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/**
* OpenAL cross platform audio library
* Copyright (C) 2009 by Chris Robinson.
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
* Or go to http://www.gnu.org/copyleft/lgpl.html
*/
#include "config.h"
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include "alMain.h"
#include "alcontext.h"
#include "alFilter.h"
#include "alAuxEffectSlot.h"
#include "alError.h"
#include "alu.h"
#include "filters/biquad.h"
#include "vector.h"
struct ALechoState final : public EffectState {
al::vector<ALfloat,16> mSampleBuffer;
// The echo is two tap. The delay is the number of samples from before the
// current offset
struct {
ALsizei delay{0};
} mTap[2];
ALsizei mOffset{0};
/* The panning gains for the two taps */
struct {
ALfloat Current[MAX_OUTPUT_CHANNELS]{};
ALfloat Target[MAX_OUTPUT_CHANNELS]{};
} mGains[2];
ALfloat mFeedGain{0.0f};
BiquadFilter mFilter;
ALboolean deviceUpdate(const ALCdevice *device) override;
void update(const ALCcontext *context, const ALeffectslot *slot, const ALeffectProps *props, const EffectTarget target) override;
void process(ALsizei samplesToDo, const ALfloat (*RESTRICT samplesIn)[BUFFERSIZE], ALfloat (*RESTRICT samplesOut)[BUFFERSIZE], ALsizei numChannels) override;
DEF_NEWDEL(ALechoState)
};
ALboolean ALechoState::deviceUpdate(const ALCdevice *Device)
{
ALuint maxlen;
// Use the next power of 2 for the buffer length, so the tap offsets can be
// wrapped using a mask instead of a modulo
maxlen = float2int(AL_ECHO_MAX_DELAY*Device->Frequency + 0.5f) +
float2int(AL_ECHO_MAX_LRDELAY*Device->Frequency + 0.5f);
maxlen = NextPowerOf2(maxlen);
if(maxlen <= 0) return AL_FALSE;
if(maxlen != mSampleBuffer.size())
{
mSampleBuffer.resize(maxlen);
mSampleBuffer.shrink_to_fit();
}
std::fill(mSampleBuffer.begin(), mSampleBuffer.end(), 0.0f);
for(auto &e : mGains)
{
std::fill(std::begin(e.Current), std::end(e.Current), 0.0f);
std::fill(std::begin(e.Target), std::end(e.Target), 0.0f);
}
return AL_TRUE;
}
void ALechoState::update(const ALCcontext *context, const ALeffectslot *slot, const ALeffectProps *props, const EffectTarget target)
{
const ALCdevice *device = context->Device;
ALuint frequency = device->Frequency;
ALfloat gainhf, lrpan, spread;
mTap[0].delay = maxi(float2int(props->Echo.Delay*frequency + 0.5f), 1);
mTap[1].delay = float2int(props->Echo.LRDelay*frequency + 0.5f);
mTap[1].delay += mTap[0].delay;
spread = props->Echo.Spread;
if(spread < 0.0f) lrpan = -1.0f;
else lrpan = 1.0f;
/* Convert echo spread (where 0 = omni, +/-1 = directional) to coverage
* spread (where 0 = point, tau = omni).
*/
spread = asinf(1.0f - fabsf(spread))*4.0f;
mFeedGain = props->Echo.Feedback;
gainhf = maxf(1.0f - props->Echo.Damping, 0.0625f); /* Limit -24dB */
mFilter.setParams(BiquadType::HighShelf, gainhf, LOWPASSFREQREF/frequency,
calc_rcpQ_from_slope(gainhf, 1.0f)
);
ALfloat coeffs[2][MAX_AMBI_COEFFS];
CalcAngleCoeffs(al::MathDefs<float>::Pi()*-0.5f*lrpan, 0.0f, spread, coeffs[0]);
CalcAngleCoeffs(al::MathDefs<float>::Pi()* 0.5f*lrpan, 0.0f, spread, coeffs[1]);
mOutBuffer = target.Main->Buffer;
mOutChannels = target.Main->NumChannels;
ComputePanGains(target.Main, coeffs[0], slot->Params.Gain, mGains[0].Target);
ComputePanGains(target.Main, coeffs[1], slot->Params.Gain, mGains[1].Target);
}
void ALechoState::process(ALsizei SamplesToDo, const ALfloat (*RESTRICT SamplesIn)[BUFFERSIZE], ALfloat (*RESTRICT SamplesOut)[BUFFERSIZE], ALsizei NumChannels)
{
const auto mask = static_cast<ALsizei>(mSampleBuffer.size()-1);
const ALsizei tap1{mTap[0].delay};
const ALsizei tap2{mTap[1].delay};
ALfloat *RESTRICT delaybuf{mSampleBuffer.data()};
ALsizei offset{mOffset};
ALfloat z1, z2;
ALsizei base;
ALsizei c, i;
std::tie(z1, z2) = mFilter.getComponents();
for(base = 0;base < SamplesToDo;)
{
alignas(16) ALfloat temps[2][128];
ALsizei td = mini(128, SamplesToDo-base);
for(i = 0;i < td;i++)
{
/* Feed the delay buffer's input first. */
delaybuf[offset&mask] = SamplesIn[0][i+base];
/* First tap */
temps[0][i] = delaybuf[(offset-tap1) & mask];
/* Second tap */
temps[1][i] = delaybuf[(offset-tap2) & mask];
/* Apply damping to the second tap, then add it to the buffer with
* feedback attenuation.
