commit 30710967d15f43778b0391a9151e2cb67f7edc31
parent 0d962da768dd40485b5a24c322e469ae32fc0c79
Author: falkTX <falktx@falktx.com>
Date: Thu, 27 May 2021 11:39:32 +0100
Add Metronome example
Signed-off-by: falkTX <falktx@falktx.com>
Diffstat:
6 files changed, 472 insertions(+), 0 deletions(-)
diff --git a/Makefile b/Makefile
@@ -24,6 +24,7 @@ examples: dgl
$(MAKE) all -C examples/Info
$(MAKE) all -C examples/Latency
$(MAKE) all -C examples/Meters
+ $(MAKE) all -C examples/Metronome
$(MAKE) all -C examples/MidiThrough
$(MAKE) all -C examples/Parameters
$(MAKE) all -C examples/SendNote
@@ -66,6 +67,7 @@ clean:
$(MAKE) clean -C examples/Info
$(MAKE) clean -C examples/Latency
$(MAKE) clean -C examples/Meters
+ $(MAKE) clean -C examples/Metronome
$(MAKE) clean -C examples/MidiThrough
$(MAKE) clean -C examples/Parameters
$(MAKE) clean -C examples/SendNote
diff --git a/examples/CVPort/ExamplePluginCVPort.cpp b/examples/CVPort/ExamplePluginCVPort.cpp
@@ -1,6 +1,7 @@
/*
* DISTRHO Plugin Framework (DPF)
* Copyright (C) 2012-2021 Filipe Coelho <falktx@falktx.com>
+ * Copyright (C) 2020 Takamitsu Endo
*
* Permission to use, copy, modify, and/or distribute this software for any purpose with
* or without fee is hereby granted, provided that the above copyright notice and this
diff --git a/examples/Metronome/DistrhoPluginInfo.h b/examples/Metronome/DistrhoPluginInfo.h
@@ -0,0 +1,29 @@
+/*
+ * DISTRHO Plugin Framework (DPF)
+ * Copyright (C) 2012-2021 Filipe Coelho <falktx@falktx.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any purpose with
+ * or without fee is hereby granted, provided that the above copyright notice and this
+ * permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
+ * TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef DISTRHO_PLUGIN_INFO_H_INCLUDED
+#define DISTRHO_PLUGIN_INFO_H_INCLUDED
+
+#define DISTRHO_PLUGIN_BRAND "DISTRHO"
+#define DISTRHO_PLUGIN_NAME "Metronome"
+#define DISTRHO_PLUGIN_URI "http://distrho.sf.net/examples/Metronome"
+
+#define DISTRHO_PLUGIN_IS_RT_SAFE 1
+#define DISTRHO_PLUGIN_NUM_INPUTS 0
+#define DISTRHO_PLUGIN_NUM_OUTPUTS 1
+#define DISTRHO_PLUGIN_WANT_TIMEPOS 1
+
+#endif // DISTRHO_PLUGIN_INFO_H_INCLUDED
diff --git a/examples/Metronome/ExamplePluginMetronome.cpp b/examples/Metronome/ExamplePluginMetronome.cpp
@@ -0,0 +1,364 @@
+/*
+ * DISTRHO Plugin Framework (DPF)
+ * Copyright (C) 2012-2021 Filipe Coelho <falktx@falktx.com>
+ * Copyright (C) 2020 Takamitsu Endo
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any purpose with
+ * or without fee is hereby granted, provided that the above copyright notice and this
+ * permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
+ * TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "DistrhoPlugin.hpp"
+
+START_NAMESPACE_DISTRHO
+
+// -----------------------------------------------------------------------------------------------------------
+
+/**
+ 1-pole lowpass filter to smooth out parameters and envelopes.
+ This filter is guaranteed not to overshoot.
+ */
+class Smoother {
+ float kp;
+
+public:
+ float value;
+
+ Smoother()
+ : kp(0.0f),
+ value(0.0f) {}
+
+ /**
+ Set kp from cutoff frequency in Hz.
+ For derivation, see the answer of Matt L. on the url below. Equation 3 is used.
