tunes 1.1.0

A music composition, synthesis, and audio generation library
Documentation 
1
2
3
4
5
6
7
8
9
10
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
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314

//! Cymbal sounds
//!
//! All cymbal types including hi-hats, crashes, rides, and specialty cymbals.

use super::noise;

/// Generate a hi-hat sample (high frequency noise burst)
pub(super) fn hihat_sample(sample_index: usize, sample_rate: f32, closed: bool) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = if closed { 0.05 } else { 0.15 }; // Closed vs open

    if t > duration {
        return 0.0;
    }

    let noise_val = noise(sample_index as f32);

    // High-pass filtered noise (simulate by mixing high freq sine with noise_val)
    let high_tone = (2.0 * std::f32::consts::PI * 8000.0 * t).sin();
    let filtered_noise = noise_val * 0.8 + high_tone * 0.2;

    // Very fast decay
    let decay_rate = if closed { 40.0 } else { 15.0 };
    let envelope = (-t * decay_rate).exp();

    filtered_noise * envelope * 0.3
}

/// Half-open hi-hat - Between closed and open
pub(super) fn hihat_half_open_sample(sample_index: usize, sample_rate: f32) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = 0.1;

    if t > duration {
        return 0.0;
    }

    // Medium decay - between closed and open
    let envelope = (-t * 18.0).exp();

    // Mix of frequencies for half-open character
    let noise_val = noise(t * 9000.0);
    let metallic1 = (2.0 * std::f32::consts::PI * 7500.0 * t).sin() * 0.2;
    let metallic2 = (2.0 * std::f32::consts::PI * 10200.0 * t).sin() * 0.15;

    (noise_val * 0.65 + metallic1 + metallic2) * envelope * 0.5
}

/// Sizzle hi-hat - Lots of high-frequency content
pub(super) fn hihat_sizzle_sample(sample_index: usize, sample_rate: f32) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = 0.2;

    if t > duration {
        return 0.0;
    }

    let envelope = (-t * 10.0).exp();

    // Very high frequency content for sizzle
    let noise_val = noise(t * 13000.0) * 0.7;
    let sizzle1 = (2.0 * std::f32::consts::PI * 12000.0 * t).sin() * 0.15;
    let sizzle2 = (2.0 * std::f32::consts::PI * 15500.0 * t).sin() * 0.1;

    (noise_val + sizzle1 + sizzle2) * envelope * 0.45
}

/// Pedal hi-hat - Foot pedal "chick" sound
pub(super) fn hihat_pedal_sample(sample_index: usize, sample_rate: f32) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = 0.08;

    if t > duration {
        return 0.0;
    }

    // Very fast decay for tight chick sound
    let envelope = (-t * 40.0).exp();

    // High-frequency metallic content with noise
    let noise_val = noise(t * 10000.0);
    let high_freq = (2.0 * std::f32::consts::PI * 8000.0 * t).sin() * 0.3;

    (noise_val * 0.7 + high_freq) * envelope * 0.4
}

/// Generate a crash cymbal sample (bright noise with long decay)
pub(super) fn crash_sample(sample_index: usize, sample_rate: f32) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = 1.5;

    if t > duration {
        return 0.0;
    }

    let noise_val = noise(sample_index as f32);

    // Mix with high frequency tones for brightness
    let bright1 = (2.0 * std::f32::consts::PI * 7000.0 * t).sin();
    let bright2 = (2.0 * std::f32::consts::PI * 9000.0 * t).sin();

    // Slow decay
    let envelope = (-t * 2.0).exp();

    (noise_val * 0.7 + bright1 * 0.15 + bright2 * 0.15) * envelope * 0.35
}

/// Crash cymbal 2 - Second crash variation
pub(super) fn crash2_sample(sample_index: usize, sample_rate: f32) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = 1.8;

    if t > duration {
        return 0.0;
    }

    // Slower decay than crash 1, slightly different tonality
    let envelope = (-t * 1.5).exp();

    // Inharmonic partials at different frequencies than crash 1
    let freq1 = (2.0 * std::f32::consts::PI * 520.0 * t).sin();
    let freq2 = (2.0 * std::f32::consts::PI * 780.0 * t).sin();
    let freq3 = (2.0 * std::f32::consts::PI * 1150.0 * t).sin();
    let freq4 = (2.0 * std::f32::consts::PI * 1680.0 * t).sin();

    let noise_val = noise(t * 5000.0) * 0.5;
    let tonal = (freq1 + freq2 + freq3 + freq4) * 0.2;

    (noise_val + tonal) * envelope * 0.6
}

/// Crash short - Quick crash, gated
pub(super) fn crash_short_sample(sample_index: usize, sample_rate: f32) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = 0.5;

    if t > duration {
        return 0.0;
    }

    // Fast decay for gated crash
    let envelope = (-t * 6.0).exp();

    // Inharmonic partials
    let freq1 = (2.0 * std::f32::consts::PI * 480.0 * t).sin();
    let freq2 = (2.0 * std::f32::consts::PI * 720.0 * t).sin();
    let freq3 = (2.0 * std::f32::consts::PI * 1080.0 * t).sin();

    let noise_val = noise(t * 5500.0) * 0.5;
    let tonal = (freq1 + freq2 + freq3) * 0.2;

    (noise_val + tonal) * envelope * 0.6
}

/// Generate a ride cymbal sample (sustained bright noise_val)
pub(super) fn ride_sample(sample_index: usize, sample_rate: f32) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = 0.8;

    if t > duration {
        return 0.0;
    }

    let noise_val = noise(sample_index as f32);

