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Diffstat (limited to 'Alc/effects/flanger.c')
| -rw-r--r-- | Alc/effects/flanger.c | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/Alc/effects/flanger.c b/Alc/effects/flanger.c new file mode 100644 index 00000000..a94cd365 --- /dev/null +++ b/Alc/effects/flanger.c @@ -0,0 +1,380 @@ +/** + * OpenAL cross platform audio library + * Copyright (C) 2013 by Mike Gorchak + * 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 ALflangerState { + DERIVE_FROM_TYPE(ALeffectState); + + ALfloat *SampleBuffer[2]; + ALuint BufferLength; + ALuint offset; + ALuint lfo_range; + ALfloat lfo_scale; + ALint lfo_disp; + + /* Gains for left and right sides */ + ALfloat Gain[2][MaxChannels]; + + /* effect parameters */ + ALint waveform; + ALint delay; + ALfloat depth; + ALfloat feedback; +} ALflangerState; + +static ALvoid ALflangerState_Destruct(ALflangerState *state) +{ + free(state->SampleBuffer[0]); + state->SampleBuffer[0] = NULL; + state->SampleBuffer[1] = NULL; +} + +static ALboolean ALflangerState_deviceUpdate(ALflangerState *state, ALCdevice *Device) +{ + ALuint maxlen; + ALuint it; + + maxlen = fastf2u(AL_FLANGER_MAX_DELAY * 3.0f * Device->Frequency) + 1; + maxlen = NextPowerOf2(maxlen); + + if(maxlen != state->BufferLength) + { + void *temp; + + temp = realloc(state->SampleBuffer[0], maxlen * sizeof(ALfloat) * 2); + if(!temp) return AL_FALSE; + state->SampleBuffer[0] = temp; + state->SampleBuffer[1] = state->SampleBuffer[0] + maxlen; + + state->BufferLength = maxlen; + } + + for(it = 0;it < state->BufferLength;it++) + { + state->SampleBuffer[0][it] = 0.0f; + state->SampleBuffer[1][it] = 0.0f; + } + + return AL_TRUE; +} + +static ALvoid ALflangerState_update(ALflangerState *state, ALCdevice *Device, const ALeffectslot *Slot) +{ + ALfloat frequency = (ALfloat)Device->Frequency; + ALfloat rate; + ALint phase; + + state->waveform = Slot->EffectProps.Flanger.Waveform; + state->depth = Slot->EffectProps.Flanger.Depth; + state->feedback = Slot->EffectProps.Flanger.Feedback; + state->delay = fastf2i(Slot->EffectProps.Flanger.Delay * frequency); + + /* Gains for left and right sides */ + ComputeAngleGains(Device, atan2f(-1.0f, 0.0f), 0.0f, Slot->Gain, state->Gain[0]); + ComputeAngleGains(Device, atan2f(+1.0f, 0.0f), 0.0f, Slot->Gain, state->Gain[1]); + + phase = Slot->EffectProps.Flanger.Phase; + rate = Slot->EffectProps.Flanger.Rate; + if(!(rate > 0.0f)) + { + state->lfo_scale = 0.0f; + state->lfo_range = 1; + state->lfo_disp = 0; + } + else + { + /* Calculate LFO coefficient */ + state->lfo_range = fastf2u(frequency/rate + 0.5f); + switch(state->waveform) + { + case AL_FLANGER_WAVEFORM_TRIANGLE: + state->lfo_scale = 4.0f / state->lfo_range; + break; + case AL_FLANGER_WAVEFORM_SINUSOID: + state->lfo_scale = F_2PI / state->lfo_range; + break; + } + + /* Calculate lfo phase displacement */ + state->lfo_disp = fastf2i(state->lfo_range * (phase/360.0f)); + } +} + +static inline void Triangle(ALint *delay_left, ALint *delay_right, ALuint offset, const ALflangerState *state) +{ + ALfloat