diff --git a/assignment-client/src/audio/AudioMixerSlave.cpp b/assignment-client/src/audio/AudioMixerSlave.cpp index b897efe197..42e8c5bdef 100644 --- a/assignment-client/src/audio/AudioMixerSlave.cpp +++ b/assignment-client/src/audio/AudioMixerSlave.cpp @@ -32,6 +32,7 @@ #include "AudioMixerClientData.h" #include "AvatarAudioStream.h" #include "InjectedAudioStream.h" +#include "AudioHelpers.h" #include "AudioMixerSlave.h" @@ -406,63 +407,6 @@ void AudioMixerSlave::addStreamToMix(AudioMixerClientData& listenerNodeData, con AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL); } -const int IEEE754_MANT_BITS = 23; -const int IEEE754_EXPN_BIAS = 127; - -// -// for x > 0.0f, returns log2(x) -// for x <= 0.0f, returns large negative value -// -// abs |error| < 8e-3, smooth (exact for x=2^N) for NPOLY=3 -// abs |error| < 2e-4, smooth (exact for x=2^N) for NPOLY=5 -// rel |error| < 0.4 from precision loss very close to 1.0f -// -static inline float fastlog2(float x) { - - union { float f; int32_t i; } mant, bits = { x }; - - // split into mantissa and exponent - mant.i = (bits.i & ((1 << IEEE754_MANT_BITS) - 1)) | (IEEE754_EXPN_BIAS << IEEE754_MANT_BITS); - int32_t expn = (bits.i >> IEEE754_MANT_BITS) - IEEE754_EXPN_BIAS; - - mant.f -= 1.0f; - - // polynomial for log2(1+x) over x=[0,1] - //x = (-0.346555386f * mant.f + 1.346555386f) * mant.f; - x = (((-0.0821307180f * mant.f + 0.321188984f) * mant.f - 0.677784014f) * mant.f + 1.43872575f) * mant.f; - - return x + expn; -} - -// -// for -126 <= x < 128, returns exp2(x) -// -// rel |error| < 3e-3, smooth (exact for x=N) for NPOLY=3 -// rel |error| < 9e-6, smooth (exact for x=N) for NPOLY=5 -// -static inline float fastexp2(float x) { - - union { float f; int32_t i; } xi; - - // bias such that x > 0 - x += IEEE754_EXPN_BIAS; - //x = MAX(x, 1.0f); - //x = MIN(x, 254.9999f); - - // split into integer and fraction - xi.i = (int32_t)x; - x -= xi.i; - - // construct exp2(xi) as a float - xi.i <<= IEEE754_MANT_BITS; - - // polynomial for exp2(x) over x=[0,1] - //x = (0.339766028f * x + 0.660233972f) * x + 1.0f; - x = (((0.0135557472f * x + 0.0520323690f) * x + 0.241379763f) * x + 0.693032121f) * x + 1.0f; - - return x * xi.f; -} - float AudioMixerSlave::gainForSource(const AvatarAudioStream& listeningNodeStream, const PositionalAudioStream& streamToAdd, const glm::vec3& relativePosition, bool isEcho) { float gain = 1.0f; @@ -514,7 +458,7 @@ float AudioMixerSlave::gainForSource(const AvatarAudioStream& listeningNodeStrea g = (g > 1.0f) ? 1.0f : g; // calculate the distance coefficient using the distance to this node - float distanceCoefficient = fastexp2(fastlog2(g) * fastlog2(distanceBetween/ATTENUATION_BEGINS_AT_DISTANCE)); + float distanceCoefficient = fastExp2f(fastLog2f(g) * fastLog2f(distanceBetween/ATTENUATION_BEGINS_AT_DISTANCE)); // multiply the current attenuation coefficient by the distance coefficient gain *= distanceCoefficient;