Implement AL_AIR_ABSORPTION_FACTOR source property

4 files changed, 21 insertions, 0 deletions

diff --git a/Alc/ALu.c b/Alc/ALu.c
index 7397af8f..b65070a8 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -378,6 +378,10 @@ static ALvoid CalcSourceParams(ALCcontext *ALContext, ALsource *ALSource,
                 break;
         }
 
+        if(ALSource->AirAbsorptionFactor > 0.0f)
+            DryGainHF *= pow(ALSource->AirAbsorptionFactor * AIRABSORBGAINHF,
+                             Distance * MetersPerUnit);
+
         *drygainhf = DryGainHF;
         *wetgainhf = WetGainHF;
 
diff --git a/OpenAL32/Include/alMain.h b/OpenAL32/Include/alMain.h
index 8ffda560..5a221065 100644
--- a/OpenAL32/Include/alMain.h
+++ b/OpenAL32/Include/alMain.h
@@ -98,6 +98,7 @@ extern char szDebug[256];
 //#define OUTPUT_BUFFER_SIZE         (32768*SWMIXER_OUTPUT_RATE/22050)
 
 #define SPEEDOFSOUNDMETRESPERSEC   (343.3f)
+#define AIRABSORBGAINHF            (0.994f)
 
 typedef struct {
     ALCboolean (*OpenPlayback)(ALCdevice*, const ALCchar*);
diff --git a/OpenAL32/Include/alSource.h b/OpenAL32/Include/alSource.h
index 4493c006..38b0094d 100644
--- a/OpenAL32/Include/alSource.h
+++ b/OpenAL32/Include/alSource.h
@@ -68,6 +68,8 @@ typedef struct ALsource_struct
     ALboolean DryGainHFAuto;
     ALfloat   OuterGainHF;
 
+    ALfloat AirAbsorptionFactor;
+
     // Index to itself
     ALuint source;
 
diff --git a/OpenAL32/alSource.c b/OpenAL32/alSource.c
index 1e30b1db..65bfcb22 100644
--- a/OpenAL32/alSource.c
+++ b/OpenAL32/alSource.c
@@ -348,6 +348,13 @@ ALAPI ALvoid ALAPIENTRY alSourcef(ALuint source, ALenum eParam, ALfloat flValue)
                     alSetError(AL_INVALID_VALUE);
                 break;
 
+            case AL_AIR_ABSORPTION_FACTOR:
+                if (flValue >= 0.0f && flValue <= 10.0f)
+                    pSource->AirAbsorptionFactor = flValue;
+                else
+                    alSetError(AL_INVALID_VALUE);
+                break;
+
             case AL_SEC_OFFSET:
             case AL_SAMPLE_OFFSET:
             case AL_BYTE_OFFSET:
@@ -472,6 +479,7 @@ ALAPI ALvoid ALAPIENTRY alSourcefv(ALuint source, ALenum eParam, const ALfloat *
                 case AL_SEC_OFFSET:
                 case AL_SAMPLE_OFFSET:
                 case AL_BYTE_OFFSET:
+                case AL_AIR_ABSORPTION_FACTOR:
                     alSourcef(source, eParam, pflValues[0]);
                     break;
 
@@ -850,6 +858,10 @@ ALAPI ALvoid ALAPIENTRY alGetSourcef(ALuint source, ALenum eParam, ALfloat *pflV
                     *pflValue = pSource->flRefDistance;
                     break;
 
+                case AL_AIR_ABSORPTION_FACTOR:
+                    *pflValue = pSource->AirAbsorptionFactor;
+                    break;
+
                 default:
                     alSetError(AL_INVALID_ENUM);
                     break;
@@ -958,6 +970,7 @@ ALAPI ALvoid ALAPIENTRY alGetSourcefv(ALuint source, ALenum eParam, ALfloat *pfl
                 case AL_CONE_OUTER_ANGLE:
                 case AL_REFERENCE_DISTANCE:
                 case AL_CONE_OUTER_GAINHF:
+                case AL_AIR_ABSORPTION_FACTOR:
                     alGetSourcef(source, eParam, pflValues);
                     break;
 
@@ -1879,6 +1892,7 @@ static ALvoid InitSourceParams(ALsource *pSource)
     pSource->flOuterGain = 0.0f;
 
     pSource->DryGainHFAuto = AL_TRUE;
+    pSource->AirAbsorptionFactor = 0.0f;
 
     pSource->state = AL_INITIAL;
     pSource->lSourceType = AL_UNDETERMINED;