+
+ Computation is done on double for accuracy. When using float, kp will be inaccurate
+ if the cutoffHz is below around 3.0 to 4.0 Hz.
+
+ Reference:
+ - Single-pole IIR low-pass filter - which is the correct formula for the decay coefficient?
+ https://dsp.stackexchange.com/questions/54086/single-pole-iir-low-pass-filter-which-is-the-correct-formula-for-the-decay-coe
+ */
+ void setCutoff(float sampleRate, float cutoffHz) {
+ double omega_c = 2.0 * M_PI * cutoffHz / sampleRate;
+ double y = 1.0 - std::cos(omega_c);
+ kp = float(-y + std::sqrt((y + 2.0) * y));
+ }
+
+ float process(float input) {
+ return value += kp * (input - value);
+ }
+};
+
+// -----------------------------------------------------------------------------------------------------------
+
+/**
+ Plugin that demonstrates tempo sync in DPF.
+ The tempo sync implementation is on the first if branch in run() method.
+ */
+class ExamplePluginMetronome : public Plugin
+{
+public:
+ ExamplePluginMetronome()
+ : Plugin(4, 0, 0), // 4 parameters, 0 programs, 0 states
+ sampleRate(getSampleRate()),
+ counter(0),
+ phase(0.0f),
+ decay(0.0f),
+ gain(0.5f),
+ semitone(72),
+ cent(0),
+ decayTime(0.2f)
+ {
+ }
+
+protected:
+ /* --------------------------------------------------------------------------------------------------------
+ * Information */
+
+ /**
+ Get the plugin label.
+ A plugin label follows the same rules as Parameter::symbol, with the exception that it can start with numbers.
+ */
+ const char* getLabel() const override
+ {
+ return "Metronome";
+ }
+
+ /**
+ Get an extensive comment/description about the plugin.
+ */
+ const char* getDescription() const override
+ {
+ return "Simple metronome plugin which outputs impulse at the start of every beat.";
+ }
+
+ /**
+ Get the plugin author/maker.
+ */
+ const char* getMaker() const override
+ {
+ return "DISTRHO";
+ }
+
+ /**
+ Get the plugin homepage.
+ */
+ const char* getHomePage() const override
+ {
+ return "https://github.com/DISTRHO/DPF";
+ }
+
+ /**
+ Get the plugin license name (a single line of text).
+ For commercial plugins this should return some short copyright information.
+ */
+ const char* getLicense() const override
+ {
+ return "ISC";
+ }
+
+ /**
+ Get the plugin version, in hexadecimal.
+ */
+ uint32_t getVersion() const override
+ {
+ return d_version(1, 0, 0);
+ }
+
+ /**
+ Get the plugin unique Id.
+ This value is used by LADSPA, DSSI and VST plugin formats.
+ */
+ int64_t getUniqueId() const override
+ {
+ return d_cconst('d', 'M', 'e', 't');
+ }
+
+ /* --------------------------------------------------------------------------------------------------------
+ * Init */
+
+ /**
+ Initialize the parameter @a index.
+ This function will be called once, shortly after the plugin is created.
+ */
+ void initParameter(uint32_t index, Parameter& parameter) override
+ {
+ parameter.hints = kParameterIsAutomable;
+
+ switch (index)
+ {
+ case 0:
+ parameter.name = "Gain";
+ parameter.hints |= kParameterIsLogarithmic;
+ parameter.ranges.min = 0.0f;
+ parameter.ranges.max = 1.0f;
+ parameter.ranges.def = 0.5f;
+ break;
+ case 1:
+ parameter.name = "DecayTime";
+ parameter.hints |= kParameterIsLogarithmic;
+ parameter.ranges.min = 0.001f;
+ parameter.ranges.max = 1.0f;
+ parameter.ranges.def = 0.2f;
+ break;
+ case 2:
+ parameter.name = "Semitone";
+ parameter.hints |= kParameterIsInteger;
+ parameter.ranges.min = 0;
+ parameter.ranges.max = 127;
+ parameter.ranges.def = 72;
+ break;
+ case 3:
+ parameter.name = "Cent";
+ parameter.hints |= kParameterIsInteger;
+ parameter.ranges.min = -100;
+ parameter.ranges.max = 100;
+ parameter.ranges.def = 0;
+ break;
+ }
+
+ parameter.symbol = parameter.name;
+ }
+
+ /* --------------------------------------------------------------------------------------------------------
+ * Internal data */
+
+ /**
+ Get the current value of a parameter.
