diff --git a/plugins/buffr_glitch/src/buffer.rs b/plugins/buffr_glitch/src/buffer.rs
new file mode 100644
index 00000000..65455fbe
--- /dev/null
+++ b/plugins/buffr_glitch/src/buffer.rs
@@ -0,0 +1,54 @@
+// Buffr Glitch: a MIDI-controlled buffer repeater
+// Copyright (C) 2022 Robbert van der Helm
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see .
+
+use nih_plug::prelude::util;
+
+/// A super simple ring buffer abstraction to store the last received audio. This needs to be able
+/// to store at least the number of samples that correspond to the period size of MIDI note 0.
+#[derive(Debug, Default)]
+pub struct RingBuffer {
+ /// Sample buffers indexed by channel and sample index.
+ buffers: Vec>,
+ /// The positions within the sample buffers the next sample should be written to. Since all
+ /// channels will be written to in lockstep we only need a single value here. It's incremented
+ /// when writing a sample for the last channel.
+ next_write_pos: usize,
+}
+
+impl RingBuffer {
+ /// Initialize or resize the buffers to fit a certain number of channels and samples. The inner
+ /// buffer capacity is determined by the number of samples it takes to represent the period of
+ /// MIDI note 0 at the specified sample rate, rounded up to a power of two. Make sure to call
+ /// [`reset()`][Self::reset()] after this.
+ pub fn resize(&mut self, num_channels: usize, sample_rate: f32) {
+ let note_frequency = util::midi_note_to_freq(0);
+ let note_period_samples = (note_frequency.recip() * sample_rate).ceil() as usize;
+ let buffer_len = note_period_samples.next_power_of_two();
+
+ self.buffers.resize_with(num_channels, Vec::new);
+ for buffer in self.buffers.iter_mut() {
+ buffer.resize(buffer_len, 0.0);
+ }
+ }
+
+ /// Zero out the buffers.
+ pub fn reset(&mut self) {
+ for buffer in self.buffers.iter_mut() {
+ buffer.fill(0.0);
+ }
+ self.next_write_pos = 0;
+ }
+}
diff --git a/plugins/buffr_glitch/src/lib.rs b/plugins/buffr_glitch/src/lib.rs
index c083239f..9e151a4c 100644
--- a/plugins/buffr_glitch/src/lib.rs
+++ b/plugins/buffr_glitch/src/lib.rs
@@ -17,8 +17,15 @@
use nih_plug::prelude::*;
use std::sync::Arc;
+mod buffer;
+
struct BuffrGlitch {
params: Arc,
+
+ sample_rate: f32,
+ /// The ring buffer we'll write samples to. When a key is held down, we'll stop writing samples
+ /// and instead keep reading from this buffer until the key is released.
+ buffer: buffer::RingBuffer,
}
#[derive(Params)]
@@ -28,6 +35,9 @@ impl Default for BuffrGlitch {
fn default() -> Self {
Self {
params: Arc::new(BuffrGlitchParams::default()),
+
+ sample_rate: 1.0,
+ buffer: buffer::RingBuffer::default(),
}
}
}
@@ -59,6 +69,25 @@ impl Plugin for BuffrGlitch {
config.num_input_channels == config.num_output_channels && config.num_input_channels > 0
}
+ fn initialize(
+ &mut self,
+ bus_config: &BusConfig,
+ buffer_config: &BufferConfig,
+ _context: &mut impl InitContext,
+ ) -> bool {
+ self.sample_rate = buffer_config.sample_rate;
+ self.buffer.resize(
+ bus_config.num_input_channels as usize,
+ buffer_config.sample_rate,
+ );
+
+ true
+ }
+
+ fn reset(&mut self) {
+ self.buffer.reset();
+ }
+
fn process(
&mut self,
_buffer: &mut Buffer,