From 045a6ec084bf1fb4df3c6ade4a88932cf61bed23 Mon Sep 17 00:00:00 2001
From: Daniel Karbach <daniel.karbach@localhorst.tv>
Date: Fri, 14 Aug 2015 11:39:39 +0200
Subject: [PATCH] the sound thing

---
 TODO                      |  5 ----
 src/app/IntervalTimer.hpp |  4 ++--
 src/app/app.cpp           |  1 +
 src/audio/Audio.hpp       | 11 ++++++++-
 src/audio/Sound.hpp       |  4 ++++
 src/audio/audio.cpp       | 49 ++++++++++++++++++++++++++++++++++++---
 6 files changed, 63 insertions(+), 11 deletions(-)

diff --git a/TODO b/TODO
index 9bd2aaa..b77cdae 100644
--- a/TODO
+++ b/TODO
@@ -21,11 +21,6 @@ command line
 
 	usefull for development and later on world administration
 
-audio
-
-	do the sources thing right™
-	(or at least in a way that it doesn't error out on shutdown :P )
-
 persistence
 
 	merge IO counters, so number of operations per frame is kept
diff --git a/src/app/IntervalTimer.hpp b/src/app/IntervalTimer.hpp
index bcf1bae..06caa5e 100644
--- a/src/app/IntervalTimer.hpp
+++ b/src/app/IntervalTimer.hpp
@@ -13,7 +13,7 @@ class IntervalTimer {
 public:
 	/// Create a timer that hits every interval_ms milliseconds.
 	/// Initial state is stopped.
-	explicit IntervalTimer(int interval_ms) noexcept
+	explicit IntervalTimer(int interval_ms = 0) noexcept
 	: intv(interval_ms) { }
 
 	void Start() noexcept {
@@ -35,7 +35,7 @@ public:
 		return Running() && value % intv < last_dt;
 	}
 	bool HitOnce() const noexcept {
-		return value >= intv;
+		return Running() && value >= intv;
 	}
 	int Elapsed() const noexcept {
 		return value;
diff --git a/src/app/app.cpp b/src/app/app.cpp
index 8f3801c..a6acade 100644
--- a/src/app/app.cpp
+++ b/src/app/app.cpp
@@ -129,6 +129,7 @@ void Application::Handle(const SDL_WindowEvent &event) {
 
 void Application::Update(int dt) {
 	env.counter.EnterUpdate();
+	env.audio.Update(dt);
 	if (HasState()) {
 		GetState().Update(dt);
 	}
diff --git a/src/audio/Audio.hpp b/src/audio/Audio.hpp
index fe5364d..bfd6d47 100644
--- a/src/audio/Audio.hpp
+++ b/src/audio/Audio.hpp
@@ -1,6 +1,8 @@
 #ifndef BLANK_AUDIO_AUDIO_HPP_
 #define BLANK_AUDIO_AUDIO_HPP_
 
+#include "../app/IntervalTimer.hpp"
+
 #include <al.h>
 #include <glm/glm.hpp>
 
@@ -32,9 +34,16 @@ public:
 
 	void StopAll() noexcept;
 
+	void Update(int dt) noexcept;
+
+private:
+	int NextFree() noexcept;
+
 private:
-	static constexpr std::size_t NUM_SRC = 1;
+	static constexpr std::size_t NUM_SRC = 16;
 	ALuint source[NUM_SRC];
+	IntervalTimer timer[NUM_SRC];
+	int last_free;
 
 };
 
diff --git a/src/audio/Sound.hpp b/src/audio/Sound.hpp
index abbb27b..abd3178 100644
--- a/src/audio/Sound.hpp
+++ b/src/audio/Sound.hpp
@@ -22,8 +22,12 @@ public:
 public:
 	void Bind(ALuint src) const;
 
+	/// full duration in milliseconds
+	int Duration() const noexcept { return duration; }
+
 private:
 	ALuint handle;
+	int duration;
 
 };
 
diff --git a/src/audio/audio.cpp b/src/audio/audio.cpp
index eed5dac..426745f 100644
--- a/src/audio/audio.cpp
+++ b/src/audio/audio.cpp
@@ -92,14 +92,23 @@ void Audio::Play(
 	const glm::vec3 &vel,
 	const glm::vec3 &dir
 ) noexcept {
-	// TODO: find next free source
-	ALuint src = source[0];
+	int i = NextFree();
+	if (i < 0) {
+		std::cerr << "unable to find free audio source" << std::endl;
+		return;
+	}
+
+	ALuint src = source[i];
+	IntervalTimer &t = timer[i];
 
 	sound.Bind(src);
 	alSourcefv(src, AL_POSITION, glm::value_ptr(pos));
 	alSourcefv(src, AL_VELOCITY, glm::value_ptr(vel));
 	alSourcefv(src, AL_DIRECTION, glm::value_ptr(dir));
 	alSourcePlay(src);
+
+	t = IntervalTimer(sound.Duration());
+	t.Start();
 }
 
 void Audio::StopAll() noexcept {
@@ -109,9 +118,35 @@ void Audio::StopAll() noexcept {
 	}
 }
 
+void Audio::Update(int dt) noexcept {
+	for (std::size_t i = 0; i < NUM_SRC; ++i) {
+		timer[i].Update(dt);
+		if (timer[i].HitOnce()) {
+			timer[i].Stop();
+			alSourceStop(source[i]);
+			alSourcei(source[i], AL_BUFFER, AL_NONE);
+			last_free = i;
+		}
+	}
+}
+
+int Audio::NextFree() noexcept {
+	if (!timer[last_free].Running()) {
+		return last_free;
+	}
+	for (int i = (last_free + 1) % NUM_SRC; i != last_free; i = (i + 1) % NUM_SRC) {
+		if (!timer[i].Running()) {
+			last_free = i;
+			return i;
+		}
+	}
+	return -1;
+}
+
 
 Sound::Sound()
-: handle(AL_NONE) {
+: handle(AL_NONE)
+, duration(0) {
 	alGenBuffers(1, &handle);
 	ALenum err = alGetError();
 	if (err != AL_NO_ERROR) {
@@ -124,6 +159,14 @@ Sound::Sound(const char *file)
 	if (handle == AL_NONE) {
 		throw ALError(alGetError(), "alutCreateBufferFromFile");
 	}
+
+	ALint size, channels, bits, freq;
+	alGetBufferi(handle, AL_SIZE, &size);
+	alGetBufferi(handle, AL_CHANNELS, &channels);
+	alGetBufferi(handle, AL_BITS, &bits);
+	alGetBufferi(handle, AL_FREQUENCY, &freq);
+
+	duration = size * 8 * 1000 / (channels * bits * freq);
 }
 
 Sound::~Sound() {
-- 
2.39.2