1 files changed, 170 insertions, 0 deletions
diff --git a/dom/media/webaudio/AudioParam.cpp b/dom/media/webaudio/AudioParam.cpp
new file mode 100644
index 0000000000..58d3b225c5
--- /dev/null
+++ b/dom/media/webaudio/AudioParam.cpp
@@ -0,0 +1,170 @@
+/* -*- 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 "AudioParam.h"
+#include "mozilla/dom/AudioParamBinding.h"
+#include "AudioNodeEngine.h"
+#include "AudioNodeTrack.h"
+#include "AudioContext.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(AudioParam)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(AudioParam)
+  tmp->DisconnectFromGraphAndDestroyTrack();
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mNode)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(AudioParam)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mNode)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTING_NATIVE_ADDREF(AudioParam)
+NS_IMPL_CYCLE_COLLECTING_NATIVE_RELEASE(AudioParam)
+
+AudioParam::AudioParam(AudioNode* aNode, uint32_t aIndex,
+                       const nsAString& aName, float aDefaultValue,
+                       float aMinValue, float aMaxValue)
+    : AudioParamTimeline(aDefaultValue),
+      mNode(aNode),
+      mName(aName),
+      mIndex(aIndex),
+      mDefaultValue(aDefaultValue),
+      mMinValue(aMinValue),
+      mMaxValue(aMaxValue) {}
+
+AudioParam::~AudioParam() { DisconnectFromGraphAndDestroyTrack(); }
+
+JSObject* AudioParam::WrapObject(JSContext* aCx,
+                                 JS::Handle<JSObject*> aGivenProto) {
+  return AudioParam_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+void AudioParam::DisconnectFromGraphAndDestroyTrack() {
+  MOZ_ASSERT(mRefCnt.get() > mInputNodes.Length(),
+             "Caller should be holding a reference or have called "
+             "mRefCnt.stabilizeForDeletion()");
+
+  while (!mInputNodes.IsEmpty()) {
+    RefPtr<AudioNode> input = mInputNodes.PopLastElement().mInputNode;
+    input->RemoveOutputParam(this);
+  }
+
+  if (mNodeTrackPort) {
+    mNodeTrackPort->Destroy();
+    mNodeTrackPort = nullptr;
+  }
+
+  if (mTrack) {
+    mTrack->Destroy();
+    mTrack = nullptr;
+  }
+}
+
+mozilla::MediaTrack* AudioParam::GetTrack() const { return mTrack; }
+
+mozilla::MediaTrack* AudioParam::Track() {
+  if (mTrack) {
+    return mTrack;
+  }
+
+  AudioNodeEngine* engine = new AudioNodeEngine(nullptr);
+  mTrack = AudioNodeTrack::Create(mNode->Context(), engine,
+                                  AudioNodeTrack::NO_TRACK_FLAGS,
+                                  mNode->Context()->Graph());
+
+  // Force the input to have only one channel, and make it down-mix using
+  // the speaker rules if needed.
+  mTrack->SetChannelMixingParametersImpl(1, ChannelCountMode::Explicit,
+                                         ChannelInterpretation::Speakers);
+  // Mark as an AudioParam helper track
+  mTrack->SetAudioParamHelperTrack();
+
+  // Setup the AudioParam's track as an input to the owner AudioNode's track
+  AudioNodeTrack* nodeTrack = mNode->GetTrack();
+  if (nodeTrack) {
+    mNodeTrackPort = nodeTrack->AllocateInputPort(mTrack);
+  }
+
+  // Send the track to the timeline on the MTG side.
+  AudioParamEvent event(mTrack);
+  SendEventToEngine(event);
+
+  return mTrack;
+}
+
+static const char* ToString(AudioTimelineEvent::Type aType) {
+  switch (aType) {
+    case AudioTimelineEvent::SetValue:
+      return "SetValue";
+    case AudioTimelineEvent::SetValueAtTime:
+      return "SetValueAtTime";
+    case AudioTimelineEvent::LinearRamp:
+      return "LinearRamp";
+    case AudioTimelineEvent::ExponentialRamp:
+      return "ExponentialRamp";
+    case AudioTimelineEvent::SetTarget:
+      return "SetTarget";
+    case AudioTimelineEvent::SetValueCurve:
+      return "SetValueCurve";
+    case AudioTimelineEvent::Track:
+      return "Track";
+    case AudioTimelineEvent::Cancel:
+      return "Cancel";
+    default:
+      return "unknown AudioTimelineEvent";
+  }
+}
+
+void AudioParam::SendEventToEngine(const AudioParamEvent& aEvent) {
+  WEB_AUDIO_API_LOG(
+      "%f: %s for %u %s %s=%g time=%f %s=%g", GetParentObject()->CurrentTime(),
+      NS_ConvertUTF16toUTF8(mName).get(), ParentNodeId(),
+      ToString(aEvent.mType),
+      aEvent.mType == AudioTimelineEvent::SetValueCurve ? "length" : "value",
+      aEvent.mType == AudioTimelineEvent::SetValueCurve
+          ? static_cast<double>(aEvent.CurveLength())
+          : static_cast<double>(aEvent.NominalValue()),
+      aEvent.Time<double>(),
+      aEvent.mType == AudioTimelineEvent::SetValueCurve ? "duration"
+                                                        : "constant",
+      aEvent.mType == AudioTimelineEvent::SetValueCurve
+          ? aEvent.Duration()
+          : aEvent.TimeConstant());
+
+  AudioNodeTrack* track = mNode->GetTrack();
+  if (track) {
+    track->SendTimelineEvent(mIndex, aEvent);
+  }
+}
+
+void AudioParam::CleanupOldEvents() {
+  MOZ_ASSERT(NS_IsMainThread());
+  double currentTime = mNode->Context()->CurrentTime();
+
+  CleanupEventsOlderThan(currentTime);
+}
+
+float AudioParamTimeline::AudioNodeInputValue(size_t aCounter) const {
+  MOZ_ASSERT(mTrack);
+
+  // If we have a chunk produced by the AudioNode inputs to the AudioParam,
+  // get its value now.  We use aCounter to tell us which frame of the last
+  // AudioChunk to look at.
+  float audioNodeInputValue = 0.0f;
+  const AudioBlock& lastAudioNodeChunk = mTrack->LastChunks()[0];
+  if (!lastAudioNodeChunk.IsNull()) {
+    MOZ_ASSERT(lastAudioNodeChunk.GetDuration() == WEBAUDIO_BLOCK_SIZE);
+    audioNodeInputValue =
+        static_cast<const float*>(lastAudioNodeChunk.mChannelData[0])[aCounter];
+    audioNodeInputValue *= lastAudioNodeChunk.mVolume;
+  }
+
+  return audioNodeInputValue;
+}
+
+}  // namespace mozilla::dom