+ */
+ float getParameterValue(uint32_t index) const override
+ {
+ switch (index)
+ {
+ case 0:
+ return gain;
+ case 1:
+ return decayTime;
+ case 2:
+ return semitone;
+ case 3:
+ return cent;
+ }
+
+ return 0.0f;
+ }
+
+ /**
+ Change a parameter value.
+ */
+ void setParameterValue(uint32_t index, float value) override
+ {
+ switch (index)
+ {
+ case 0:
+ gain = value;
+ break;
+ case 1:
+ decayTime = value;
+ break;
+ case 2:
+ semitone = value;
+ break;
+ case 3:
+ cent = value;
+ break;
+ }
+ }
+
+ /* --------------------------------------------------------------------------------------------------------
+ * Process */
+
+ /**
+ Run/process function for plugins without MIDI input.
+ `inputs` is commented out because this plugin has no inputs.
+ */
+ void run(const float** /* inputs */, float** outputs, uint32_t frames) override
+ {
+ const TimePosition& timePos(getTimePosition());
+ float* const output = outputs[0];
+
+ if (timePos.playing && timePos.bbt.valid)
+ {
+ // Better to use double when manipulating time.
+ double secondsPerBeat = 60.0 / timePos.bbt.beatsPerMinute;
+ double framesPerBeat = sampleRate * secondsPerBeat;
+ double beatFraction = timePos.bbt.tick / timePos.bbt.ticksPerBeat;
+
+ // If beatFraction is zero, next beat is exactly at the start of currenct cycle.
+ // Otherwise, reset counter to the frames to the next beat.
+ counter = d_isZero(beatFraction)
+ ? 0
+ : static_cast<uint32_t>(framesPerBeat * (1.0 - beatFraction));
+
+ // Compute deltaPhase in normalized frequency.
+ // semitone is midi note number, which is A4 (440Hz at standard tuning) at 69.
+ // Frequency goes up to 1 octave higher at the start of bar.
+ float frequency = 440.0f * std::pow(2.0f, (100.0f * (semitone - 69.0f) + cent) / 1200.0f);
+ float deltaPhase = frequency / sampleRate;
+ float octave = timePos.bbt.beat == 1 ? 2.0f : 1.0f;
+
+ // Envelope reaches 1e-5 at decayTime after triggering.
+ decay = std::pow(1e-5, 1.0 / (decayTime * sampleRate));
+
+ // Reset phase and frequency at the start of transpose.
+ if (!wasPlaying)
+ {
+ phase = 0.0f;
+
+ deltaPhaseSmoother.value = deltaPhase;
+ gainSmoother.value = 1.0f;
+ envelopeSmoother.value = 0.0f;
+ }
+
+ for (uint32_t i = 0; i < frames; ++i)
+ {
+ if (counter <= 0)
+ {
+ envelope = 1.0f;
+ counter = static_cast<uint32_t>(framesPerBeat + 0.5);
+ octave = (!wasPlaying || timePos.bbt.beat == static_cast<int32_t>(timePos.bbt.beatsPerBar)) ? 2.0f
+ : 1.0f;
+ }
+ --counter;
+
+ envelope *= decay;
+
+ phase += octave * deltaPhaseSmoother.process(deltaPhase);
+ phase -= std::floor(phase);
+
+ output[i] = gainSmoother.process(gain)
+ * envelopeSmoother.process(envelope)
+ * std::sin(float(2.0 * M_PI) * phase);
+ }
+ }
+ else
+ {
+ // Stop metronome if not playing or timePos.bbt is invalid.
+ std::memset(output, 0, sizeof(float)*frames);
+ }
+
+ wasPlaying = timePos.playing;
+ }
+
+ /* --------------------------------------------------------------------------------------------------------
+ * Callbacks (optional) */
+
+ /**
+ Optional callback to inform the plugin about a sample rate change.
