/**
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
* Or go to http://www.gnu.org/copyleft/lgpl.html
*/
#include "config.h"
#include <math.h>
#include <stdlib.h>
#include "alMain.h"
#include "alFilter.h"
#include "alAuxEffectSlot.h"
#include "alError.h"
#include "alu.h"
typedef struct ALechoState {
DERIVE_FROM_TYPE(ALeffectState);
ALfloat *SampleBuffer;
ALuint BufferLength;
// The echo is two tap. The delay is the number of samples from before the
// current offset
struct {
ALuint delay;
} Tap[2];
ALuint Offset;
/* The panning gains for the two taps */
ALfloat Gain[2][MaxChannels];
ALfloat FeedGain;
ALfilterState Filter;
} ALechoState;
static ALvoid ALechoState_Destruct(ALechoState *state)
{
free(state->SampleBuffer);
state->SampleBuffer = NULL;
}
static ALboolean ALechoState_deviceUpdate(ALechoState *state, ALCdevice *Device)
{
ALuint maxlen, i;
// 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 = fastf2u(AL_ECHO_MAX_DELAY * Device->Frequency) + 1;
maxlen += fastf2u(AL_ECHO_MAX_LRDELAY * Device->Frequency) + 1;
maxlen = NextPowerOf2(maxlen);
if(maxlen != state->BufferLength)
{
void *temp;
temp = realloc(state->SampleBuffer, maxlen * sizeof(ALfloat));
if(!temp) return AL_FALSE;
state->SampleBuffer = temp;
state->BufferLength = maxlen;
}
for(i = 0;i < state->BufferLength;i++)
state->SampleBuffer[i] = 0.0f;
return AL_TRUE;
}
static ALvoid ALechoState_update(ALechoState *state, ALCdevice *Device, const ALeffectslot *Slot)
{
ALuint frequency = Device->Frequency;
ALfloat lrpan, gain;
ALfloat dirGain;
state->Tap[0].delay = fastf2u(Slot->EffectProps.Echo.Delay * frequency) + 1;
state->Tap[1].delay = fastf2u(Slot->EffectProps.Echo.LRDelay * frequency);
state->Tap[1].delay += state->Tap[0].delay;
lrpan = Slot->EffectProps.Echo.Spread;
state->FeedGain = Slot->EffectProps.Echo.Feedback;
ALfilterState_setParams(&state->Filter, ALfilterType_HighShelf,
1.0f - Slot->EffectProps.Echo.Damping,
LOWPASSFREQREF/frequency, 0.0f);
gain = Slot->Gain;
dirGain = fabsf(lrpan);
/* First tap panning */
ComputeAngleGains(Device, atan2f(-lrpan, 0.0f), (1.0f-dirGain)*F_PI, gain, state->Gain[0]);
/* Second tap panning */
ComputeAngleGains(Device, atan2f(+lrpan, 0.0f), (1.0f-dirGain)*F_PI, gain, state->Gain[1]);
}
static ALvoid ALechoState_process(ALechoState *state, ALuint SamplesToDo, const ALfloat *restrict SamplesIn, ALfloat (*restrict SamplesOut)[BUFFERSIZE])
{
const ALuint mask = state->BufferLength-1;
const ALuint tap1 = state->Tap[0].delay;
const ALuint tap2 = state->Tap[1].delay;
ALuint offset = state->Offset;
ALfloat smp;
ALuint base;
ALuint i, k;
for(base = 0;base < SamplesToDo;)
{
ALfloat temps[64][2];
ALuint td = minu(SamplesToDo-base, 64);
for(i = 0;i < td;i++)
{
/* First tap */
temps[i][0] = state->SampleBuffer[(offset-tap1) & mask];
/* Second tap */
temps[i][1] = state->SampleBuffer[(offset-tap2) & mask];
// Apply damping and feedback gain to the second tap, and mix in the
// new sample
smp = ALfilterState_processSingle(&state->Filter, temps[i][1]+SamplesIn[i+base]);
state->SampleBuffer[offset&mask] = smp * state->FeedGain;
offset++;
}
for(k = 0;k < MaxChannels;k++)
{
ALfloat gain = state->Gain[0][k];
if(gain > GAIN_SILENCE_THRESHOLD)
{
for(i = 0;i < td;i++)
SamplesOut[k][i+base] += temps[i][0] * gain;
}
gain = state->Gain[1][k];
if(gain > GAIN_SILENCE_THRESHOLD)
{
for(i = 0;i < td;i++)
SamplesOut[k][i+base] += temps[i][1] * gain;
}
}
base += td;
}
state->Offset = offset;
}
DECLARE_DEFAULT_ALLOCATORS(ALechoState)
DEFINE_ALEFFECTSTATE_VTABLE(ALechoState);
typedef struct ALechoStateFactory {
DERIVE_FROM_TYPE(ALeffectStateFactory);
} ALechoStateFactory;
ALeffectState *ALechoStateFactory_create(ALechoStateFactory *UNUSED(factory))
{
ALechoState *state;
state = ALechoState_New(sizeof(*state));
if(!state) return NULL;
SET_VTABLE2(ALechoState, ALeffectState, state);
state->BufferLength = 0;
state->SampleBuffer = NULL;
state->Tap[0].delay = 0;
state->Tap[1].delay = 0;
state->Offset = 0;
ALfilterState_clear(&state->Filter);
return STATIC_CAST(ALeffectState, state);
}
DEFINE_ALEFFECTSTATEFACTORY_VTABLE(ALechoStateFactory);
ALeffectStateFactory *ALechoStateFactory_getFactory(void)
{
static ALechoStateFactory EchoFactory = { { GET_VTABLE2(ALechoStateFactory, ALeffectStateFactory) } };
return STATIC_CAST(ALeffectStateFactory, &EchoFactory);
}
void ALecho_setParami(ALeffect *UNUSED(effect), ALCcontext *context, ALenum UNUSED(param), ALint UNUSED(val))
{ SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); }
void ALecho_setParamiv(ALeffect *effect, ALCcontext *context, ALenum param, const ALint *vals)
{
ALecho_setParami(effect, context, param, vals[0]);
}
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))
SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
props->Echo.Delay = val;
break;
case AL_ECHO_LRDELAY:
if(!(val >= AL_ECHO_MIN_LRDELAY && val <= AL_ECHO_MAX_LRDELAY))
SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
props->Echo.LRDelay = val;
break;
case AL_ECHO_DAMPING:
if(!(val >= AL_ECHO_MIN_DAMPING && val <= AL_ECHO_MAX_DAMPING))
SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
props->Echo.Damping = val;
break;
case AL_ECHO_FEEDBACK:
if(!(val >= AL_ECHO_MIN_FEEDBACK && val <= AL_ECHO_MAX_FEEDBACK))
SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
props->Echo.Feedback = val;
break;
case AL_ECHO_SPREAD:
if(!(val >= AL_ECHO_MIN_SPREAD && val <= AL_ECHO_MAX_SPREAD))
SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
props->Echo.Spread = val;
break;
default:
SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
}
}
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 UNUSED(param), ALint *UNUSED(val))
{ SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); }
void ALecho_getParamiv(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *vals)
{
ALecho_getParami(effect, context, param, vals);
}
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:
SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
}
}
void ALecho_getParamfv(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals)
{
ALecho_getParamf(effect, context, param, vals);
}
DEFINE_ALEFFECT_VTABLE(ALecho);