1 files changed, 100 insertions, 0 deletions
diff --git a/Runtime/Audio/AudioSource.Callbacks.cpp b/Runtime/Audio/AudioSource.Callbacks.cpp
new file mode 100644
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+++ b/Runtime/Audio/AudioSource.Callbacks.cpp
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+/*
+ *  AudioSource.Callbacks.cpp
+ *  Xcode
+ *
+ *  Created by Søren Christiansen on 10/12/09.
+ *  Copyright 2009 Unity Technologies. All rights reserved.
+ *
+ */
+#include "UnityPrefix.h"
+#include "Configuration/UnityConfigure.h"
+#if ENABLE_AUDIO
+#include "AudioSource.h"
+#include "AudioManager.h"
+#include "Runtime/Utilities/Utility.h"
+
+/**
+ * Do log, linear and custom rolloff calculation to avoid interpolating the (animation)curve
+ **/
+float AudioSource::CalculateVolumeModifierForDistance(float distance)
+{	
+	float maxDistance, minDistance, rolloffScale;
+	RolloffMode rolloffMode;	
+	
+	rolloffScale = GetAudioManager().GetRolloffScale();
+	
+	maxDistance = GetMaxDistance();
+	minDistance = GetMinDistance();
+	rolloffMode = GetRolloffMode();	
+		
+	register float gain = 1.0f;
+	
+	switch (rolloffMode) {
+		case kRolloffLinear:
+			{
+				float range = maxDistance-minDistance;
+				if (range<=0) 
+					gain=1.0f;
+				else
+				{
+					distance = maxDistance - distance;
+					gain = distance / range;
+				}
+			}
+			break;
+		case kRolloffLogarithmic:
+			{
+				if ((distance > minDistance) && (rolloffScale != 1.0f))
+				{
+					distance -= minDistance;
+					distance *= rolloffScale;
+					distance += minDistance;
+				} 
+				
+				if (distance < .000001f)
+				{
+					distance = .000001f;
+				}
+				gain = minDistance / distance;
+			}
+			break;
+		case kRolloffCustom:
+			{
+				//@TODO: maxDistance can be 0.0F in that case the audio will play back incorrectly because gain becomes nan
+				if (maxDistance > 0.0F) 
+				{
+					const AnimationCurve& curve = GetCustomRolloffCurve();
+					gain = curve.Evaluate(distance / maxDistance);
+				}
+			}			
+			break;
+		default:
+			break;
+	}
+	
+	Assert(IsFinite(gain));
+	
+	if (gain < 0.0f)
+		gain = 0.0f;
+	if (gain > 1.0f)
+		gain = 1.0f;
+	
+	return gain;	
+}
+
+#if ENABLE_AUDIO_FMOD
+float F_CALLBACK AudioSource::rolloffCallback( 
+											  FMOD_CHANNEL *  c_channel,  
+											  float  distance)
+{	
+	FMOD::Channel* channel = (FMOD::Channel*)c_channel;
+	AudioSource* audioSource = AudioSource::GetAudioSourceFromChannel(channel);
+	
+	if (audioSource == NULL)
+		return 0.0f;
+	
+	return audioSource->CalculateVolumeModifierForDistance(distance);
+}
+
+#endif
+#endif //ENABLE_AUDIO