OpenShot Library | OpenShotAudio 0.2.2
juce_MPESynthesiserVoice.h
1
2/** @weakgroup juce_audio_basics-mpe
3 * @{
4 */
5/*
6 ==============================================================================
7
8 This file is part of the JUCE library.
9 Copyright (c) 2017 - ROLI Ltd.
10
11 JUCE is an open source library subject to commercial or open-source
12 licensing.
13
14 The code included in this file is provided under the terms of the ISC license
15 http://www.isc.org/downloads/software-support-policy/isc-license. Permission
16 To use, copy, modify, and/or distribute this software for any purpose with or
17 without fee is hereby granted provided that the above copyright notice and
18 this permission notice appear in all copies.
19
20 JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
21 EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
22 DISCLAIMED.
23
24 ==============================================================================
25*/
26
27namespace juce
28{
29
30//==============================================================================
31/**
32 Represents an MPE voice that an MPESynthesiser can use to play a sound.
33
34 A voice plays a single sound at a time, and a synthesiser holds an array of
35 voices so that it can play polyphonically.
36
37 @see MPESynthesiser, MPENote
38
39 @tags{Audio}
40*/
42{
43public:
44 //==============================================================================
45 /** Constructor. */
47
48 /** Destructor. */
49 virtual ~MPESynthesiserVoice();
50
51 /** Returns the MPENote that this voice is currently playing.
52 Returns an invalid MPENote if no note is playing
53 (you can check this using MPENote::isValid() or MPEVoice::isActive()).
54 */
55 MPENote getCurrentlyPlayingNote() const noexcept { return currentlyPlayingNote; }
56
57 /** Returns true if the voice is currently playing the given MPENote
58 (as identified by the note's initial note number and MIDI channel).
59 */
60 bool isCurrentlyPlayingNote (MPENote note) const noexcept;
61
62 /** Returns true if this voice is currently busy playing a sound.
63 By default this just checks whether getCurrentlyPlayingNote()
64 returns a valid MPE note, but can be overridden for more advanced checking.
65 */
66 virtual bool isActive() const { return currentlyPlayingNote.isValid(); }
67
68 /** Returns true if a voice is sounding in its release phase. **/
69 bool isPlayingButReleased() const noexcept;
70
71 /** Called by the MPESynthesiser to let the voice know that a new note has started on it.
72 This will be called during the rendering callback, so must be fast and thread-safe.
73 */
74 virtual void noteStarted() = 0;
75
76 /** Called by the MPESynthesiser to let the voice know that its currently playing note has stopped.
77 This will be called during the rendering callback, so must be fast and thread-safe.
78
79 If allowTailOff is false or the voice doesn't want to tail-off, then it must stop all
80 sound immediately, and must call clearCurrentNote() to reset the state of this voice
81 and allow the synth to reassign it another sound.
82
83 If allowTailOff is true and the voice decides to do a tail-off, then it's allowed to
84 begin fading out its sound, and it can stop playing until it's finished. As soon as it
85 finishes playing (during the rendering callback), it must make sure that it calls
86 clearCurrentNote().
87 */
88 virtual void noteStopped (bool allowTailOff) = 0;
89
90 /** Called by the MPESynthesiser to let the voice know that its currently playing note
91 has changed its pressure value.
92 This will be called during the rendering callback, so must be fast and thread-safe.
93 */
94 virtual void notePressureChanged() = 0;
95
96 /** Called by the MPESynthesiser to let the voice know that its currently playing note
97 has changed its pitchbend value.
98 This will be called during the rendering callback, so must be fast and thread-safe.
99
100 Note: You can call currentlyPlayingNote.getFrequencyInHertz() to find out the effective frequency
101 of the note, as a sum of the initial note number, the per-note pitchbend and the master pitchbend.
102 */
103 virtual void notePitchbendChanged() = 0;
104
105 /** Called by the MPESynthesiser to let the voice know that its currently playing note
106 has changed its timbre value.
