Add documentation

Document the exported functions and constants.

midi-utils.c

@@ -1,6 +1,10 @@
 #include "midi-utils.h"
 
 #if !defined _WIN32
+/**
+ * Converts a string to lowercase.
+ * @param dest - The string to convert.
+ */
 void _strlwr(char* dest) {
 	for (unsigned int i = 0; i < strlen(dest); i += 1) {
 		if ('A' <= dest[i] && dest[i] <= 'Z') {
@@ -10,6 +14,13 @@ void _strlwr(char* dest) {
 }
 #endif
 
+/**
+ * Gets the name of a MIDI note value.
+ * @param midi_note - The MIDI note value.
+ * @note Valid values are from 0-127.
+ * @return The MIDI note name.
+ * @see MIDI_GetNoteFromName()
+ */
 char* MIDI_GetNoteName(unsigned char midi_note) {
 	static const char* pitch_names[] = {
 		"C",
@@ -33,7 +44,17 @@ char* MIDI_GetNoteName(unsigned char midi_note) {
 	return note_name;
 }
 
+/**
+ * Gets the note value from a MIDI note name
+ * @param name - The MIDI note name.
+ * @return The MIDI note value, or 255 if an invalid name is passed.
+ * @see MIDI_GetNoteName()
+ */
 unsigned char MIDI_GetNoteFromName(const char* name) {
+	if (!name) {
+		return 255u;
+	}
+
 	char name_copy[8];
 	strcpy(name_copy, name);
 	_strlwr(name_copy);

midi-utils.h

@@ -4,20 +4,48 @@
 #include <stdio.h>
 #include <string.h>
 
+/**
+ * MIDI message type for note on.
+ */
 #define MIDI_MESSAGE_NOTEON 0x90u
+
+/**
+ * MIDI message type for note off.
+ */
 #define MIDI_MESSAGE_NOTEOFF 0x80u
 
+/**
+ * Continuous control number for sustain, or damper (right pedal).
+ */
 #define MIDI_CC_SUSTAIN 0x40u
+
+/**
+ * Continuous control number for sostenuto (center pedal).
+ */
 #define MIDI_CC_SOSTENUTO 0x42u
+
+/**
+ * Continuous control number for una corda (left pedal).
+ */
 #define MIDI_CC_UNACORDA 0x43u
 
 #if defined __cplusplus
 extern "C" {
 #endif
 
-char *MIDI_GetNoteName(unsigned char);
-
-unsigned char MIDI_GetNoteFromName(const char *);
+/**
+ * Gets the name of a MIDI note value.
+ * @return The MIDI note name.
+ * @see MIDI_GetNoteFromName()
+ */
+char* MIDI_GetNoteName(unsigned char);
+
+/**
+ * Gets the note value from a MIDI note name
+ * @return The MIDI note value.
+ * @see MIDI_GetNoteName()
+ */
+unsigned char MIDI_GetNoteFromName(const char*);
 
 #if defined __cplusplus
 }