/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim:set ts=2 sw=2 sts=2 et cindent: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "StereoPannerNode.h"

#include "mozilla/dom/StereoPannerNodeBinding.h"

#include "AudioNodeEngine.h"

#include "AudioNodeStream.h"

#include "AudioDestinationNode.h"

#include "AlignmentUtils.h"

#include "WebAudioUtils.h"

#include "PanningUtils.h"

#include "AudioParamTimeline.h"

#include "AudioParam.h"

namespace mozilla {

namespace dom {

using namespace std;

NS_IMPL_CYCLE_COLLECTION_INHERITED(StereoPannerNode, AudioNode, mPan)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(StereoPannerNode)

NS_INTERFACE_MAP_END_INHERITING(AudioNode)

NS_IMPL_ADDREF_INHERITED(StereoPannerNode, AudioNode)

NS_IMPL_RELEASE_INHERITED(StereoPannerNode, AudioNode)

class StereoPannerNodeEngine final : public AudioNodeEngine

{

public:

  StereoPannerNodeEngine(AudioNode* aNode,

                         AudioDestinationNode* aDestination)

    : AudioNodeEngine(aNode)

    , mDestination(aDestination->Stream())

    // Keep the default value in sync with the default value in

    // StereoPannerNode::StereoPannerNode.

    , mPan(0.f)

  {

  }

  enum Parameters {

    PAN

  };

  void RecvTimelineEvent(uint32_t aIndex,

                         AudioTimelineEvent& aEvent) override

  {

    MOZ_ASSERT(mDestination);

    WebAudioUtils::ConvertAudioTimelineEventToTicks(aEvent,

                                                    mDestination);

    switch (aIndex) {

    case PAN:

      mPan.InsertEvent<int64_t>(aEvent);

      break;

    default:

      NS_ERROR("Bad StereoPannerNode TimelineParameter");

    }

  }

  void GetGainValuesForPanning(float aPanning,

                               bool aMonoToStereo,

                               float& aLeftGain,

                               float& aRightGain)

  {

    // Clamp and normalize the panning in [0; 1]

    aPanning = std::min(std::max(aPanning, -1.f), 1.f);

    if (aMonoToStereo) {

      aPanning += 1;

      aPanning /= 2;

    } else if (aPanning <= 0) {

      aPanning += 1;

    }

    aLeftGain  = cos(0.5 * M_PI * aPanning);

    aRightGain = sin(0.5 * M_PI * aPanning);

  }

  void SetToSilentStereoBlock(AudioBlock* aChunk)

  {

    for (uint32_t channel = 0; channel < 2; channel++) {

      float* samples = aChunk->ChannelFloatsForWrite(channel);

      for (uint32_t i = 0; i < WEBAUDIO_BLOCK_SIZE; i++) {

        samples[i] = 0.f;

      }

    }

  }

  void UpmixToStereoIfNeeded(const AudioBlock& aInput, AudioBlock* aOutput)

  {

    if (aInput.ChannelCount() == 2) {

      const float* inputL = static_cast<const float*>(aInput.mChannelData[0]);

      const float* inputR = static_cast<const float*>(aInput.mChannelData[1]);

      float* outputL = aOutput->ChannelFloatsForWrite(0);

      float* outputR = aOutput->ChannelFloatsForWrite(1);

      AudioBlockCopyChannelWithScale(inputL, aInput.mVolume, outputL);

      AudioBlockCopyChannelWithScale(inputR, aInput.mVolume, outputR);

    } else {

      MOZ_ASSERT(aInput.ChannelCount() == 1);

      GainMonoToStereo(aInput, aOutput, aInput.mVolume, aInput.mVolume);

    }

  }

  virtual void ProcessBlock(AudioNodeStream* aStream,

                            GraphTime aFrom,

                            const AudioBlock& aInput,

                            AudioBlock* aOutput,

                            bool *aFinished) override

  {

    // The output of this node is always stereo, no matter what the inputs are.

