1/*
2 * Copyright (C) 2010, Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1.  Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2.  Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#include "config.h"
26
27#if ENABLE(WEB_AUDIO)
28
29#include "AudioDestinationNode.h"
30
31#include "AudioContext.h"
32#include "AudioNodeInput.h"
33#include "AudioNodeOutput.h"
34#include "AudioUtilities.h"
35#include "DenormalDisabler.h"
36
37namespace WebCore {
38
39AudioDestinationNode::AudioDestinationNode(AudioContext* context, float sampleRate)
40    : AudioNode(context, sampleRate)
41    , m_currentSampleFrame(0)
42{
43    addInput(std::make_unique<AudioNodeInput>(this));
44
45    setNodeType(NodeTypeDestination);
46}
47
48AudioDestinationNode::~AudioDestinationNode()
49{
50    uninitialize();
51}
52
53void AudioDestinationNode::render(AudioBus* sourceBus, AudioBus* destinationBus, size_t numberOfFrames)
54{
55    // We don't want denormals slowing down any of the audio processing
56    // since they can very seriously hurt performance.
57    // This will take care of all AudioNodes because they all process within this scope.
58    DenormalDisabler denormalDisabler;
59
60    context()->setAudioThread(currentThread());
61
62    if (!context()->isRunnable()) {
63        destinationBus->zero();
64        return;
65    }
66
67    if (context()->userGestureRequiredForAudioStart()) {
68        destinationBus->zero();
69        return;
70    }
71
72    if (context()->pageConsentRequiredForAudioStart()) {
73        destinationBus->zero();
74        return;
75    }
76
77    // Let the context take care of any business at the start of each render quantum.
78    context()->handlePreRenderTasks();
79
80    // Prepare the local audio input provider for this render quantum.
81    if (sourceBus)
82        m_localAudioInputProvider.set(sourceBus);
83
84    // This will cause the node(s) connected to us to process, which in turn will pull on their input(s),
85    // all the way backwards through the rendering graph.
86    AudioBus* renderedBus = input(0)->pull(destinationBus, numberOfFrames);
87
88    if (!renderedBus)
89        destinationBus->zero();
90    else if (renderedBus != destinationBus) {
91        // in-place processing was not possible - so copy
92        destinationBus->copyFrom(*renderedBus);
93    }
94
95    // Process nodes which need a little extra help because they are not connected to anything, but still need to process.
96    context()->processAutomaticPullNodes(numberOfFrames);
97
98    // Let the context take care of any business at the end of each render quantum.
99    context()->handlePostRenderTasks();
100
101    // Advance current sample-frame.
102    m_currentSampleFrame += numberOfFrames;
103}
104
105} // namespace WebCore
106
107#endif // ENABLE(WEB_AUDIO)
108