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| 1 | +use cpal::traits::{DeviceTrait, HostTrait, StreamTrait}; |
| 2 | +use libpd_rs::{ |
| 3 | + functions::{receive::on_float, send::send_list_to, util::calculate_ticks}, |
| 4 | + Pd, |
| 5 | +}; |
| 6 | +use sys_info::loadavg; |
| 7 | + |
| 8 | +fn main() -> Result<(), Box<dyn std::error::Error>> { |
| 9 | + // Initialize cpal |
| 10 | + // This could have been another cross platform audio library |
| 11 | + // basically anything which gets you the audio callback of the os. |
| 12 | + let host = cpal::default_host(); |
| 13 | + |
| 14 | + // Currently we're only going to output to the default device |
| 15 | + let device = host.default_output_device().unwrap(); |
| 16 | + |
| 17 | + // Using the default config |
| 18 | + let config = device.default_output_config()?; |
| 19 | + |
| 20 | + // Let's get the default configuration from the audio driver. |
| 21 | + let sample_rate = config.sample_rate().0 as i32; |
| 22 | + let output_channels = config.channels() as i32; |
| 23 | + |
| 24 | + // Initialize libpd with that configuration, |
| 25 | + // with no input channels since we're not going to use them. |
| 26 | + let mut pd = Pd::init_and_configure(0, output_channels, sample_rate)?; |
| 27 | + let ctx = pd.audio_context(); |
| 28 | + |
| 29 | + // Let's evaluate another pd patch. |
| 30 | + // We could have opened a `.pd` file also. |
| 31 | + pd.eval_patch( |
| 32 | + r#" |
| 33 | + #N canvas 832 310 625 448 12; |
| 34 | + #X obj 18 27 r cpu_load; |
| 35 | + #X obj 55 394 s response; |
| 36 | + #X obj 13 261 *~; |
| 37 | + #X obj 112 240 vline~; |
| 38 | + #X obj 118 62 bng 15 250 50 0 empty empty empty 17 7 0 10 -262144 -1 |
| 39 | + -1; |
| 40 | + #X obj 14 395 dac~; |
| 41 | + #X obj 50 299 sig~; |
| 42 | + #X floatatom 50 268 5 0 0 0 - - -; |
| 43 | + #X obj 13 228 phasor~ 120; |
| 44 | + #X obj 139 61 metro 2000; |
| 45 | + #X obj 139 38 tgl 15 0 empty empty empty 17 7 0 10 -262144 -1 -1 1 |
| 46 | + 1; |
| 47 | + #X obj 18 52 unpack f f; |
| 48 | + #X obj 14 362 *~ 2; |
| 49 | + #X obj 14 336 vcf~ 12; |
| 50 | + #X obj 139 12 loadbang; |
| 51 | + #X msg 118 86 1 8 \, 0 0 10; |
| 52 | + #X obj 149 197 expr (480 + 80) * ($f1 - 8) / (4 - 16) + 480; |
| 53 | + #X obj 29 128 * 20; |
| 54 | + #X obj 167 273 expr (520 + 120) * ($f1 - 5) / (12 - 5) + 120; |
| 55 | + #X connect 0 0 11 0; |
| 56 | + #X connect 2 0 13 0; |
| 57 | + #X connect 3 0 2 1; |
| 58 | + #X connect 4 0 15 0; |
| 59 | + #X connect 6 0 13 1; |
| 60 | + #X connect 7 0 6 0; |
| 61 | + #X connect 8 0 2 0; |
| 62 | + #X connect 9 0 15 0; |
| 63 | + #X connect 10 0 9 0; |
| 64 | + #X connect 11 0 16 0; |
| 65 | + #X connect 11 0 18 0; |
| 66 | + #X connect 11 1 17 0; |
| 67 | + #X connect 12 0 5 0; |
| 68 | + #X connect 12 0 5 1; |
| 69 | + #X connect 13 0 12 0; |
| 70 | + #X connect 14 0 10 0; |
| 71 | + #X connect 15 0 3 0; |
| 72 | + #X connect 16 0 9 1; |
| 73 | + #X connect 17 0 1 0; |
| 74 | + #X connect 17 0 13 2; |
| 75 | + #X connect 18 0 7 0; |
| 76 | + "#, |
| 77 | + )?; |
| 78 | + |
| 79 | + // Here we are registering a listener (hook in libpd lingo) for |
