AuroraOpenALSoft/Alc/alcModulator.c
2013-05-21 04:18:02 -07:00

313 lines
11 KiB
C

/**
* 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 ALmodulatorState {
DERIVE_FROM_TYPE(ALeffectState);
enum {
SINUSOID,
SAWTOOTH,
SQUARE
} Waveform;
ALuint index;
ALuint step;
ALfloat Gain[MaxChannels];
FILTER iirFilter;
ALfloat history[1];
} ALmodulatorState;
#define WAVEFORM_FRACBITS 24
#define WAVEFORM_FRACONE (1<<WAVEFORM_FRACBITS)
#define WAVEFORM_FRACMASK (WAVEFORM_FRACONE-1)
static __inline ALfloat Sin(ALuint index)
{
return sinf(index * (F_PI*2.0f / WAVEFORM_FRACONE) - F_PI)*0.5f + 0.5f;
}
static __inline ALfloat Saw(ALuint index)
{
return (ALfloat)index / WAVEFORM_FRACONE;
}
static __inline ALfloat Square(ALuint index)
{
return (ALfloat)((index >> (WAVEFORM_FRACBITS - 1)) & 1);
}
static __inline ALfloat hpFilter1P(FILTER *iir, ALuint offset, ALfloat input)
{
ALfloat *history = &iir->history[offset];
ALfloat a = iir->coeff;
ALfloat output = input;
output = output + (history[0]-output)*a;
history[0] = output;
return input - output;
}
#define DECL_TEMPLATE(func) \
static void Process##func(ALmodulatorState *state, ALuint SamplesToDo, \
const ALfloat *RESTRICT SamplesIn, \
ALfloat (*RESTRICT SamplesOut)[BUFFERSIZE]) \
{ \
const ALuint step = state->step; \
ALuint index = state->index; \
ALuint base; \
\
for(base = 0;base < SamplesToDo;) \
{ \
ALfloat temps[64]; \
ALuint td = minu(SamplesToDo-base, 64); \
ALuint i, k; \
\
for(i = 0;i < td;i++) \
{ \
ALfloat samp; \
samp = SamplesIn[base+i]; \
samp = hpFilter1P(&state->iirFilter, 0, samp); \
\
index += step; \
index &= WAVEFORM_FRACMASK; \
temps[i] = samp * func(index); \
} \
\
for(k = 0;k < MaxChannels;k++) \
{ \
ALfloat gain = state->Gain[k]; \
if(!(gain > 0.00001f)) \
continue; \
\
for(i = 0;i < td;i++) \
SamplesOut[k][base+i] += gain * temps[i]; \
} \
\
base += td; \
} \
state->index = index; \
}
DECL_TEMPLATE(Sin)
DECL_TEMPLATE(Saw)
DECL_TEMPLATE(Square)
#undef DECL_TEMPLATE
static ALvoid ALmodulatorState_Destroy(ALeffectState *effect)
{
ALmodulatorState *state = STATIC_UPCAST(ALmodulatorState, ALeffectState, effect);
free(state);
}
static ALboolean ALmodulatorState_DeviceUpdate(ALeffectState *effect, ALCdevice *Device)
{
return AL_TRUE;
(void)effect;
(void)Device;
}
static ALvoid ALmodulatorState_Update(ALeffectState *effect, ALCdevice *Device, const ALeffectslot *Slot)
{
ALmodulatorState *state = STATIC_UPCAST(ALmodulatorState, ALeffectState, effect);
ALfloat gain, cw, a = 0.0f;
ALuint index;
if(Slot->effect.Modulator.Waveform == AL_RING_MODULATOR_SINUSOID)
state->Waveform = SINUSOID;
else if(Slot->effect.Modulator.Waveform == AL_RING_MODULATOR_SAWTOOTH)
state->Waveform = SAWTOOTH;
else if(Slot->effect.Modulator.Waveform == AL_RING_MODULATOR_SQUARE)
state->Waveform = SQUARE;
state->step = fastf2u(Slot->effect.Modulator.Frequency*WAVEFORM_FRACONE /
Device->Frequency);
if(state->step == 0) state->step = 1;
cw = cosf(F_PI*2.0f * Slot->effect.Modulator.HighPassCutoff /
Device->Frequency);
a = (2.0f-cw) - sqrtf(powf(2.0f-cw, 2.0f) - 1.0f);
state->iirFilter.coeff = a;
gain = sqrtf(1.0f/Device->NumChan);
gain *= Slot->Gain;
for(index = 0;index < MaxChannels;index++)
state->Gain[index] = 0.0f;
for(index = 0;index < Device->NumChan;index++)
{
