synth.rs 9.2 KB
Newer Older
Aske Simon Christensen's avatar
Aske Simon Christensen committed
1
2
3

use std::collections::{HashMap, VecDeque};
use std::marker::PhantomData;
4
use std::sync::RwLock;
Aske Simon Christensen's avatar
Aske Simon Christensen committed
5

6
7
8
9
10
use vst::api::{Events, Supported};
use vst::buffer::AudioBuffer;
use vst::event::{Event, MidiEvent};
use vst::host::Host;
use vst::plugin::{CanDo, Category, HostCallback, Info, Plugin};
Aske Simon Christensen's avatar
Aske Simon Christensen committed
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39

use cache::SoundCache;
use generate::{Sample, SoundGenerator, SoundParameters};


#[allow(dead_code)]
pub enum MidiCommand {
	NoteOn      { channel: u8, key: u8, velocity: u8 },
	NoteOff     { channel: u8, key: u8, velocity: u8 },
	AllNotesOff { channel: u8,          velocity: u8 },
	AllSoundOff { channel: u8,          velocity: u8 },
	Unknown
}

impl MidiCommand {
	fn fromData(data: &[u8; 3]) -> MidiCommand {
		match data[0] & 0xF0 {
			0x80 => MidiCommand::NoteOff { channel: data[0] & 0x0F, key: data[1], velocity: data[2] },
			0x90 => MidiCommand::NoteOn  { channel: data[0] & 0x0F, key: data[1], velocity: data[2] },
			0xB0 => match data[1] {
				120 => MidiCommand::AllSoundOff { channel: data[0] & 0x0F, velocity: data[2] },
				123 => MidiCommand::AllNotesOff { channel: data[0] & 0x0F, velocity: data[2] },
				_   => MidiCommand::Unknown
			},
			_    => MidiCommand::Unknown
		}
	}
}

40
pub struct TimedMidiCommand {
Aske Simon Christensen's avatar
Aske Simon Christensen committed
41
42
43
44
45
46
	time: usize,
	command: MidiCommand,
}

struct Note {
	time: usize,
47
48
	dead_time: usize,
	max_dead_time: Option<usize>,
Aske Simon Christensen's avatar
Aske Simon Christensen committed
49
50
51
52
53
54
55
56
57
	tone: u8,
	velocity: u8,
	attack: f32,
	release: f32,

	release_time: Option<usize>
}

impl Note {
58
	fn new(tone: u8, velocity: u8, attack: f32, release: f32, max_dead_time: Option<usize>) -> Note {
Aske Simon Christensen's avatar
Aske Simon Christensen committed
59
60
		Note {
			time: 0,
61
62
			dead_time: 0,
			max_dead_time: max_dead_time,
Aske Simon Christensen's avatar
Aske Simon Christensen committed
63
64
65
66
67
68
69
70
71
72
			tone: tone,
			velocity: velocity,
			attack: attack,
			release: release,

			release_time: None
		}
	}

	fn produce_sample<G: SoundGenerator>(&mut self, cache: &mut Vec<SoundCache<G>>, param: &G::Parameters, global: &G::Global) -> Sample {
73
		let wave = cache[self.tone as usize].get_sample(self.time, param, global);
74
		let amp = self.attack_amp().min(self.release_amp()) * (self.velocity as f32 / 127.0);
75
		let sample = wave * amp;
Aske Simon Christensen's avatar
Aske Simon Christensen committed
76
77
		self.time += 1;

78
79
80
81
82
83
84
		if sample.left.abs() < 0.001 && sample.right.abs() < 0.001 {
			self.dead_time += 1;
		} else {
			self.dead_time = 0;
		}

		sample
Aske Simon Christensen's avatar
Aske Simon Christensen committed
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
	}

	fn attack_amp(&self) -> f32 {
		(self.time as f32 * self.attack).min(1.0)
	}

	fn release_amp(&self) -> f32 {
		match self.release_time {
			None => 1.0,
			Some(t) => (1.0 - (self.time - t) as f32 * self.release).max(0.0)
		}
	}

	fn release(&mut self, _velocity: u8) {
		self.release_time = Some(self.time);
	}

102
	fn is_released(&self) -> bool {
Aske Simon Christensen's avatar
Aske Simon Christensen committed
103
104
105
		self.release_time.is_some()
	}

106
	fn is_alive(&self) -> bool {
107
108
109
110
111
		if let Some(max_dead_time) = self.max_dead_time {
			if self.dead_time > max_dead_time {
				return false;
			}
		}
Aske Simon Christensen's avatar
Aske Simon Christensen committed
112
113
114
115
116
117
118
119
120
121
		self.release_amp() > 0.0
	}
}


pub trait SynthInfo {
	fn get_info() -> Info;
}

pub struct SynthPlugin<G: SoundGenerator, S: SynthInfo> {
122
123
	host: Option<HostCallback>,