| 80 | + // float values which are received from the pd patch. |
| 81 | + on_float(|source, value| { |
| 82 | + if source == "response" { |
| 83 | + print!("\r"); |
| 84 | + print!("Pd says that the q value of the vcf~ is: {value}"); |
| 85 | + } |
| 86 | + }); |
| 87 | + |
| 88 | + // Pd can send data to many different endpoints at a time. |
| 89 | + // This is why we need to declare our subscription to one or more first. |
| 90 | + // In this case we're subscribing to one, but it could have been many, |
| 91 | + pd.subscribe_to("response")?; |
| 92 | + |
| 93 | + // Build the audio stream. |
| 94 | + let output_stream = device.build_output_stream( |
| 95 | + &config.into(), |
| 96 | + move |data: &mut [f32], _: &cpal::OutputCallbackInfo| { |
| 97 | + // Provide the ticks to advance per iteration for the internal scheduler. |
| 98 | + let ticks = calculate_ticks(output_channels, data.len() as i32); |
| 99 | + |
| 100 | + // Here if we had an input buffer |
| 101 | + // we could have modified it to do pre-processing. |
| 102 | + |
| 103 | + // To receive messages from the pd patch we need to read the ring buffers |
| 104 | + // filled by the pd patch repeatedly to check if there are messages there. |
| 105 | + // Audio callback is a nice place to do that. |
| 106 | + ctx.receive_messages_from_pd(); |
| 107 | + |
| 108 | + // Process audio, advance internal scheduler. |
| 109 | + ctx.process_float(ticks, &[], data); |
| 110 | + |
| 111 | + // Here we could have done post processing after |
| 112 | + // pd processed our output buffer in place. |
| 113 | + }, |
| 114 | + |err| eprintln!("an error occurred on stream: {}", err), |
| 115 | + None, |
| 116 | + )?; |
| 117 | + |
| 118 | + // Turn audio processing on |
| 119 | + pd.activate_audio(true)?; |
| 120 | + |
| 121 | + // Run the stream |
| 122 | + output_stream.play()?; |
| 123 | + |
| 124 | + // This program does not terminate. |
| 125 | + // You would need to explicitly quit it. |
| 126 | + loop { |
| 127 | + // We sample in 2 hz. |
| 128 | + std::thread::sleep(std::time::Duration::from_millis(500)); |
| 129 | + |
| 130 | + // Read the average load of the cpu. |
| 131 | + let load = loadavg()?; |
| 132 | + |
| 133 | + let one_minute_cpu_load_average = load.one; |
| 134 | + let five_minutes_cpu_load_average = load.five; |
| 135 | + |
| 136 | + // Lists are one of the types we can send to pd. |
| 137 | + // Although pd allows for heterogeneous lists, |
| 138 | + // even if we're not using them heterogeneously in this example, |
| 139 | + // we still need to send it as a list of Atoms. |
| 140 | + |
| 141 | + // Atom is an encapsulating type in pd to unify |
| 142 | + // various types of data together under the same umbrella. |
| 143 | + // Check out `libpd_rs::types` module for more details. |
| 144 | + |
| 145 | + // Atoms have From trait implemented for them for |
| 146 | + // floats and strings. |
| 147 | + send_list_to( |
| 148 | + "cpu_load", |
| 149 | + &[ |
| 150 | + one_minute_cpu_load_average.into(), |
| 151 | + five_minutes_cpu_load_average.into(), |
| 152 | + ], |
| 153 | + )?; |
| 154 | + } |
| 155 | +} |
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