Added generator audio stream, and spectrum analyzer audio effect

Made AudioFrame and Vector2 equivalent for casting.
Added ability to obtain the playback object from stream players.
Added ability to obtain effect instance from audio server.

1 files changed, 182 insertions, 0 deletions

diff --git a/servers/audio/effects/audio_stream_generator.cpp b/servers/audio/effects/audio_stream_generator.cpp
new file mode 100644
index 0000000000..f4a66b5643
--- /dev/null
+++ b/servers/audio/effects/audio_stream_generator.cpp
@@ -0,0 +1,182 @@
+#include "audio_stream_generator.h"
+
+void AudioStreamGenerator::set_mix_rate(float p_mix_rate) {
+	mix_rate = p_mix_rate;
+}
+
+float AudioStreamGenerator::get_mix_rate() const {
+
+	return mix_rate;
+}
+
+void AudioStreamGenerator::set_buffer_length(float p_seconds) {
+
+	buffer_len = p_seconds;
+}
+float AudioStreamGenerator::get_buffer_length() const {
+
+	return buffer_len;
+}
+
+Ref<AudioStreamPlayback> AudioStreamGenerator::instance_playback() {
+
+	Ref<AudioStreamGeneratorPlayback> playback;
+	playback.instance();
+	playback->generator = this;
+	int target_buffer_size = mix_rate * buffer_len;
+	playback->buffer.resize(nearest_shift(target_buffer_size));
+	playback->buffer.clear();
+	return playback;
+}
+String AudioStreamGenerator::get_stream_name() const {
+
+	return "UserFeed";
+}
+
+float AudioStreamGenerator::get_length() const {
+	return 0;
+}
+
+void AudioStreamGenerator::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_mix_rate", "hz"), &AudioStreamGenerator::set_mix_rate);
+	ClassDB::bind_method(D_METHOD("get_mix_rate"), &AudioStreamGenerator::get_mix_rate);
+
+	ClassDB::bind_method(D_METHOD("set_buffer_length", "seconds"), &AudioStreamGenerator::set_buffer_length);
+	ClassDB::bind_method(D_METHOD("get_buffer_length"), &AudioStreamGenerator::get_buffer_length);
+
+	ADD_PROPERTY(PropertyInfo(Variant::REAL, "mix_rate", PROPERTY_HINT_RANGE, "20,192000,1"), "set_mix_rate", "get_mix_rate");
+	ADD_PROPERTY(PropertyInfo(Variant::REAL, "buffer_length", PROPERTY_HINT_RANGE, "0.01,10,0.01"), "set_buffer_length", "get_buffer_length");
+}
+
+AudioStreamGenerator::AudioStreamGenerator() {
+	mix_rate = 44100;
+	buffer_len = 0.5;
+}
+
+////////////////
+
+bool AudioStreamGeneratorPlayback::push_frame(const Vector2 &p_frame) {
+	if (buffer.space_left() < 1) {
+		return false;
+	}
+
+	AudioFrame f = p_frame;
+
+	buffer.write(&f, 1);
+	return true;
+}
+
+bool AudioStreamGeneratorPlayback::can_push_buffer(int p_frames) const {
+	return buffer.space_left() >= p_frames;
+}
+bool AudioStreamGeneratorPlayback::push_buffer(const PoolVector2Array &p_frames) {
+
+	int to_write = p_frames.size();
+	if (buffer.space_left() < to_write) {
+		return false;
+	}
+
+	PoolVector2Array::Read r = p_frames.read();
+	if (sizeof(real_t) == 4) {
+		//write directly
+		buffer.write((const AudioFrame *)r.ptr(), to_write);
+	} else {
+		//convert from double
+		AudioFrame buf[2048];
+		int ofs = 0;
+		while (to_write) {
+
+			int w = MIN(to_write, 2048);
+			for (int i = 0; i < w; i++) {
+				buf[i] = r[i + ofs];
+			}
+			buffer.write(buf, w);
+			ofs += w;
+			to_write -= w;
+		}
+	}
+	return true;
+}
+
+int AudioStreamGeneratorPlayback::get_frames_available() const {
+	return buffer.space_left();
+}
+
+int AudioStreamGeneratorPlayback::get_skips() const {
+	return skips;
+}
+
+void AudioStreamGeneratorPlayback::clear_buffer() {
+	ERR_FAIL_COND(active);
+	buffer.clear();
+	mixed = 0;
+}
+
+void AudioStreamGeneratorPlayback::_mix_internal(AudioFrame *p_buffer, int p_frames) {
+
+	int read_amount = buffer.data_left();
+	if (p_frames < read_amount) {
+		read_amount = p_frames;
+	}
+
+	buffer.read(p_buffer, read_amount);
+
+	if (read_amount < p_frames) {
+		//skipped, not ideal
+		for (int i = read_amount; i < p_frames; i++) {
+			p_buffer[i] = AudioFrame(0, 0);
+		}
+
+		skips++;
+	}
+
+	mixed += p_frames / generator->get_mix_rate();
+}
+float AudioStreamGeneratorPlayback::get_stream_sampling_rate() {
+	return generator->get_mix_rate();
+}
+
+void AudioStreamGeneratorPlayback::start(float p_from_pos) {
+
+	if (mixed == 0.0) {
+		_begin_resample();
+	}
+	skips = 0;
+	active = true;
+	mixed = 0.0;
+}
+
+void AudioStreamGeneratorPlayback::stop() {
+	active = false;
+}
+bool AudioStreamGeneratorPlayback::is_playing() const {
+
+	return active; //always playing, can't be stopped
+}
+
+int AudioStreamGeneratorPlayback::get_loop_count() const {
+	return 0;
+}
+
+float AudioStreamGeneratorPlayback::get_playback_position() const {
+	return mixed;
+}
+void AudioStreamGeneratorPlayback::seek(float p_time) {
+	//no seek possible
+}
+
+void AudioStreamGeneratorPlayback::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("push_frame", "frame"), &AudioStreamGeneratorPlayback::push_frame);
+	ClassDB::bind_method(D_METHOD("can_push_buffer", "amount"), &AudioStreamGeneratorPlayback::can_push_buffer);
+	ClassDB::bind_method(D_METHOD("push_buffer", "frames"), &AudioStreamGeneratorPlayback::push_buffer);
+	ClassDB::bind_method(D_METHOD("get_frames_available"), &AudioStreamGeneratorPlayback::get_frames_available);
+	ClassDB::bind_method(D_METHOD("get_skips"), &AudioStreamGeneratorPlayback::get_skips);
+	ClassDB::bind_method(D_METHOD("clear_buffer"), &AudioStreamGeneratorPlayback::clear_buffer);
+}
+
+AudioStreamGeneratorPlayback::AudioStreamGeneratorPlayback() {
+	generator = NULL;
+	skips = 0;
+	active = false;
+	mixed = 0;
+}