Aske Simon Christensen's avatar
Aske Simon Christensen committed
124
125
126
	sample_rate: f32,
	time: usize,
	notes: Vec<Note>,
127
	events: VecDeque<TimedMidiCommand>,
128
	cache: RwLock<Vec<SoundCache<G>>>,
Aske Simon Christensen's avatar
Aske Simon Christensen committed
129

130
	cached_sound_params: G::Parameters,
Aske Simon Christensen's avatar
Aske Simon Christensen committed
131
	param_values: Vec<f32>,
132
	params: RwLock<SynthPluginParameters<G>>,
Aske Simon Christensen's avatar
Aske Simon Christensen committed
133
134
135
136
137
138

	global: G::Global,

	phantom: PhantomData<S>
}

139
140
141
142
143
struct SynthPluginParameters<G: SoundGenerator> {
	map: HashMap<&'static str, f32>,
	sound_params: G::Parameters,
}

144
145
146
147
148
149
150
151
fn make_param_map(param_names: &[&'static str], param_values: &[f32]) -> HashMap<&'static str, f32> {
	let mut param_map = HashMap::new();
	for (s, v) in param_names.iter().zip(param_values) {
		param_map.insert(*s, *v);
	}
	param_map
}

Aske Simon Christensen's avatar
Aske Simon Christensen committed
152
153
impl<G: SoundGenerator, S: SynthInfo> Default for SynthPlugin<G, S> {
	fn default() -> Self {
Aske Simon Christensen's avatar
Aske Simon Christensen committed
154
155
		let param_values: Vec<f32> = G::Parameters::names().iter().map(|s| G::Parameters::default_value(s)).collect();
		let param_map = make_param_map(G::Parameters::names(), &param_values);
156
157

		let cache = (0..128).map(|tone| SoundCache::new(tone)).collect();
Aske Simon Christensen's avatar
Aske Simon Christensen committed
158
159
160

		let sample_rate = 44100.0;

161
162
163
164
165
166
167
		let sound_params = G::Parameters::build(&param_map, sample_rate);

		let params = SynthPluginParameters {
			map: param_map,
			sound_params: sound_params.clone()
		};

Aske Simon Christensen's avatar
Aske Simon Christensen committed
168
		SynthPlugin {
169
170
			host: None,

Aske Simon Christensen's avatar
Aske Simon Christensen committed
171
172
173
174
			sample_rate: sample_rate,
			time: 0,
			notes: Vec::new(),
			events: VecDeque::new(),
175
			cache: RwLock::new(cache),
Aske Simon Christensen's avatar
Aske Simon Christensen committed
176

177
			cached_sound_params: sound_params,
Aske Simon Christensen's avatar
Aske Simon Christensen committed
178
			param_values: param_values,
179
			params: RwLock::new(params),
Aske Simon Christensen's avatar
Aske Simon Christensen committed
180
181
182
183
184
185
186
187
188

			global: G::Global::default(),

			phantom: PhantomData
		}
	}
}

impl<G: SoundGenerator, S: SynthInfo> Plugin for SynthPlugin<G, S> {
189
190
191
192
193
194
195
196
	fn new(host: HostCallback) -> SynthPlugin<G, S> {
		SynthPlugin {
			host: Some(host),

			.. SynthPlugin::default()
		}
	}

Aske Simon Christensen's avatar
Aske Simon Christensen committed
197
198
199
	fn get_info(&self) -> Info {
		Info {
			presets: 0,
Aske Simon Christensen's avatar
Aske Simon Christensen committed
200
			parameters: G::Parameters::names().len() as i32,
Aske Simon Christensen's avatar
Aske Simon Christensen committed
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
			inputs: 0,
			outputs: 2,
			category: Category::Synth,
			f64_precision: false,

			.. S::get_info()
		}
	}

	fn can_do(&self, can_do: CanDo) -> Supported {
		match can_do {
			CanDo::ReceiveMidiEvent => Supported::Yes,
			_                       => Supported::No
		}
	}

217
218
219
220
221
	fn process_events(&mut self, events: &Events) {
		for e in events.events() {
			match e {
				Event::Midi(MidiEvent { delta_frames, ref data, .. }) => {
					self.events.push_back(TimedMidiCommand {
Aske Simon Christensen's avatar
Aske Simon Christensen committed
222
223
224
225
226
227
228
229
230
						time: self.time + (delta_frames as usize),
						command: MidiCommand::fromData(data)
					});
				}
				_ => {}
			}
		}
	}

231
	fn process(&mut self, buffer: &mut AudioBuffer<f32>) {
232
233
234
235
236
237
238
239
240
241
242
		{
			let params: &SynthPluginParameters<G> = &self.params.read().unwrap();
			if params.sound_params != self.cached_sound_params {
				let cache: &mut Vec<SoundCache<G>> = &mut self.cache.write().unwrap();
				self.cached_sound_params = params.sound_params.clone();
				for c in cache {
					c.invalidate();
				}
			}
		}

