improved setup time by 1.4 seconds through threading

audio/AudioMixer.h

@@ -12,10 +12,17 @@
 #include "../stdlib/Types.h"
 #include "Audio.h"
 #include "AudioSetting.h"
+#include "../utils/Utils.h"
 #include "../utils/MathUtils.h"
 #include "../memory/ChunkMemory.h"
 #include "../math/matrix/MatrixFloat32.h"
 
+#if _WIN32
+    #include "../platform/win32/threading/Atomic.h"
+#elif __linux__
+    #include "../platform/linux/threading/Atomic.h"
+#endif
+
 #if DIRECT_SOUND
     #include "../platform/win32/audio/DirectSound.h"
 #elif XAUDIO2
@@ -52,9 +59,17 @@ struct AudioInstance {
     uint32 sample_index;
 };
 
+enum AudioMixerState {
+    AUDIO_MIXER_STATE_UNINITIALIZED,
+    AUDIO_MIXER_STATE_INACTIVE,
+    AUDIO_MIXER_STATE_SHOULD_PLAY,
+    AUDIO_MIXER_STATE_ACTIVE,
+};
+
 struct AudioMixer {
     ChunkMemory audio_instances;
-    bool is_active;
+    AudioMixerState state_old;
+    AudioMixerState state_new;
 
     uint64 effect;
 
@@ -67,12 +82,43 @@ struct AudioMixer {
         XAudio2Setting api_setting;
     #endif
 
+    // @todo Replace HWND with our own typedef for linux
+    HWND window;
+
     int16* buffer_temp;
 
     // @todo add mutex for locking and create threaded functions
     // do we need a condition or semaphore?
 };
 
+bool audio_mixer_is_active(AudioMixer* mixer) {
+    if (mixer->state_new == AUDIO_MIXER_STATE_ACTIVE
+        && atomic_get((int32 *) &mixer->state_new) == AUDIO_MIXER_STATE_ACTIVE
+    ) {
+        return true;
+    }
+
+    AudioMixerState mixer_state;
+    if ((mixer_state = (AudioMixerState) atomic_get((int32 *) &mixer->state_new)) != mixer->state_old) {
+        if (mixer_state != AUDIO_MIXER_STATE_UNINITIALIZED) {
+            audio_load(
+                mixer->window,
+                &mixer->settings,
+                &mixer->api_setting
+            );
+
+            mixer_state = AUDIO_MIXER_STATE_INACTIVE;
+        }
+
+        if (mixer_state == AUDIO_MIXER_STATE_ACTIVE) {
+            audio_play(&mixer->settings, &mixer->api_setting);
+            mixer_state = AUDIO_MIXER_STATE_ACTIVE;
+        }
+    }
+
+    return (mixer->state_old = mixer_state) == AUDIO_MIXER_STATE_ACTIVE;
+}
+
 // @todo expand AudioLocationSetting so that it also includes audio effects, repeat etc.
 void audio_mixer_add(AudioMixer* mixer, int64 id, Audio* audio, AudioLocationSetting* origin)
 {

platform/win32/threading/Atomic.h

@@ -151,11 +151,26 @@ void atomic_sub(volatile int64* value, int64 decrement) {
     InterlockedAdd((long *) value, -1 * ((long) decrement));
 }
 
+inline
+f32 atomic_compare_exchange_weak(volatile f32* value, f32* expected, f32 desired) {
+    return (f32) InterlockedCompareExchange((long *) value, (long) desired, (long) *expected);
+}
+
+inline
+f64 atomic_compare_exchange_weak(volatile f64* value, f64* expected, f64 desired) {
+    return (f64) InterlockedCompareExchange((long *) value, (long) desired, (long) *expected);
+}
+
 inline
 int32 atomic_compare_exchange_weak(volatile int32* value, int32* expected, int32 desired) {
     return (int32) InterlockedCompareExchange((long *) value, desired, *expected);
 }
 
+inline
+int64 atomic_compare_exchange_weak(volatile int64* value, int64* expected, int64 desired) {
+    return (int64) InterlockedCompareExchange((long *) value, (long) desired, (long) *expected);
+}
+
 inline
 int32 atomic_fetch_add(volatile int32* value, int32 operand) {
     return (int32) InterlockedExchangeAdd((long *) value, operand);
@@ -257,6 +272,11 @@ uint32 atomic_compare_exchange_weak(volatile uint32* value, uint32* expected, ui
     return (uint32) InterlockedCompareExchange((long *) value, desired, *expected);
 }
 
+inline
+uint64 atomic_compare_exchange_weak(volatile uint64* value, uint64* expected, uint64 desired) {
+    return (uint64) InterlockedCompareExchange((unsigned long long *) value, (unsigned long long) desired, (unsigned long long) *expected);
+}
+
 inline
 uint32 atomic_fetch_add(volatile uint32* value, uint32 operand) {
     return (uint32) InterlockedExchangeAdd((long *) value, operand);