From 13056b602ac05a47bdf9e04a991da158f5f4d556 Mon Sep 17 00:00:00 2001
From: Thomas White <taw@bitwiz.org.uk>
Date: Sat, 12 Nov 2011 22:24:26 +0100
Subject: Read notes

---
 maestropond.c | 145 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 141 insertions(+), 4 deletions(-)

diff --git a/maestropond.c b/maestropond.c
index bfe3a44..3b9792f 100644
--- a/maestropond.c
+++ b/maestropond.c
@@ -70,11 +70,138 @@ out:
 }
 
 
+static void music_attribute(unsigned char ma)
+{
+	if ( (ma & 0x7f) == 0x40 ) {
+
+		printf("Warning: reserved gate type.\n");
+
+	} else if ( (ma & 0x3f) == 0x20 ) {
+
+		printf("Bar line\n");
+
+	} else if ( (ma & 0x1f) == 0x10 ) {
+
+		printf("Bar line\n");
+
+	} else if ( (ma & 0xf) == 0x8 ) {
+
+		printf("Octave shift\n");
+
+	} else if ( (ma & 0x7) == 0x4 ) {
+
+		int st;
+
+		st = 1 + ((ma & 0xc0) >> 6);
+		if ( ma & 0x10 ) {
+			printf("Slur on (stave %i)\n", st);
+		} else {
+			printf("Slur off (stave %i)\n", st);
+		}
+
+	} else if ( (ma & 0x3) == 0x2 ) {
+
+		int ct, st;
+
+		ct = (ma & 0x18) >> 3;
+		switch ( ct ) {
+
+			case 0 :
+			printf("Treble clef:");
+			break;
+
+			case 1 :
+			printf("Alto clef:");
+			break;
+
+			case 2 :
+			printf("Tenor clef:");
+			break;
+
+			case 3 :
+			printf("Bass clef:");
+			break;
+		}
+
+		st = (ma & 0x60) >> 5;
+		printf(" stave %i\n", st);
+
+	} else if ( (ma & 0x1) == 0x1 ) {
+
+		int tn, td;
+
+		tn = 1 + ((ma & 0x1e) >> 1);
+		td = 1 + ((ma & 0xe0) >> 5);
+		printf("Time signature %i/%i\n", tn, td);
+	}
+}
+
+
+
+static void get_note(unsigned char **notes, int *nptrs, int ch)
+{
+	unsigned char n1, n2;
+	int rest = 0;
+
+	n1 = notes[ch][nptrs[ch]++];
+
+	if ( n1 & 0xf8 ) {
+		n2 = notes[ch][nptrs[ch]++];
+	} else {
+		rest = 1;
+	}
+
+	if ( rest ) {
+		printf("rest %i\n", n1);
+	} else {
+		printf("note %i:%i\n", n1, n2);
+	}
+}
+
+
+static void interpret_gates(unsigned char *gates, unsigned char **notes,
+                            int n_gates)
+{
+	int i;
+	int ma = 0;
+	int nptrs[8];
+
+	for ( i=0; i<8; i++ ) nptrs[i] = 0;
+
+	for ( i=0; i<n_gates; i++ ) {
+
+		if ( ma ) {
+			music_attribute(gates[i]);
+			ma = 0;
+			continue;
+		}
+
+		if ( gates[i] == 0 ) {
+			ma = 1;
+			continue;
+		} else {
+
+			if ( gates[i] & 0x1 ) get_note(notes, nptrs, 0);
+			if ( gates[i] & 0x2 ) get_note(notes, nptrs, 1);
+			if ( gates[i] & 0x4 ) get_note(notes, nptrs, 2);
+			if ( gates[i] & 0x8 ) get_note(notes, nptrs, 3);
+			if ( gates[i] & 0x10 ) get_note(notes, nptrs, 4);
+			if ( gates[i] & 0x20 ) get_note(notes, nptrs, 5);
+			if ( gates[i] & 0x40 ) get_note(notes, nptrs, 6);
+			if ( gates[i] & 0x80 ) get_note(notes, nptrs, 7);
+
+		}
+	}
+}
+
+
 static size_t process_music_data(unsigned char *f, size_t ptr, size_t len)
 {
 	unsigned int n_gates;
 	unsigned int i;
 	unsigned int lengths[8];
+	unsigned char *gates;
+	unsigned char *notes[8];
 
 	n_gates = get_basic_int(f, &ptr);
 	printf("%i gates\n", n_gates);
@@ -84,19 +211,29 @@ static size_t process_music_data(unsigned char *f, size_t ptr, size_t len)
 		printf("Channel %i, length %i\n", i+1, lengths[i]);
 	}
 
+	gates = malloc(n_gates);
+	if ( gates == NULL ) {
+		fprintf(stderr, "Failed to allocate gates\n");
+	}
 	for ( i=0; i<n_gates; i++ ) {
-		unsigned char gd;
-		gd = f[ptr++];
+		gates[i] = f[ptr++];
 	}
 
 	for ( i=0; i<8; i++ ) {
+
 		unsigned int j;
+
+		notes[i] = malloc(lengths[i]);
+		if ( notes[i] == NULL ) {
+			fprintf(stderr, "Failed to allocate notes\n");
+		}
 		for ( j=0; j<lengths[i]; j++ ) {
-			unsigned char d;
-			d = f[ptr++];
+			notes[i][j] = f[ptr++];
 		}
 	}
 
+	interpret_gates(gates, notes, n_gates);
+
 	return ptr;
 }
 
-- 
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