From 698eddbb0caf6ba77d644e7de5da01ad6687ee68 Mon Sep 17 00:00:00 2001 From: Chris Robinson Date: Thu, 6 Oct 2016 20:05:16 -0700 Subject: Better sort the main delay line taps --- Alc/effects/reverb.c | 99 +++++++++++++++++++++------------------------------- 1 file changed, 39 insertions(+), 60 deletions(-) (limited to 'Alc/effects/reverb.c') diff --git a/Alc/effects/reverb.c b/Alc/effects/reverb.c index 7dfa37d1..d8dd14f3 100644 --- a/Alc/effects/reverb.c +++ b/Alc/effects/reverb.c @@ -90,15 +90,11 @@ typedef struct ALreverbState { /* Core delay line (early reflections and late reverb tap from this). */ DelayLine Delay; - /* The tap points for the initial delay. First tap goes to early + /* The tap points for the initial delay. First set go to early * reflections, second to late reverb. */ - ALuint DelayTap[2]; - /* There are actually 4 decorrelator taps, but the first occurs at the late - * reverb tap. - */ - ALuint EarlyDecoTap[3]; - ALuint LateDecoTap[3]; + ALuint EarlyDelayTap[4]; + ALuint LateDelayTap[4]; struct { // Early reflections are done with 4 delay lines. @@ -221,14 +217,10 @@ static void ALreverbState_Construct(ALreverbState *state) state->Delay.Mask = 0; state->Delay.Line = NULL; - state->DelayTap[0] = 0; - state->DelayTap[1] = 0; - state->EarlyDecoTap[0] = 0; - state->EarlyDecoTap[1] = 0; - state->EarlyDecoTap[2] = 0; - state->LateDecoTap[0] = 0; - state->LateDecoTap[1] = 0; - state->LateDecoTap[2] = 0; + for(index = 0;index < 4;index++) + state->EarlyDelayTap[index] = 0; + for(index = 0;index < 4;index++) + state->LateDelayTap[index] = 0; for(index = 0;index < 4;index++) { @@ -330,7 +322,7 @@ static const ALfloat ECHO_ALLPASS_LENGTH = 0.0133f; /* Input into the early reflections and late reverb are decorrelated between * four channels. Their timings are dependent on a fraction and multiplier. See - * the UpdateDecorrelator() routine for the calculations involved. + * the UpdateDelayLine() routine for the calculations involved. */ static const ALfloat DECO_FRACTION = 0.15f; static const ALfloat DECO_MULTIPLIER = 2.0f; @@ -669,12 +661,27 @@ static ALvoid UpdateModulator(ALfloat modTime, ALfloat modDepth, ALuint frequenc 2.0f * frequency; } -// Update the offsets for the initial effect delay line. -static ALvoid UpdateDelayLine(ALfloat earlyDelay, ALfloat lateDelay, ALuint frequency, ALreverbState *State) +// Update the offsets for the main effect delay line. +static ALvoid UpdateDelayLine(ALfloat earlyDelay, ALfloat lateDelay, ALfloat density, ALuint frequency, ALreverbState *State) { - // Calculate the initial delay taps. - State->DelayTap[0] = fastf2u(earlyDelay * frequency); - State->DelayTap[1] = fastf2u((earlyDelay + lateDelay) * frequency); + ALfloat length; + ALuint i; + + State->EarlyDelayTap[0] = fastf2u(earlyDelay * frequency); + for(i = 1;i < 4;i++) + { + length = (DECO_FRACTION * powf(DECO_MULTIPLIER, (ALfloat)i-1.0f)) * + EARLY_LINE_LENGTH[0]; + State->EarlyDelayTap[i] = fastf2u(length * frequency) + State->EarlyDelayTap[0]; + } + + State->LateDelayTap[0] = fastf2u((earlyDelay + lateDelay) * frequency); + for(i = 1;i < 4;i++) + { + length = (DECO_FRACTION * powf(DECO_MULTIPLIER, (ALfloat)i-1.0f)) * + LATE_LINE_LENGTH[0] * (1.0f + (density * LATE_LINE_MULTIPLIER)); + State->LateDelayTap[i] = fastf2u(length * frequency) + State->LateDelayTap[0]; + } } // Update the early reflections mix and line coefficients. @@ -690,31 +697,6 @@ static ALvoid UpdateEarlyLines(ALfloat lateDelay, ALreverbState *State) lateDelay); } -// Update the offsets for the decorrelator line. -static ALvoid UpdateDecorrelator(ALfloat density, ALuint frequency, ALreverbState *State) -{ - ALuint index; - ALfloat length; - - /* The early reflections and late reverb inputs are decorrelated to provide - * time-varying reflections, smooth out the reverb tail, and reduce harsh - * echos. The first tap occurs immediately, while the remaining taps are - * delayed by multiples of a fraction of