1 files changed, 286 insertions, 0 deletions
diff --git a/scene/resources/audio_stream_polyphonic.cpp b/scene/resources/audio_stream_polyphonic.cpp
new file mode 100644
index 0000000000..2e56ff3423
--- /dev/null
+++ b/scene/resources/audio_stream_polyphonic.cpp
@@ -0,0 +1,286 @@
+/**************************************************************************/
+/*  audio_stream_polyphonic.cpp                                           */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#include "audio_stream_polyphonic.h"
+#include "scene/main/scene_tree.h"
+
+Ref<AudioStreamPlayback> AudioStreamPolyphonic::instantiate_playback() {
+	Ref<AudioStreamPlaybackPolyphonic> playback;
+	playback.instantiate();
+	playback->streams.resize(polyphony);
+	return playback;
+}
+
+String AudioStreamPolyphonic::get_stream_name() const {
+	return "AudioStreamPolyphonic";
+}
+
+bool AudioStreamPolyphonic::is_monophonic() const {
+	return true; // This avoids stream players to instantiate more than one of these.
+}
+
+void AudioStreamPolyphonic::set_polyphony(int p_voices) {
+	ERR_FAIL_COND(p_voices < 0 || p_voices > 128);
+	polyphony = p_voices;
+}
+int AudioStreamPolyphonic::get_polyphony() const {
+	return polyphony;
+}
+
+void AudioStreamPolyphonic::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_polyphony", "voices"), &AudioStreamPolyphonic::set_polyphony);
+	ClassDB::bind_method(D_METHOD("get_polyphony"), &AudioStreamPolyphonic::get_polyphony);
+
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "polyphony", PROPERTY_HINT_RANGE, "1,128,1"), "set_polyphony", "get_polyphony");
+}
+
+AudioStreamPolyphonic::AudioStreamPolyphonic() {
+}
+
+////////////////////////
+
+void AudioStreamPlaybackPolyphonic::start(double p_from_pos) {
+	if (active) {
+		stop();
+	}
+
+	active = true;
+}
+
+void AudioStreamPlaybackPolyphonic::stop() {
+	if (!active) {
+		return;
+	}
+
+	bool locked = false;
+	for (Stream &s : streams) {
+		if (s.active.is_set()) {
+			// Need locking because something may still be mixing.
+			locked = true;
+			AudioServer::get_singleton()->lock();
+		}
+		s.active.clear();
+		s.finalizing.clear();
+		s.finish_request.clear();
+		s.stream_playback.unref();
+		s.stream.unref();
+	}
+	if (locked) {
+		AudioServer::get_singleton()->unlock();
+	}
+
+	active = false;
+}
+
+bool AudioStreamPlaybackPolyphonic::is_playing() const {
+	return active;
+}
+
+int AudioStreamPlaybackPolyphonic::get_loop_count() const {
+	return 0;
+}
+
+double AudioStreamPlaybackPolyphonic::get_playback_position() const {
+	return 0;
+}
+void AudioStreamPlaybackPolyphonic::seek(double p_time) {
+	// Ignored.
+}
+
+void AudioStreamPlaybackPolyphonic::tag_used_streams() {
+	for (Stream &s : streams) {
+		if (s.active.is_set()) {
+			s.stream_playback->tag_used_streams();
+		}
+	}
+}
+
+int AudioStreamPlaybackPolyphonic::mix(AudioFrame *p_buffer, float p_rate_scale, int p_frames) {
+	if (!active) {
+		return 0;
+	}
+
+	// Pre-clear buffer.
+	for (int i = 0; i < p_frames; i++) {
+		p_buffer[i] = AudioFrame(0, 0);
+	}
+
+	for (Stream &s : streams) {
+		if (!s.active.is_set()) {
+			continue;
+		}
+
+		float volume_db = s.volume_db; // Copy because it can be overriden at any time.
+		float next_volume = Math::db_to_linear(volume_db);
+		s.prev_volume_db = volume_db;
+
+		if (s.finish_request.is_set()) {
+			if (s.pending_play.is_set()) {
+				// Did not get the chance to play, was finalized too soon.
+				s.active.clear();
+				s.finalizing.set();
+				continue;
+			}
+			next_volume = 0;
+		}
+
+		if (s.pending_play.is_set()) {
+			s.stream_playback->start(s.play_offset);
+			s.pending_play.clear();
+		}
+		float prev_volume = Math::db_to_linear(s.prev_volume_db);
+
+		float volume_inc = (next_volume - prev_volume) / float(p_frames);
+
+		int todo = p_frames;
+		int offset = 0;
+		float volume = prev_volume;
+
+		while (todo) {
+			int to_mix = MIN(todo, int(INTERNAL_BUFFER_LEN));
+			int mixed = s.stream_playback->mix(internal_buffer, s.pitch_scale, to_mix);
+
+			for (int i = 0; i < to_mix; i++) {
+				p_buffer[offset + i] += internal_buffer[i] * volume;
+				volume += volume_inc;
+			}
+
+			if (mixed < to_mix) {
+				// Stream is done.
