OpenAL sound: Use a simpler distance model

In createPlayingSoundAt(), AL_ROLLOFF_FACTOR is not set, so it has the default value of 1.0, this makes the equation of the currently used AL_EXPONENT_DISTANCE distance model identical to the equation of the simpler AL_INVERSE_DISTANCE distance model. Using AL_INVERSE_DISTANCE means an exponent is not processed, exponents are quite intensive to process. There is no change in sound attenuation behaviour. The commented-out AL_ROLLOFF_FACTOR value is removed as it would now have a different effect if used.
minetest · Feb 9, 2017 · a5ee713 · a5ee713
1 parent e2ad76f
commit a5ee713
Showing 1 changed file with 1 addition and 2 deletions.
diff --git a/src/sound_openal.cpp b/src/sound_openal.cpp
@@ -317,7 +317,7 @@ class OpenALSoundManager: public ISoundManager
 			return;
 		}
 
-		alDistanceModel(AL_EXPONENT_DISTANCE);
+		alDistanceModel(AL_INVERSE_DISTANCE);
 
 		infostream<<"Audio: Initialized: OpenAL "<<alGetString(AL_VERSION)
 				<<", using "<<alcGetString(m_device, ALC_DEVICE_SPECIFIER)
@@ -409,7 +409,6 @@ class OpenALSoundManager: public ISoundManager
 		alSourcei(sound->source_id, AL_SOURCE_RELATIVE, false);
 		alSource3f(sound->source_id, AL_POSITION, pos.X, pos.Y, pos.Z);
 		alSource3f(sound->source_id, AL_VELOCITY, 0, 0, 0);
-		//alSourcef(sound->source_id, AL_ROLLOFF_FACTOR, 0.7);
 		alSourcef(sound->source_id, AL_REFERENCE_DISTANCE, 30.0);
 		alSourcei(sound->source_id, AL_LOOPING, loop ? AL_TRUE : AL_FALSE);
 		volume = MYMAX(0.0, volume);