enum Channel chan = Device->Speaker2Chan[index];
state->Gain[chan] = gain;
}
}
static ALvoid ALmodulatorState_Process(ALeffectState *effect, ALuint SamplesToDo, const ALfloat *RESTRICT SamplesIn, ALfloat (*RESTRICT SamplesOut)[BUFFERSIZE])
{
ALmodulatorState *state = STATIC_UPCAST(ALmodulatorState, ALeffectState, effect);
switch(state->Waveform)
{
case SINUSOID:
ProcessSin(state, SamplesToDo, SamplesIn, SamplesOut);
break;
case SAWTOOTH:
ProcessSaw(state, SamplesToDo, SamplesIn, SamplesOut);
break;
case SQUARE:
ProcessSquare(state, SamplesToDo, SamplesIn, SamplesOut);
break;
}
}
DEFINE_ALEFFECTSTATE_VTABLE(ALmodulatorState);
ALeffectState *ModulatorCreate(void)
{
ALmodulatorState *state;
state = malloc(sizeof(*state));
if(!state) return NULL;
SET_VTABLE2(ALmodulatorState, ALeffectState, state);
state->index = 0;
state->step = 1;
state->iirFilter.coeff = 0.0f;
state->iirFilter.history[0] = 0.0f;
return STATIC_CAST(ALeffectState, state);
}
void mod_SetParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat val)
{
switch(param)
{
case AL_RING_MODULATOR_FREQUENCY:
if(val >= AL_RING_MODULATOR_MIN_FREQUENCY && val <= AL_RING_MODULATOR_MAX_FREQUENCY)
effect->Modulator.Frequency = val;
else
alSetError(context, AL_INVALID_VALUE);
break;
case AL_RING_MODULATOR_HIGHPASS_CUTOFF:
if(val >= AL_RING_MODULATOR_MIN_HIGHPASS_CUTOFF && val <= AL_RING_MODULATOR_MAX_HIGHPASS_CUTOFF)
effect->Modulator.HighPassCutoff = val;
else
alSetError(context, AL_INVALID_VALUE);
break;
default:
alSetError(context, AL_INVALID_ENUM);
break;
}
}
void mod_SetParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals)
{
mod_SetParamf(effect, context, param, vals[0]);
}
void mod_SetParami(ALeffect *effect, ALCcontext *context, ALenum param, ALint val)
{
switch(param)
{
case AL_RING_MODULATOR_FREQUENCY:
case AL_RING_MODULATOR_HIGHPASS_CUTOFF:
mod_SetParamf(effect, context, param, (ALfloat)val);
break;
case AL_RING_MODULATOR_WAVEFORM:
if(val >= AL_RING_MODULATOR_MIN_WAVEFORM && val <= AL_RING_MODULATOR_MAX_WAVEFORM)
effect->Modulator.Waveform = val;
else
alSetError(context, AL_INVALID_VALUE);
break;
default:
alSetError(context, AL_INVALID_ENUM);
break;
}
}
void mod_SetParamiv(ALeffect *effect, ALCcontext *context, ALenum param, const ALint *vals)
{
mod_SetParami(effect, context, param, vals[0]);
}
void mod_GetParami(ALeffect *effect, ALCcontext *context, ALenum param, ALint *val)
{
switch(param)
{
case AL_RING_MODULATOR_FREQUENCY:
*val = (ALint)effect->Modulator.Frequency;
break;
case AL_RING_MODULATOR_HIGHPASS_CUTOFF:
*val = (ALint)effect->Modulator.HighPassCutoff;
break;
case AL_RING_MODULATOR_WAVEFORM:
*val = effect->Modulator.Waveform;
break;
default:
alSetError(context, AL_INVALID_ENUM);
break;
}
}
void mod_GetParamiv(ALeffect *effect, ALCcontext *context, ALenum param, ALint *vals)
{
mod_GetParami(effect, context, param, vals);
}
void mod_GetParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *val)
{
switch(param)
{
case AL_RING_MODULATOR_FREQUENCY:
*val = effect->Modulator.Frequency;
break;
case AL_RING_MODULATOR_HIGHPASS_CUTOFF:
*val = effect->Modulator.HighPassCutoff;
break;
default:
alSetError(context, AL_INVALID_ENUM);
break;
}
}
void mod_GetParamfv(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals)
{
mod_GetParamf(effect, context, param, vals);
}