diff options
Diffstat (limited to 'Alc/ALu.c')
| -rw-r--r-- | Alc/ALu.c | 43 |
1 files changed, 39 insertions, 4 deletions
@@ -137,6 +137,42 @@ static inline ALvoid aluMatrixVector(ALfloat *vector, ALfloat w, ALfloat (*restr } +/* Calculates the fade time from the changes in gain and listener to source + * angle between updates. The result is a the time, in seconds, for the + * transition to complete. + */ +static ALfloat CalcFadeTime(ALfloat oldGain, ALfloat newGain, const ALfloat olddir[3], const ALfloat newdir[3]) +{ + ALfloat gainChange, angleChange, change; + + /* Calculate the normalized dB gain change. */ + newGain = maxf(newGain, 0.0001f); + oldGain = maxf(oldGain, 0.0001f); + gainChange = fabsf(log10f(newGain / oldGain) / log10f(0.0001f)); + + /* Calculate the angle change only when there is enough gain to notice it. */ + angleChange = 0.0f; + if(gainChange > 0.0001f || newGain > 0.0001f) + { + /* No angle change when the directions are equal or degenerate (when + * both have zero length). + */ + if(newdir[0] != olddir[0] || newdir[1] != olddir[1] || newdir[2] != olddir[2]) + { + ALfloat dotp = aluDotproduct(olddir, newdir); + angleChange = acosf(clampf(dotp, -1.0f, 1.0f)) / F_PI; + } + } + + /* Use the largest of the two changes, and apply a significance shaping + * function to it. The result is then scaled to cover a 15ms transition + * range. + */ + change = maxf(angleChange * 25.0f, gainChange) * 2.0f; + return minf(change, 1.0f) * 0.015f; +} + + static void UpdateDryStepping(DirectParams *params, ALuint num_chans) { ALuint i, j; @@ -997,12 +1033,11 @@ ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALCconte /* Check to see if the HRIR is already moving. */ if(voice->Direct.Moving) { - /* Calculate the normalized HRTF transition factor (delta). */ - delta = CalcHrtfDelta(voice->Direct.LastGain, DryGain, - voice->Direct.LastDir, Position); + delta = CalcFadeTime(voice->Direct.LastGain, DryGain, + voice->Direct.LastDir, Position); /* If the delta is large enough, get the moving HRIR target * coefficients, target delays, steppping values, and counter. */ - if(delta > 0.001f) + if(delta > 0.000015f) { ALuint counter = GetMovingHrtfCoeffs(Device->Hrtf, ev, az, dirfact, DryGain, delta, voice->Direct.Counter, |