添加一些关于midi播放的项目

2025-03-24 14:30:56 +08:00
parent e31eb22077
commit 498b4ef13b
699 changed files with 186162 additions and 1 deletions
@@ -0,0 +1,84 @@
+/*
+ *	Midi2Wave
+ *
+ *	Implementation
+ */
+
+
+#include "midi2wave.h"
+
+#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
+#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
+
+short ptr;
+
+void setupMidi() {
+	for (int i=0; i<MAX_NOTE; ++i)
+		key_vels[i] = 0;
+	for (char i=0; i<KEYBUF_SIZE; ++i)
+		active_keys[i] = 0;
+	ptr = 0;
+}
+
+void renderWaveBuffer() {
+	unsigned char leds = 0;
+	note_count = 0;
+	// Update active key buffer with new keys
+	// Preserve original index if the key is not released
+	for (char i = 0; i < KEYBUF_SIZE; ++i)
+		if (key_vels[active_keys[i]]) {
+			key_vels[active_keys[i]] |= 32; // the 6th bit is used as a "key-not-released" flag
+			leds |= 1<<(active_keys[i]%6);
+			++note_count;
+		}
+		else {
+			active_keys[i] = 0; // Clear keys that are released
+		}
+
+	for (int i=MAX_NOTE-1; i>=0; --i) // Goes down: make sure the most significant note gets played
+		if ( key_vels[i] && !(key_vels[i]&32) ) {
+			for (char j=0; j<KEYBUF_SIZE; j++)
+				if (!active_keys[j])
+				{
+					active_keys[j] = i;
+					++note_count;
+					break;
+				}
+			leds |= 1<<(i%6);
+		}
+
+	for (char i = 0; i < KEYBUF_SIZE; ++i)
+		if (active_keys[i])
+			key_vels[active_keys[i]] &= 31; // Clear out the 6th bit "key-not-released" flag
+
+	// Set LEDs
+	for (char i = 0; i < 7; ++i)
+		if (leds & (1<<i))
+			sbi(PORTD, i+2);
+		else
+			cbi(PORTD, i+2);
+}
+
+void loadNextEvent() {
+	if (ptr >= SONG_LEN)
+	{
+		// Restart in 3s
+		Serial.println("Ended.");
+		setupMidi();
+		event_length = 3000;
+		for (int i = 0; i < 7; ++i)
+			sbi(PORTD, i+2);
+		return;
+	}
+
+	int new_length = NOTE_DELAY(ptr)*TEMPO;
+	key_vels[NOTE_NUMBER(ptr)-1] = NOTE_VEL(ptr);
+
+	++ptr;
+	if (new_length == 0)
+		loadNextEvent();
+	else {
+		renderWaveBuffer();
+		event_length = new_length;
+	}
+}