*/
float out{mFilter.processOne(temps[1][i], z1, z2)};
delaybuf[offset&mask] += out * mFeedGain;
offset++;
}
for(c = 0;c < 2;c++)
MixSamples(temps[c], NumChannels, SamplesOut, mGains[c].Current,
mGains[c].Target, SamplesToDo-base, base, td);
base += td;
}
mFilter.setComponents(z1, z2);
mOffset = offset;
}
struct EchoStateFactory final : public EffectStateFactory {
EffectState *create() override;
};
EffectState *EchoStateFactory::create()
{ return new ALechoState{}; }
EffectStateFactory *EchoStateFactory_getFactory(void)
{
static EchoStateFactory EchoFactory{};
return &EchoFactory;
}
void ALecho_setParami(ALeffect *UNUSED(effect), ALCcontext *context, ALenum param, ALint UNUSED(val))
{ alSetError(context, AL_INVALID_ENUM, "Invalid echo integer property 0x%04x", param); }
void ALecho_setParamiv(ALeffect *UNUSED(effect), ALCcontext *context, ALenum param, const ALint *UNUSED(vals))
{ alSetError(context, AL_INVALID_ENUM, "Invalid echo integer-vector property 0x%04x", param); }
void ALecho_setParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat val)
{
ALeffectProps *props = &effect->Props;
switch(param)
{
case AL_ECHO_DELAY:
if(!(val >= AL_ECHO_MIN_DELAY && val <= AL_ECHO_MAX_DELAY))
SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo delay out of range");
props->Echo.Delay = val;
break;
case AL_ECHO_LRDELAY:
if(!(val >= AL_ECHO_MIN_LRDELAY && val <= AL_ECHO_MAX_LRDELAY))
SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo LR delay out of range");
props->Echo.LRDelay = val;
break;
case AL_ECHO_DAMPING:
if(!(val >= AL_ECHO_MIN_DAMPING && val <= AL_ECHO_MAX_DAMPING))
SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo damping out of range");
props->Echo.Damping = val;
break;
case AL_ECHO_FEEDBACK:
if(!(val >= AL_ECHO_MIN_FEEDBACK && val <= AL_ECHO_MAX_FEEDBACK))
SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo feedback out of range");
props->Echo.Feedback = val;
break;
case AL_ECHO_SPREAD:
if(!(val >= AL_ECHO_MIN_SPREAD && val <= AL_ECHO_MAX_SPREAD))
SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo spread out of range");
props->Echo.Spread = val;
break;
default:
alSetError(context, AL_INVALID_ENUM, "Invalid echo float property 0x%04x", param);
}
}
void ALecho_setParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals)
{ ALecho_setParamf(effect, context, param, vals[0]); }
void ALecho_getParami(const ALeffect *UNUSED(effect), ALCcontext *context, ALenum param, ALint *UNUSED(val))
{ alSetError(context, AL_INVALID_ENUM, "Invalid echo integer property 0x%04x", param); }
void ALecho_getParamiv(const ALeffect *UNUSED(effect), ALCcontext *context, ALenum param, ALint *UNUSED(vals))
{ alSetError(context, AL_INVALID_ENUM, "Invalid echo integer-vector property 0x%04x", param); }
void ALecho_getParamf(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *val)
{
const ALeffectProps *props = &effect->Props;
switch(param)
{
case AL_ECHO_DELAY:
*val = props->Echo.Delay;
break;
case AL_ECHO_LRDELAY:
*val = props->Echo.LRDelay;
break;
case AL_ECHO_DAMPING:
*val = props->Echo.Damping;
break;
case AL_ECHO_FEEDBACK:
*val = props->Echo.Feedback;
break;
case AL_ECHO_SPREAD:
*val = props->Echo.Spread;
break;
default:
alSetError(context, AL_INVALID_ENUM, "Invalid echo float property 0x%04x", param);
}
}
void ALecho_getParamfv(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals)
{ ALecho_getParamf(effect, context, param, vals); }
DEFINE_ALEFFECT_VTABLE(ALecho);
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