Aske Simon Christensen's avatar
Aske Simon Christensen committed
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
		let mut outputs = buffer.split().1;
		for i in 0..outputs[0].len() {
			while !self.events.is_empty() && self.events.front().unwrap().time == self.time {
				let event = self.events.pop_front().unwrap();
				self.handle_event(event);
			}
			let sample = self.produce_sample();
			outputs[0][i] = sample.left;
			outputs[1][i] = sample.right;
			self.time += 1;
		}
	}

	fn set_sample_rate(&mut self, rate: f32) {
		self.sample_rate = rate;
		self.build_sound_params();
	}

	fn get_parameter_name(&self, index: i32) -> String {
Aske Simon Christensen's avatar
Aske Simon Christensen committed
262
		G::Parameters::names()[index as usize].to_string()
Aske Simon Christensen's avatar
Aske Simon Christensen committed
263
264
265
	}

	fn get_parameter_text(&self, index: i32) -> String {
266
267
		let params: &SynthPluginParameters<G> = &self.params.read().unwrap();
		params.sound_params.display(G::Parameters::names()[index as usize], &params.map).0
Aske Simon Christensen's avatar
Aske Simon Christensen committed
268
269
270
	}

	fn get_parameter_label(&self, index: i32) -> String {
271
272
		let params: &SynthPluginParameters<G> = &self.params.read().unwrap();
		params.sound_params.display(G::Parameters::names()[index as usize], &params.map).1
Aske Simon Christensen's avatar
Aske Simon Christensen committed
273
274
275
276
277
278
279
280
	}

	fn get_parameter(&self, index: i32) -> f32 {
		self.param_values[index as usize]
	}

	fn set_parameter(&mut self, index: i32, value: f32) {
		self.param_values[index as usize] = value;
281
282

		if let Some(ref mut host) = self.host {
Aske Simon Christensen's avatar
Aske Simon Christensen committed
283
284
			for name in G::Parameters::influence(G::Parameters::names()[index as usize]) {
				if let Some(p) = G::Parameters::names().iter().position(|n| *n == name) {
285
286
287
288
289
290
					self.param_values[p] = infinitesimal_change(self.param_values[p]).min(1.0);
					host.automate(p as i32, self.param_values[p]);
				}
			}
		}

291
		self.build_sound_params();
Aske Simon Christensen's avatar
Aske Simon Christensen committed
292
293
294
295
	}
}

impl<G: SoundGenerator, S: SynthInfo> SynthPlugin<G, S> {
296
	fn handle_event(&mut self, event: TimedMidiCommand) {
297
		let params: &SynthPluginParameters<G> = &self.params.read().unwrap();
Aske Simon Christensen's avatar
Aske Simon Christensen committed
298
299
		match event.command {
			MidiCommand::NoteOn { key, velocity, .. } => {
300
301
				let attack = G::Parameters::attack(&params.map, self.sample_rate);
				let release = G::Parameters::release(&params.map, self.sample_rate);
302
				let note = Note::new(key, velocity, attack, release, Some(self.sample_rate as usize));
Aske Simon Christensen's avatar
Aske Simon Christensen committed
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
				self.notes.push(note);
			},
			MidiCommand::NoteOff { key, velocity, .. } => {
				for note in &mut self.notes {
					if note.tone == key && !note.is_released() {
						note.release(velocity);
						break;
					}
				}
			},
			MidiCommand::AllNotesOff { velocity, .. } => {
				for note in &mut self.notes {
					if !note.is_released() {
						note.release(velocity);
					}
				}
			},
			MidiCommand::AllSoundOff { .. } => {
				self.notes.clear();
			},
			MidiCommand::Unknown => {}
		}
	}

	fn produce_sample(&mut self) -> Sample {
328
		let cache: &mut Vec<SoundCache<G>> = &mut self.cache.write().unwrap();
Aske Simon Christensen's avatar
Aske Simon Christensen committed
329
330
331
		let mut sample: Sample = Sample::from(0.0);
		for i in (0..self.notes.len()).rev() {
			if self.notes[i].is_alive() {
332
				sample += self.notes[i].produce_sample(cache, &self.cached_sound_params, &self.global);
Aske Simon Christensen's avatar
Aske Simon Christensen committed
333
334
335
336
337
338
339
340
			} else {
				self.notes.remove(i);
			}
		}
		sample
	}

	fn build_sound_params(&mut self) {
341
342
343
		let params: &mut SynthPluginParameters<G> = &mut self.params.write().unwrap();
		params.map = make_param_map(G::Parameters::names(), &self.param_values);
		params.sound_params = G::Parameters::build(&params.map, self.sample_rate);
Aske Simon Christensen's avatar
Aske Simon Christensen committed
344
345
	}
}
346
347

fn infinitesimal_change(value: f32) -> f32 {
348
	let mut bits = value.to_bits();
349
	bits += 1;
350
	f32::from_bits(bits)
351
}