commit ee49c0794bd4e55a9126b9f1c9ada6c5ebe94044
Author: Jay Robson <jsrobson10@gmail.com>
Date:   Sun Aug 18 00:16:53 2024 +1000

    initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..b0347e7
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+
+/midi-parser
+
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..43708e2
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "midifile"]
+	path = midifile
+	url = ./midifile
diff --git a/build.sh b/build.sh
new file mode 100755
index 0000000..7bab46c
--- /dev/null
+++ b/build.sh
@@ -0,0 +1,6 @@
+#!/bin/sh
+
+cd midifile && cmake . && make && cd ..
+
+g++ src/main.cpp ./midifile/libmidifile.a -o midi-parser -g -O3
+
diff --git a/midifile b/midifile
new file mode 160000
index 0000000..f79e8ea
--- /dev/null
+++ b/midifile
@@ -0,0 +1 @@
+Subproject commit f79e8ea395b858ceb6e0d8f353885ff80773dc76
diff --git a/src/main.cpp b/src/main.cpp
new file mode 100644
index 0000000..148b4ab
--- /dev/null
+++ b/src/main.cpp
@@ -0,0 +1,177 @@
+
+#include "../midifile/include/MidiFile.h"
+#include <cmath>
+#include <csignal>
+#include <cstring>
+#include <fstream>
+#include <iterator>
+#include <ostream>
+#include <thread>
+#include <iostream>
+#include <chrono>
+#include <vector>
+#include <fcntl.h>
+#include <termios.h> 
+
+const double KEYS[] = {16.35, 17.32, 18.35, 19.45, 20.6, 21.83, 23.12, 24.5, 25.96, 27.5, 29.14, 30.87};
+
+double get_key_freq(int key) {
+	int octave = key / std::size(KEYS);
+	return KEYS[key % std::size(KEYS)] * std::pow(2, octave);
+}
+
+volatile std::sig_atomic_t running = true;
+
+void signal_handler(int id) {
+	std::cout << "Quitting\n";
+	running = false;
+}
+
+int main(int argc, char** argv) {
+
+	std::signal(SIGINT, signal_handler);
+
+	smf::MidiFile midifile;
+	midifile.read(argv[2]);
+
+	int key_num_max = 0;
+
+	for(int i = 0; i < midifile.getNumTracks(); i++) {
+		for(int j = 0; j < midifile[i].size(); j++) {
+			auto& event = midifile[i][j];
+			if(event.isNote()) {
+				key_num_max = std::max(key_num_max, event.getKeyNumber());
+			}
+		}
+	}
+	
+	std::vector<int> key_channel_ids(key_num_max + 1);
+
+	for(int i = 0; i < key_channel_ids.size(); i++) {
+		key_channel_ids[i] = -1;
+	}
+
+	midifile.doTimeAnalysis();
+	midifile.joinTracks();
+
+	std::ofstream device {argv[1], std::ios::binary};
+	device << ":c,";
+	device.flush();
+	
+	auto& track = midifile[0];
+	int current_pressed_keys = 0;
+	int max_pressed_keys = 0;
+	double time_end = 0;
+
+	for(int i = 0; i < track.size() && running; i++) {
+		smf::MidiEvent& event = track[i];
+
+		if(!event.isNote()) {
+			continue;
+		}
+		
+		int key = event.getKeyNumber();
+		time_end = std::max(time_end, event.seconds);
+
+		if(event.isNoteOn()) {
+			if(key_channel_ids[key] == -1) {
+				key_channel_ids[key] = -2;
+				current_pressed_keys++;
+				if(current_pressed_keys > max_pressed_keys) {
+					max_pressed_keys = current_pressed_keys;
+				}
+			}
+		} else {
+			if(key_channel_ids[key] == -2) {
+				key_channel_ids[key] = -1;
+				current_pressed_keys--;
+			}
+		}
+	}
+	
+	double amplitude = 1.0 / max_pressed_keys;
+	std::vector<int> channel_key_nums(max_pressed_keys, -1);
+	auto now = std::chrono::high_resolution_clock::now();
+
+	for(int i = 0; i < track.size() && running; i++) {
+		smf::MidiEvent& event = track[i];
+
+		if(!event.isNote()) {
+			continue;
+		}
+		
+		int channel;
+		int key = event.getKeyNumber();
+
+		if(key < 0) {
+			std::cerr << "Warning: Bad Key (" << key << ")" << std::endl;
+			continue;
+		}
+
+		if(event.isNoteOn()) {
+			if(key_channel_ids[key] >= 0) {
+				continue;
+			}
+			for(int i = 0; i < channel_key_nums.size(); i++) {
+				if(channel_key_nums[i] < 0) {
+					channel_key_nums[i] = key;
+					key_channel_ids[key] = i;
+					channel = i;
+					goto end;
+				}
+			}
+			channel = channel_key_nums.size();
+			channel_key_nums.push_back(key);
+			key_channel_ids[key] = channel;
+		}
+		else {
+			channel = key_channel_ids[key];
+			if(channel == -1) {
+				continue;
+			}
+			key_channel_ids[key] = -1;
+			channel_key_nums[channel] = -1;
+		}
+end:
+
+		double key_freq = get_key_freq(key);
+
+		std::this_thread::sleep_until(now + std::chrono::duration<double>(event.seconds));
+		device << ":s," << channel << "," << key_freq << ',';
+
+		if(event.isNoteOn()) {
+			device << std::max(amplitude, 1.0/16.0);
+		} else {
+			device << '0';
+		}
+		device << ',';
+		device.flush();
+
+		for(int i = 0; i < key_channel_ids.size(); i++) {
+			if(key_channel_ids[i] < 0) {
+				std::cout << ' ';
+			} else {
+				std::cout << '|';
+			}
+		}
+
+		std::cout << " + ";
+
+		for(int i = 0; i < channel_key_nums.size(); i++) {
+			if(channel_key_nums[i] < 0) {
+				std::cout << ' ';
+			} else {
+				std::cout << '.';
+			}
+		}
+
+		std::cout << " + " << event.seconds << "s / " << time_end << "s" << std::endl;
+	}
+
+	device << ":c,";
+	device.flush();
+
+	return 0;
+}
+
+