    MOZ_ASSERT(aInput.ChannelCount() <= 2);

    aOutput->AllocateChannels(2);

    bool monoToStereo = aInput.ChannelCount() == 1;

    if (aInput.IsNull()) {

      // If input is silent, so is the output

      SetToSilentStereoBlock(aOutput);

    } else if (mPan.HasSimpleValue()) {

      float panning = mPan.GetValue();

      // If the panning is 0.0, we can simply copy the input to the

      // output with gain applied, up-mixing to stereo if needed.

      if (panning == 0.0f) {

        UpmixToStereoIfNeeded(aInput, aOutput);

      } else {

        // Optimize the case where the panning is constant for this processing

        // block: we can just apply a constant gain on the left and right

        // channel

        float gainL, gainR;

        GetGainValuesForPanning(panning, monoToStereo, gainL, gainR);

        ApplyStereoPanning(aInput, aOutput,

                           gainL * aInput.mVolume,

                           gainR * aInput.mVolume,

                           panning <= 0);

      }

    } else {

      float computedGain[2*WEBAUDIO_BLOCK_SIZE + 4];

      bool onLeft[WEBAUDIO_BLOCK_SIZE];

      float values[WEBAUDIO_BLOCK_SIZE];

      StreamTime tick = mDestination->GraphTimeToStreamTime(aFrom);

      mPan.GetValuesAtTime(tick, values, WEBAUDIO_BLOCK_SIZE);

      float* alignedComputedGain = ALIGNED16(computedGain);

      ASSERT_ALIGNED16(alignedComputedGain);

      for (size_t counter = 0; counter < WEBAUDIO_BLOCK_SIZE; ++counter) {

        float left, right;

        GetGainValuesForPanning(values[counter], monoToStereo, left, right);

        alignedComputedGain[counter] = left * aInput.mVolume;

        alignedComputedGain[WEBAUDIO_BLOCK_SIZE + counter] = right * aInput.mVolume;

        onLeft[counter] = values[counter] <= 0;

      }

      // Apply the gain to the output buffer

      ApplyStereoPanning(aInput, aOutput, alignedComputedGain, &alignedComputedGain[WEBAUDIO_BLOCK_SIZE], onLeft);

    }

  }

  virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const override

  {

    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);

  }

  RefPtr<AudioNodeStream> mDestination;

  AudioParamTimeline mPan;

};

StereoPannerNode::StereoPannerNode(AudioContext* aContext)

  : AudioNode(aContext,

              2,

              ChannelCountMode::Clamped_max,

              ChannelInterpretation::Speakers)

  , mPan(new AudioParam(this, StereoPannerNodeEngine::PAN, "pan", 0.f, -1.f, 1.f))

{

  StereoPannerNodeEngine* engine = new StereoPannerNodeEngine(this, aContext->Destination());

  mStream = AudioNodeStream::Create(aContext, engine,

                                    AudioNodeStream::NO_STREAM_FLAGS,

                                    aContext->Graph());

}

/* static */ already_AddRefed<StereoPannerNode>

StereoPannerNode::Create(AudioContext& aAudioContext,

                         const StereoPannerOptions& aOptions,

                         ErrorResult& aRv)

{

  if (aAudioContext.CheckClosed(aRv)) {

    return nullptr;

  }

  RefPtr<StereoPannerNode> audioNode = new StereoPannerNode(&aAudioContext);

  audioNode->Initialize(aOptions, aRv);

  if (NS_WARN_IF(aRv.Failed())) {

    return nullptr;

  }

  audioNode->Pan()->SetValue(aOptions.mPan);

  return audioNode.forget();

}

size_t

StereoPannerNode::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const

{

  size_t amount = AudioNode::SizeOfExcludingThis(aMallocSizeOf);

  amount += mPan->SizeOfIncludingThis(aMallocSizeOf);

  return amount;

}

size_t

StereoPannerNode::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const

{

  return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);

}

JSObject*

StereoPannerNode::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)

{

  return StereoPannerNode_Binding::Wrap(aCx, this, aGivenProto);

}

} // namespace dom

} // namespace mozilla