    // Mix with metallic frequencies
    let metallic1 = (2.0 * std::f32::consts::PI * 5000.0 * t).sin();
    let metallic2 = (2.0 * std::f32::consts::PI * 7000.0 * t).sin();

    // Moderate decay
    let envelope = (-t * 3.5).exp();

    (noise_val * 0.6 + metallic1 * 0.2 + metallic2 * 0.2) * envelope * 0.25
}

/// Generate a ride bell sample (metallic ping)
pub(super) fn ride_bell_sample(sample_index: usize, sample_rate: f32) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = 0.8;

    if t > duration {
        return 0.0;
    }

    // Higher pitched than ride, around 4000Hz
    let freq = 4000.0;

    // Lots of inharmonic partials for bell character
    let fundamental = (2.0 * std::f32::consts::PI * freq * t).sin();
    let partial2 = (2.0 * std::f32::consts::PI * freq * 2.4 * t).sin() * 0.6;
    let partial3 = (2.0 * std::f32::consts::PI * freq * 3.7 * t).sin() * 0.3;
    let partial4 = (2.0 * std::f32::consts::PI * freq * 5.1 * t).sin() * 0.2;

    // Medium-fast decay
    let envelope = (-t * 4.0).exp();

    (fundamental + partial2 + partial3 + partial4) * envelope * 0.3
}

/// Ride tip - Bell-less ride, stick tip sound
pub(super) fn ride_tip_sample(sample_index: usize, sample_rate: f32) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = 0.6;

    if t > duration {
        return 0.0;
    }

    let envelope = (-t * 3.5).exp();

    // Less inharmonic than full ride, more focused pitch
    let fundamental = 950.0;
    let partial1 = (2.0 * std::f32::consts::PI * fundamental * t).sin();
    let partial2 = (2.0 * std::f32::consts::PI * fundamental * 2.2 * t).sin() * 0.4;
    let partial3 = (2.0 * std::f32::consts::PI * fundamental * 3.8 * t).sin() * 0.25;

    // Less noise than full ride
    let noise_val = noise(t * 4000.0) * 0.2;

    (partial1 + partial2 + partial3 + noise_val) * envelope * 0.5
}

/// Generate a china cymbal sample (trashy, explosive sound)
pub(super) fn china_sample(sample_index: usize, sample_rate: f32) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = 1.2;

    if t > duration {
        return 0.0;
    }

    let noise_val = noise(sample_index as f32);

    // Inharmonic frequencies for trashy sound
    let freq1 = (2.0 * std::f32::consts::PI * 6500.0 * t).sin();
    let freq2 = (2.0 * std::f32::consts::PI * 9500.0 * t).sin();
    let freq3 = (2.0 * std::f32::consts::PI * 11000.0 * t).sin();

    // Fast initial decay, then sustained
    let envelope = (-t * 3.5).exp();

    (noise_val * 0.6 + freq1 * 0.15 + freq2 * 0.15 + freq3 * 0.1) * envelope * 0.4
}

/// Generate a splash cymbal sample (short, bright accent)
pub(super) fn splash_sample(sample_index: usize, sample_rate: f32) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = 0.4;

    if t > duration {
        return 0.0;
    }

    let noise_val = noise(sample_index as f32);

    // Very bright frequencies
    let bright1 = (2.0 * std::f32::consts::PI * 8500.0 * t).sin();
    let bright2 = (2.0 * std::f32::consts::PI * 10000.0 * t).sin();

    // Quick decay
    let envelope = (-t * 6.0).exp();

    (noise_val * 0.7 + bright1 * 0.15 + bright2 * 0.15) * envelope * 0.35
}

/// Reverse cymbal - Reversed crash buildup
pub(super) fn reverse_cymbal_sample(sample_index: usize, sample_rate: f32) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = 1.5;

    if t > duration {
        return 0.0;
    }

    // Reverse envelope - builds up instead of decaying
    let envelope = (t / duration).powf(2.0);

    // Cymbal-like inharmonic partials
    let freq1 = (2.0 * std::f32::consts::PI * 450.0 * t).sin();
    let freq2 = (2.0 * std::f32::consts::PI * 680.0 * t).sin();
    let freq3 = (2.0 * std::f32::consts::PI * 1020.0 * t).sin();

    let noise_val = noise(t * 4500.0) * 0.6;
    let tonal = (freq1 + freq2 + freq3) * 0.15;

    (noise_val + tonal) * envelope * 0.5
}

/// Cymbal swell - Building cymbal wash
pub(super) fn cymbal_swell_sample(sample_index: usize, sample_rate: f32) -> f32 {
    let t = sample_index as f32 / sample_rate;
    let duration = 2.0;

    if t > duration {
        return 0.0;
    }

    // Gradual buildup then quick fade
    let envelope = if t < 1.5 {
        (t / 1.5).powf(2.0)
    } else {
        1.0 - ((t - 1.5) / 0.5).powf(2.0)
    };

    // Cymbal-like inharmonic partials
    let freq1 = (2.0 * std::f32::consts::PI * 520.0 * t).sin();
    let freq2 = (2.0 * std::f32::consts::PI * 780.0 * t).sin();
    let freq3 = (2.0 * std::f32::consts::PI * 1150.0 * t).sin();

    let noise_val = noise(t * 5000.0) * 0.6;
    let tonal = (freq1 + freq2 + freq3) * 0.15;

    (noise_val + tonal) * envelope * 0.5
}