Initial commit

Add files with test program.

.gitattributes

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+# This makes the repo play nice with git on Windows
+* text=auto

.gitignore

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+cmake-build-debug
+*.o
+CMakeFiles/
+CMakeCache.txt
+Makefile
+cmake_install.cmake
+example
+.idea/

CMakeLists.txt

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+cmake_minimum_required(VERSION 3.24)
+project(midi_note_id_utils C)
+
+set(CMAKE_C_STANDARD 11)
+
+include_directories(.)
+
+add_executable(test-note-names
+        test-note-names.c
+        midi-utils.c
+        midi-utils.h)
+
+
+add_custom_command(
+    TARGET test-note-names POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E copy
+        "${CMAKE_HOME_DIRECTORY}/cases.txt"
+        $<TARGET_FILE_DIR:test-note-names>
+)

cases.txt

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+C0 0
+C#0 1
+D0 2
+D#0 3
+E0 4
+F0 5
+F#0 6
+G0 7
+G#0 8
+A0 9
+A#0 10
+B0 11
+C1 12
+C2 24
+C3 36
+C4 48
+C5 60
+A5 69
+C6 72
+C7 84
+C8 96
+C9 108
+C10 120
+G10 127
+C11 132
+C12 144
+C13 156
+C14 168
+C15 180
+C16 192
+C17 204
+C18 216
+C19 228
+C20 240
+C21 252
+D#21 255

midi-utils.c

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+#include "midi-utils.h"
+
+char* MIDI_GetNoteName(unsigned char midi_note) {
+	static const char* pitch_names[] = {
+		"C",
+		"C#",
+		"D",
+		"D#",
+		"E",
+		"F",
+		"F#",
+		"G",
+		"G#",
+		"A",
+		"A#",
+		"B"
+	};
+
+	const unsigned char pitch_class = midi_note % 12;
+	const unsigned char octave = midi_note / 12;
+	static char note_name[8];
+	sprintf(note_name, "%s%u", pitch_names[pitch_class], octave);
+	return note_name;
+}
+
+unsigned char MIDI_GetNoteFromName(const char* name) {
+	char name_copy[8];
+	strcpy(name_copy, name);
+	_strlwr(name_copy);
+
+	unsigned char octave = 0;
+	unsigned char has_accidental = name_copy[1] == '#' || name_copy[1] == 'b';
+	unsigned char octave_start = has_accidental ? 2 : 1;
+	unsigned char pitch_class;
+	char octave_offset = 0;
+
+	for (unsigned char i = octave_start; '0' <= name_copy[i] && name_copy[i] <= '9'; i += 1) {
+		octave *= 10;
+		octave += name_copy[i] - '0';
+	}
+
+	if (strstr(name_copy, "c#") || strstr(name_copy, "db")) {
+		pitch_class = 1;
+	} else if (strstr(name_copy, "d#") || strstr(name_copy, "eb")) {
+		pitch_class = 3;
+	} else if (strstr(name_copy, "fb")) {
+		pitch_class = 4;
+	} else if (strstr(name_copy, "e#")) {
+		pitch_class = 5;
+	} else if (strstr(name_copy, "f#") || strstr(name_copy, "gb")) {
+		pitch_class = 6;
+	} else if (strstr(name_copy, "g#") || strstr(name_copy, "ab")) {
+		pitch_class = 8;
+	} else if (strstr(name_copy, "a#") || strstr(name_copy, "bb")) {
+		pitch_class = 10;
+	} else if (strstr(name_copy, "cb")) {
+		pitch_class = 11;
+		octave_offset = -1;
+	} else if (strstr(name_copy, "b#")) {
+		pitch_class = 0;
+		octave_offset = 1;
+	} else if (strstr(name_copy, "c")) {
+		pitch_class = 0;
+	} else if (strstr(name_copy, "d")) {
+		pitch_class = 2;
+	} else if (strstr(name_copy, "e")) {
+		pitch_class = 4;
+	} else if (strstr(name_copy, "f")) {
+		pitch_class = 5;
+	} else if (strstr(name_copy, "g")) {
+		pitch_class = 7;
+	} else if (strstr(name_copy, "a")) {
+		pitch_class = 9;
+	} else if (strstr(name_copy, "b")) {
+		pitch_class = 11;
+	} else {
+		return 255u;
+	}
+
+	return ((octave * 12) + octave_offset) + pitch_class;
+}

midi-utils.h

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+#ifndef MIDI_UTILS_H
+#define MIDI_UTILS_H
+
+#include <stdio.h>
+#include <string.h>
+
+#define MIDI_MESSAGE_NOTEON 0x90u
+#define MIDI_MESSAGE_NOTEOFF 0x80u
+
+#define MIDI_CC_SUSTAIN 0x40u
+#define MIDI_CC_SOSTENUTO 0x42u
+#define MIDI_CC_UNACORDA 0x43u
+
+char* MIDI_GetNoteName(unsigned char);
+
+unsigned char MIDI_GetNoteFromName(const char*);
+
+#endif

test-note-names.c

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+#include <stdio.h>
+#include <assert.h>
+#include "midi-utils.h"
+
+int main(void) {
+	FILE* f = fopen("cases.txt", "r");
+	if (!f) {
+		return -1;
+	}
+	char read_note_name[255] = "";
+	unsigned int read_note_value;
+	while (!feof(f)) {
+		fscanf(f, "%s %d\n", read_note_name, &read_note_value);
+		unsigned int actual_note_value = MIDI_GetNoteFromName(read_note_name);
+		printf("MIDI_GetNoteFromName(\"%s\")...", read_note_name);
+		assert(read_note_value == actual_note_value);
+		printf("OK!\n");
+
+		printf("MIDI_GetNoteName(%d)...", read_note_value);
+		assert(!strcmp(MIDI_GetNoteName(read_note_value), read_note_name));
+		printf("OK!\n");
+	}
+
+	fclose(f);
+	return 0;
+}