1 files changed, 128 insertions, 0 deletions
diff --git a/plugins/eg-midiamp.lv2/midiamp.cpp b/plugins/eg-midiamp.lv2/midiamp.cpp
new file mode 100644
index 0000000..2fff4e7
--- /dev/null
+++ b/plugins/eg-midiamp.lv2/midiamp.cpp
@@ -0,0 +1,128 @@
+/*
+  Copyright 2015 David Robillard <d@drobilla.net>
+
+  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.
+
+  THIS 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 <math.h>
+#include <stdlib.h>
+
+#include "lv2/lv2plug.in/ns/ext/atom/atom.hpp"
+#include "lv2/lv2plug.in/ns/ext/midi/midi.h"
+#include "lv2/lv2plug.in/ns/ext/urid/urid.hpp"
+#include "lv2/lv2plug.in/ns/lv2core/Lib.hpp"
+#include "lv2/lv2plug.in/ns/lv2core/Plugin.hpp"
+
+/** MIDI-controlled amplifier. */
+class MidiAmp : public lv2::Plugin<MidiAmp> {
+public:
+	MidiAmp(double                    rate,
+	        const char*               bundle_path,
+	        const LV2_Feature* const* features,
+	        bool*                     valid)
+		: Plugin(rate, bundle_path, features, valid)
+		, m_map(features, valid)
+		, m_vol(1.0f)
+	{
+		if (!*valid) {
+			return;
+		}
+
+		midi_MidiEvent = m_map(LV2_MIDI__MidiEvent);
+	}
+
+	typedef enum {
+		AMP_CONTROL = 0,
+		AMP_INPUT   = 1,
+		AMP_OUTPUT  = 2
+	} PortIndex;
+
+	void connect_port(uint32_t port, void* data) {
+		switch ((PortIndex)port) {
+		case AMP_CONTROL:
+			m_ports.control = (const lv2::atom::Sequence*)data;
+			break;
+		case AMP_INPUT:
+			m_ports.input = (const float*)data;
+			break;
+		case AMP_OUTPUT:
+			m_ports.output = (float*)data;
+			break;
+		}
+	}
+
+	void run(const uint32_t n_samples) {
+		uint32_t offset = 0;
+		for (const lv2::atom::Event& ev : *m_ports.control) {
+			// Emit audio up to this event's time
+			for (uint32_t o = offset; o < ev.time.frames; ++o) {
+				m_ports.output[o] = m_ports.input[0] * m_vol;
+			}
+
+			// Process event
+			if (ev.type() == midi_MidiEvent) {
+				const uint8_t* const msg = (const uint8_t*)(&ev + 1);
+				if (lv2_midi_message_type(msg) == LV2_MIDI_MSG_CONTROLLER &&
+				    msg[1] == LV2_MIDI_CTL_MSB_MAIN_VOLUME) {
+					m_vol = msg[2] / 127.0f;
+				}
+			}
+
+			offset = ev.time.frames;
+		}
+
+		// Emit remaining audio to the end of the block
+		for (uint32_t o = offset; o < n_samples; ++o) {
+			m_ports.output[o] = m_ports.input[0] * m_vol;
+		}
+	}
+
+private:
+	typedef struct {
+		const lv2::atom::Sequence* control;
+		const float*               input;
+		float*                     output;
+	} Ports;
+
+	lv2::urid::Map<true> m_map;
+	lv2::urid::URID      midi_MidiEvent;
+	Ports                m_ports;
+	float                m_vol;
+};
+
+/** Plugin library. */
+class MidiAmpLib : public lv2::Lib<MidiAmpLib>
+{
+public:
+	MidiAmpLib(const char*              bundle_path,
+	           const LV2_Feature*const* features)
+		: lv2::Lib<MidiAmpLib>(bundle_path, features)
+		, m_amp(MidiAmp::descriptor("http://lv2plug.in/plugins/eg-midiamp"))
+	{}
+
+	const LV2_Descriptor* get_plugin(uint32_t index) {
+		return index == 0 ? &m_amp : NULL;
+	}
+
+private:
+	LV2_Descriptor m_amp;
+};
+
+/** Library entry point. */
+LV2_SYMBOL_EXPORT const LV2_Lib_Descriptor*
+lv2_lib_descriptor(const char*                bundle_path,
+                   const LV2_Feature *const * features)
+
+{
+	return new MidiAmpLib(bundle_path, features);
+}