the smallest cyclical delay time. - * - * offset[index] = (FRACTION (MULTIPLIER^index)) smallest_delay - */ - for(index = 0;index < 3;index++) - { - length = (DECO_FRACTION * powf(DECO_MULTIPLIER, (ALfloat)index)) * - EARLY_LINE_LENGTH[0]; - State->EarlyDecoTap[index] = fastf2u(length * frequency) + State->DelayTap[0]; - - length = (DECO_FRACTION * powf(DECO_MULTIPLIER, (ALfloat)index)) * - LATE_LINE_LENGTH[0] * (1.0f + (density * LATE_LINE_MULTIPLIER)); - State->LateDecoTap[index] = fastf2u(length * frequency) + State->DelayTap[1]; - } -} - // Update the late reverb mix, line lengths, and line coefficients. static ALvoid UpdateLateLines(ALfloat xMix, ALfloat density, ALfloat decayTime, ALfloat diffusion, ALfloat echoDepth, ALfloat hfRatio, ALfloat cw, ALuint frequency, ALreverbState *State) { @@ -975,12 +957,9 @@ static ALvoid ALreverbState_update(ALreverbState *State, const ALCdevice *Device UpdateModulator(props->Reverb.ModulationTime, props->Reverb.ModulationDepth, frequency, State); - // Update the initial effect delay. + // Update the main effect delay. UpdateDelayLine(props->Reverb.ReflectionsDelay, props->Reverb.LateReverbDelay, - frequency, State); - - // Update the decorrelator. - UpdateDecorrelator(props->Reverb.Density, frequency, State); + props->Reverb.Density, frequency, State); // Update the early lines. UpdateEarlyLines(props->Reverb.LateReverbDelay, State); @@ -1112,10 +1091,10 @@ static ALvoid EarlyReflection(ALreverbState *State, ALuint todo, ALfloat (*restr ALuint offset = State->Offset+i; /* Obtain the first reflection samples from the main delay line. */ - f[0] = DelayLineOut(&State->Delay, (offset-State->DelayTap[0])*4 + 0); - f[1] = DelayLineOut(&State->Delay, (offset-State->EarlyDecoTap[0])*4 + 1); - f[2] = DelayLineOut(&State->Delay, (offset-State->EarlyDecoTap[1])*4 + 2); - f[3] = DelayLineOut(&State->Delay, (offset-State->EarlyDecoTap[2])*4 + 3); + f[0] = DelayLineOut(&State->Delay, (offset-State->EarlyDelayTap[0])*4 + 0); + f[1] = DelayLineOut(&State->Delay, (offset-State->EarlyDelayTap[1])*4 + 1); + f[2] = DelayLineOut(&State->Delay, (offset-State->EarlyDelayTap[2])*4 + 2); + f[3] = DelayLineOut(&State->Delay, (offset-State->EarlyDelayTap[3])*4 + 3); /* The following uses a lossless scattering junction from waveguide * theory. It actually amounts to a householder mixing matrix, which @@ -1201,10 +1180,10 @@ static ALvoid LateReverb(ALreverbState *State, ALuint todo, ALfloat (*restrict o for(i = 0;i < tmp_todo;i++) { /* Obtain four decorrelated input samples. */ - f[0] = DelayLineOut(&State->Delay, (offset-State->DelayTap[1])*4 + 0) * State->Late.DensityGain; - f[1] = DelayLineOut(&State->Delay, (offset-State->LateDecoTap[0])*4 + 1) * State->Late.DensityGain; - f[2] = DelayLineOut(&State->Delay, (offset-State->LateDecoTap[1])*4 + 2) * State->Late.DensityGain; - f[3] = DelayLineOut(&State->Delay, (offset-State->LateDecoTap[2])*4 + 3) * State->Late.DensityGain; + f[0] = DelayLineOut(&State->Delay, (offset-State->LateDelayTap[0])*4 + 0) * State->Late.DensityGain; + f[1] = DelayLineOut(&State->Delay, (offset-State->LateDelayTap[1])*4 + 1) * State->Late.DensityGain; + f[2] = DelayLineOut(&State->Delay, (offset-State->LateDelayTap[2])*4 + 2) * State->Late.DensityGain; + f[3] = DelayLineOut(&State->Delay, (offset-State->LateDelayTap[3])*4 + 3) * State->Late.DensityGain; /* Add the decayed results of the cyclical delay lines, then pass * the results through the low-pass filters. @@ -1313,7 +1292,7 @@ static ALvoid EAXEcho(ALreverbState *State, ALuint todo, ALfloat (*restrict late // Mix the energy-attenuated input with the output and pass it through // the echo low-pass filter. - feed += DelayLineOut(&State->Delay, (offset-State->DelayTap[1])*4 + c) * + feed += DelayLineOut(&State->Delay, (offset-State->LateDelayTap[0])*4 + c) * State->Echo.DensityGain; feed = lerp(feed, State->Echo.LpSample[c], State->Echo.LpCoeff); State->Echo.LpSample[c] = feed; -- cgit v1.2.3