107 This will be called during the rendering callback, so must be fast and thread-safe.
108 */
109 virtual void noteTimbreChanged() = 0;
110
111 /** Called by the MPESynthesiser to let the voice know that its currently playing note
112 has changed its key state.
113 This typically happens when a sustain or sostenuto pedal is pressed or released (on
114 an MPE channel relevant for this note), or if the note key is lifted while the sustained
115 or sostenuto pedal is still held down.
116 This will be called during the rendering callback, so must be fast and thread-safe.
117 */
118 virtual void noteKeyStateChanged() = 0;
119
120 /** Renders the next block of data for this voice.
121
122 The output audio data must be added to the current contents of the buffer provided.
123 Only the region of the buffer between startSample and (startSample + numSamples)
124 should be altered by this method.
125
126 If the voice is currently silent, it should just return without doing anything.
127
128 If the sound that the voice is playing finishes during the course of this rendered
129 block, it must call clearCurrentNote(), to tell the synthesiser that it has finished.
130
131 The size of the blocks that are rendered can change each time it is called, and may
132 involve rendering as little as 1 sample at a time. In between rendering callbacks,
133 the voice's methods will be called to tell it about note and controller events.
134 */
135 virtual void renderNextBlock (AudioBuffer<float>& outputBuffer,
136 int startSample,
137 int numSamples) = 0;
138
139 /** Renders the next block of 64-bit data for this voice.
140
141 Support for 64-bit audio is optional. You can choose to not override this method if
142 you don't need it (the default implementation simply does nothing).
143 */
144 virtual void renderNextBlock (AudioBuffer<double>& /*outputBuffer*/,
145 int /*startSample*/,
146 int /*numSamples*/) {}
147
148 /** Changes the voice's reference sample rate.
149
150 The rate is set so that subclasses know the output rate and can set their pitch
151 accordingly.
152
153 This method is called by the synth, and subclasses can access the current rate with
154 the currentSampleRate member.
155 */
156 virtual void setCurrentSampleRate (double newRate) { currentSampleRate = newRate; }
157
158 /** Returns the current target sample rate at which rendering is being done.
159 Subclasses may need to know this so that they can pitch things correctly.
160 */
161 double getSampleRate() const noexcept { return currentSampleRate; }
162
163 /** This will be set to an incrementing counter value in MPESynthesiser::startVoice()
164 and can be used to determine the order in which voices started.
165 */
166 uint32 noteOnTime = 0;
167
168protected:
169 //==============================================================================
170 /** Resets the state of this voice after a sound has finished playing.
171
172 The subclass must call this when it finishes playing a note and becomes available
173 to play new ones.
174
175 It must either call it in the stopNote() method, or if the voice is tailing off,
176 then it should call it later during the renderNextBlock method, as soon as it
177 finishes its tail-off.
178
179 It can also be called at any time during the render callback if the sound happens
180 to have finished, e.g. if it's playing a sample and the sample finishes.
181 */
182 void clearCurrentNote() noexcept;
183
184 //==============================================================================
185 double currentSampleRate = 0.0;
186 MPENote currentlyPlayingNote;
187
188private:
189 //==============================================================================
190 friend class MPESynthesiser;
191
192 JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MPESynthesiserVoice)
193};
194
195} // namespace juce
196
197/** @}*/
A multi-channel buffer containing floating point audio samples.
Represents an MPE voice that an MPESynthesiser can use to play a sound.
virtual void setCurrentSampleRate(double newRate)
Changes the voice's reference sample rate.
MPENote getCurrentlyPlayingNote() const noexcept
Returns the MPENote that this voice is currently playing.
double getSampleRate() const noexcept
Returns the current target sample rate at which rendering is being done.
virtual bool isActive() const
Returns true if this voice is currently busy playing a sound.
Base class for an MPE-compatible musical device that can play sounds.
#define JUCE_API
This macro is added to all JUCE public class declarations.
This struct represents a playing MPE note.
Definition: juce_MPENote.h:44