDidCreate() {
  GraphTracer().DidCreateAudioNode(this);
  GraphTracer().DidCreateAudioParam(position_x_);
  GraphTracer().DidCreateAudioParam(position_y_);
  GraphTracer().DidCreateAudioParam(position_z_);
  GraphTracer().DidCreateAudioParam(orientation_x_);
  GraphTracer().DidCreateAudioParam(orientation_y_);
  GraphTracer().DidCreateAudioParam(orientation_z_);
}

void PannerNode::ReportWillBeDestroyed() {
  GraphTracer().WillDestroyAudioParam(position_x_);
  GraphTracer().WillDestroyAudioParam(position_y_);
  GraphTracer().WillDestroyAudioParam(position_z_);
  GraphTracer().WillDestroyAudioParam(orientation_x_);
  GraphTracer().WillDestroyAudioParam(orientation_y_);
  GraphTracer().WillDestroyAudioParam(orientation_z_);
  GraphTracer().WillDestroyAudioNode(this);
}

}  // namespace blink