+				s.active.clear();
+				s.finalizing.set();
+				break;
+			}
+
+			todo -= to_mix;
+			offset += to_mix;
+		}
+
+		if (s.finish_request.is_set()) {
+			s.active.clear();
+			s.finalizing.set();
+		}
+	}
+
+	return p_frames;
+}
+
+void AudioStreamPlaybackPolyphonic::_check_finalized_streams() {
+	if (!active) {
+		return;
+	}
+
+	for (Stream &s : streams) {
+		if (!s.active.is_set() && s.finalizing.is_set()) {
+			s.stream_playback.unref();
+			s.stream.unref();
+			s.finalizing.clear();
+			s.finish_request.clear();
+		}
+	}
+}
+
+AudioStreamPlaybackPolyphonic::ID AudioStreamPlaybackPolyphonic::play_stream(const Ref<AudioStream> &p_stream, float p_from_offset, float p_volume_db, float p_pitch_scale) {
+	ERR_FAIL_COND_V(p_stream.is_null(), INVALID_ID);
+	for (uint32_t i = 0; i < streams.size(); i++) {
+		if (!streams[i].active.is_set() && !streams[i].finish_request.is_set() && !streams[i].finalizing.is_set()) {
+			// Can use this stream, as it's not active.
+			streams[i].stream = p_stream;
+			streams[i].stream_playback = streams[i].stream->instantiate_playback();
+			streams[i].play_offset = p_from_offset;
+			streams[i].volume_db = p_volume_db;
+			streams[i].prev_volume_db = p_volume_db;
+			streams[i].pitch_scale = p_pitch_scale;
+			streams[i].id = id_counter++;
+			streams[i].pending_play.set();
+			streams[i].active.set();
+			return (ID(i) << INDEX_SHIFT) | ID(streams[i].id);
+		}
+	}
+
+	return INVALID_ID;
+}
+
+AudioStreamPlaybackPolyphonic::Stream *AudioStreamPlaybackPolyphonic::_find_stream(int64_t p_id) {
+	uint32_t index = p_id >> INDEX_SHIFT;
+	if (index >= streams.size()) {
+		return nullptr;
+	}
+	if (!streams[index].active.is_set()) {
+		return nullptr; // Not active, no longer exists.
+	}
+	int64_t id = p_id & ID_MASK;
+	if (streams[index].id != id) {
+		return nullptr;
+	}
+	return &streams[index];
+}
+
+void AudioStreamPlaybackPolyphonic::set_stream_volume(ID p_stream_id, float p_volume_db) {
+	Stream *s = _find_stream(p_stream_id);
+	if (!s) {
+		return;
+	}
+	s->volume_db = p_volume_db;
+}
+
+void AudioStreamPlaybackPolyphonic::set_stream_pitch_scale(ID p_stream_id, float p_pitch_scale) {
+	Stream *s = _find_stream(p_stream_id);
+	if (!s) {
+		return;
+	}
+	s->pitch_scale = p_pitch_scale;
+}
+
+bool AudioStreamPlaybackPolyphonic::is_stream_playing(ID p_stream_id) const {
+	return const_cast<AudioStreamPlaybackPolyphonic *>(this)->_find_stream(p_stream_id) != nullptr;
+}
+
+void AudioStreamPlaybackPolyphonic::stop_stream(ID p_stream_id) {
+	Stream *s = _find_stream(p_stream_id);
+	if (!s) {
+		return;
+	}
+	s->finish_request.set();
+}
+
+void AudioStreamPlaybackPolyphonic::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("play_stream", "stream", "from_offset", "volume_db", "pitch_scale"), &AudioStreamPlaybackPolyphonic::play_stream, DEFVAL(0), DEFVAL(0), DEFVAL(1.0));
+	ClassDB::bind_method(D_METHOD("set_stream_volume", "stream", "volume_db"), &AudioStreamPlaybackPolyphonic::set_stream_volume);
+	ClassDB::bind_method(D_METHOD("set_stream_pitch_scale", "stream", "pitch_scale"), &AudioStreamPlaybackPolyphonic::set_stream_pitch_scale);
+	ClassDB::bind_method(D_METHOD("is_stream_playing", "stream"), &AudioStreamPlaybackPolyphonic::is_stream_playing);
+	ClassDB::bind_method(D_METHOD("stop_stream", "stream"), &AudioStreamPlaybackPolyphonic::stop_stream);
+
+	BIND_CONSTANT(INVALID_ID);
+}
+
+AudioStreamPlaybackPolyphonic::AudioStreamPlaybackPolyphonic() {
+	SceneTree::get_singleton()->connect(SNAME("process_frame"), callable_mp(this, &AudioStreamPlaybackPolyphonic::_check_finalized_streams));
+}