+ This function will only be called when the plugin is deactivated.
+ */
+ void sampleRateChanged(double newSampleRate) override
+ {
+ sampleRate = newSampleRate;
+
+ // Cutoff value was tuned manually.
+ deltaPhaseSmoother.setCutoff(sampleRate, 100.0f);
+ gainSmoother.setCutoff(sampleRate, 500.0f);
+ envelopeSmoother.setCutoff(sampleRate, 250.0f);
+ }
+
+ // -------------------------------------------------------------------------------------------------------
+
+private:
+ float sampleRate;
+ uint32_t counter; // Stores number of frames to the next beat.
+ bool wasPlaying; // Used to reset phase and frequency at the start of transpose.
+ float phase; // Sine wave phase. Normalized in [0, 1).
+ float envelope; // Current value of gain envelope.
+ float decay; // Coefficient to decay envelope in a frame.
+
+ Smoother deltaPhaseSmoother;
+ Smoother gainSmoother;
+ Smoother envelopeSmoother;
+
+ // Parameters.
+ float gain;
+ float semitone;
+ float cent;
+ float decayTime;
+
+ /**
+ Set our plugin class as non-copyable and add a leak detector just in case.
+ */
+ DISTRHO_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(ExamplePluginMetronome)
+};
+
+/* ------------------------------------------------------------------------------------------------------------
+ * Plugin entry point, called by DPF to create a new plugin instance. */
+
+Plugin* createPlugin()
+{
+ return new ExamplePluginMetronome();
+}
+
+// -----------------------------------------------------------------------------------------------------------
+
+END_NAMESPACE_DISTRHO
diff --git a/examples/Metronome/Makefile b/examples/Metronome/Makefile
@@ -0,0 +1,42 @@
+#!/usr/bin/make -f
+# Makefile for DISTRHO Plugins #
+# ---------------------------- #
+# Created by falkTX
+#
+
+# --------------------------------------------------------------
+# Project name, used for binaries
+
+NAME = d_metronome
+
+# --------------------------------------------------------------
+# Files to build
+
+FILES_DSP = \
+ ExamplePluginMetronome.cpp
+
+# --------------------------------------------------------------
+# Do some magic
+
+include ../../Makefile.plugins.mk
+
+# --------------------------------------------------------------
+# Enable all possible plugin types
+
+ifeq ($(HAVE_JACK),true)
+ifeq ($(HAVE_OPENGL),true)
+TARGETS += jack
+endif
+endif
+
+ifeq ($(HAVE_OPENGL),true)
+TARGETS += lv2_sep
+else
+TARGETS += lv2_dsp
+endif
+
+TARGETS += vst
+
+all: $(TARGETS)
+
+# --------------------------------------------------------------
diff --git a/examples/Metronome/README.md b/examples/Metronome/README.md
@@ -0,0 +1,34 @@
+# Metronome example
+
+This example will show tempo sync in DPF.<br/>
+
+This plugin will output sine wave at the start of every beat.<br/>
+The pitch of sine wave is 1 octave higher at the start of every bar.<br/>
+
+4 parameters are avaialble:
+
+- Gain
+- Decay time
+- Semitone
+- Cent
+
+To calculate frames to the next beat from the start of current audio buffer, following implementation is used.<br/>
+
+```c++
+const TimePosition& timePos(getTimePosition());
+
+if (timePos.bbt.valid) {
+ double secondsPerBeat = 60.0 / timePos.bbt.beatsPerMinute;
+ double framesPerBeat = sampleRate * secondsPerBeat;
+ double beatFraction = timePos.bbt.tick / timePos.bbt.ticksPerBeat;
+
+ uint32_t framesToNextBeat = beatFraction == 0.0
+ ? 0
+ : static_cast<uint32_t>(framesPerBeat * (1.0 - beatFraction));
+
+ // ...
+}
+```
+
+Reference:
+- [DISTRHO Plugin Framework: TimePosition::BarBeatTick Struct Reference](https://distrho.github.io/DPF/structTimePosition_1_1BarBeatTick.html)
