1 files changed, 67 insertions, 0 deletions
diff --git a/stm32/src/sfx.c b/stm32/src/sfx.c
new file mode 100644
index 0000000..f80c8d1
--- /dev/null
+++ b/stm32/src/sfx.c
@@ -0,0 +1,67 @@
+/*!
+ * Sound effect player library.
+ *
+ * This implements a state machine for playing back various monophonic
+ * sound effects such as morse code symbols, clicks and alert tones.
+ *
+ * Author Stuart Longland <[email protected]>
+ * Copyright (C) 2015 FreeDV project.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License version 2.1,
+ * as published by the Free Software Foundation.  This program is
+ * distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdlib.h>
+#include "sfx.h"
+
+static void sfx_next_tone(struct sfx_player_t* const sfx_player)
+{
+	struct tone_gen_t* tone_gen = &(sfx_player->tone_gen);
+	const struct sfx_note_t* note = sfx_player->note;
+
+	if (!note) {
+		tone_reset(tone_gen, 0, 0);
+	} else {
+		tone_reset(tone_gen, note->freq, note->duration);
+
+		if (!note->duration)
+			/* We are done */
+			sfx_player->note = NULL;
+		else
+			/* Move to next note */
+			sfx_player->note++;
+	}
+}
+
+/*!
+ * Start playing a particular effect.
+ * @param	sfx_player	Effect player state machine
+ * @param	effect		Pointer to sound effect (NULL == stop)
+ */
+void sfx_play(struct sfx_player_t* const sfx_player,
+		const struct sfx_note_t* effect)
+{
+	sfx_player->note = effect;
+	sfx_next_tone(sfx_player);
+}
+
+/*!
+ * Retrieve the next sample to be played.
+ */
+int16_t sfx_next(struct sfx_player_t* const sfx_player)
+{
+	if (!sfx_player)
+		return(0);
+	if (!sfx_player->tone_gen.remain)
+		sfx_next_tone(sfx_player);
+	return tone_next(&(sfx_player->tone_gen));
+}