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 | #pragma once |
26 | |
27 | #include "AudioBus.h" |
28 | #include "AudioNode.h" |
29 | #include "AudioSummingJunction.h" |
30 | #include <wtf/HashSet.h> |
31 | |
32 | namespace WebCore { |
33 | |
34 | class AudioNode; |
35 | class AudioNodeOutput; |
36 | |
37 | // An AudioNodeInput represents an input to an AudioNode and can be connected from one or more AudioNodeOutputs. |
38 | // In the case of multiple connections, the input will act as a unity-gain summing junction, mixing all the outputs. |
39 | // The number of channels of the input's bus is the maximum of the number of channels of all its connections. |
40 | |
41 | class AudioNodeInput final : public AudioSummingJunction { |
42 | WTF_MAKE_NONCOPYABLE(AudioNodeInput); |
43 | WTF_MAKE_FAST_ALLOCATED; |
44 | public: |
45 | explicit AudioNodeInput(AudioNode*); |
46 | |
47 | // AudioSummingJunction |
48 | bool canUpdateState() override { return !node()->isMarkedForDeletion(); } |
49 | void didUpdate() override; |
50 | |
51 | // Can be called from any thread. |
52 | AudioNode* node() const { return m_node; } |
53 | |
54 | // Must be called with the context's graph lock. |
55 | void connect(AudioNodeOutput*); |
56 | void disconnect(AudioNodeOutput*); |
57 | |
58 | // disable() will take the output out of the active connections list and set aside in a disabled list. |
59 | // enable() will put the output back into the active connections list. |
60 | // Must be called with the context's graph lock. |
61 | void enable(AudioNodeOutput*); |
62 | void disable(AudioNodeOutput*); |
63 | |
64 | // pull() processes all of the AudioNodes connected to us. |
65 | // In the case of multiple connections it sums the result into an internal summing bus. |
66 | // In the single connection case, it allows in-place processing where possible using inPlaceBus. |
67 | // It returns the bus which it rendered into, returning inPlaceBus if in-place processing was performed. |
68 | // Called from context's audio thread. |
69 | AudioBus* pull(AudioBus* inPlaceBus, size_t framesToProcess); |
70 | |
71 | // bus() contains the rendered audio after pull() has been called for each time quantum. |
72 | // Called from context's audio thread. |
73 | AudioBus* bus(); |
74 | |
75 | // updateInternalBus() updates m_internalSummingBus appropriately for the number of channels. |
76 | // This must be called when we own the context's graph lock in the audio thread at the very start or end of the render quantum. |
77 | void updateInternalBus(); |
78 | |
79 | // The number of channels of the connection with the largest number of channels. |
80 | unsigned numberOfChannels() const; |
81 | |
82 | private: |
83 | AudioNode* m_node; |
84 | |
85 | // m_disabledOutputs contains the AudioNodeOutputs which are disabled (will not be processed) by the audio graph rendering. |
86 | // But, from JavaScript's perspective, these outputs are still connected to us. |
87 | // Generally, these represent disabled connections from "notes" which have finished playing but are not yet garbage collected. |
88 | HashSet<AudioNodeOutput*> m_disabledOutputs; |
89 | |
90 | // Called from context's audio thread. |
91 | AudioBus* internalSummingBus(); |
92 | void sumAllConnections(AudioBus* summingBus, size_t framesToProcess); |
93 | |
94 | RefPtr<AudioBus> m_internalSummingBus; |
95 | }; |
96 | |
97 | } // namespace WebCore |
98 | |