lfo_value; + + lfo_value = 2.0f - fabsf(2.0f - state->lfo_scale*(offset%state->lfo_range)); + lfo_value *= state->depth * state->delay; + *delay_left = fastf2i(lfo_value) + state->delay; + + offset += state->lfo_disp; + lfo_value = 2.0f - fabsf(2.0f - state->lfo_scale*(offset%state->lfo_range)); + lfo_value *= state->depth * state->delay; + *delay_right = fastf2i(lfo_value) + state->delay; +} + +static inline void Sinusoid(ALint *delay_left, ALint *delay_right, ALuint offset, const ALflangerState *state) +{ + ALfloat lfo_value; + + lfo_value = 1.0f + sinf(state->lfo_scale*(offset%state->lfo_range)); + lfo_value *= state->depth * state->delay; + *delay_left = fastf2i(lfo_value) + state->delay; + + offset += state->lfo_disp; + lfo_value = 1.0f + sinf(state->lfo_scale*(offset%state->lfo_range)); + lfo_value *= state->depth * state->delay; + *delay_right = fastf2i(lfo_value) + state->delay; +} + +#define DECL_TEMPLATE(Func) \ +static void Process##Func(ALflangerState *state, const ALuint SamplesToDo, \ + const ALfloat *restrict SamplesIn, ALfloat (*restrict out)[2]) \ +{ \ + const ALuint bufmask = state->BufferLength-1; \ + ALfloat *restrict leftbuf = state->SampleBuffer[0]; \ + ALfloat *restrict rightbuf = state->SampleBuffer[1]; \ + ALuint offset = state->offset; \ + const ALfloat feedback = state->feedback; \ + ALuint it; \ + \ + for(it = 0;it < SamplesToDo;it++) \ + { \ + ALint delay_left, delay_right; \ + Func(&delay_left, &delay_right, offset, state); \ + \ + out[it][0] = leftbuf[(offset-delay_left)&bufmask]; \ + leftbuf[offset&bufmask] = (out[it][0]+SamplesIn[it]) * feedback; \ + \ + out[it][1] = rightbuf[(offset-delay_right)&bufmask]; \ + rightbuf[offset&bufmask] = (out[it][1]+SamplesIn[it]) * feedback; \ + \ + offset++; \ + } \ + state->offset = offset; \ +} + +DECL_TEMPLATE(Triangle) +DECL_TEMPLATE(Sinusoid) + +#undef DECL_TEMPLATE + +static ALvoid ALflangerState_process(ALflangerState *state, ALuint SamplesToDo, const ALfloat *restrict SamplesIn, ALfloat (*restrict SamplesOut)[BUFFERSIZE]) +{ + ALuint it, kt; + ALuint base; + + for(base = 0;base < SamplesToDo;) + { + ALfloat temps[64][2]; + ALuint td = minu(SamplesToDo-base, 64); + + if(state->waveform == AL_FLANGER_WAVEFORM_TRIANGLE) + ProcessTriangle(state, td, SamplesIn+base, temps); + else if(state->waveform == AL_FLANGER_WAVEFORM_SINUSOID) + ProcessSinusoid(state, td, SamplesIn+base, temps); + + for(kt = 0;kt < MaxChannels;kt++) + { + ALfloat gain = state->Gain[0][kt]; + if(gain > GAIN_SILENCE_THRESHOLD) + { + for(it = 0;it < td;it++) + SamplesOut[kt][it+base] += temps[it][0] * gain; + } + + gain = state->Gain[1][kt]; + if(gain > GAIN_SILENCE_THRESHOLD) + { + for(it = 0;it < td;it++) + SamplesOut[kt][it+base] += temps[it][1] * gain; + } + } + + base += td; + } +} + +static void ALflangerState_Delete(ALflangerState *state) +{ + free(state); +} + +DEFINE_ALEFFECTSTATE_VTABLE(ALflangerState); + + +typedef struct ALflangerStateFactory { + DERIVE_FROM_TYPE(ALeffectStateFactory); +} ALflangerStateFactory; + +ALeffectState *ALflangerStateFactory_create(ALflangerStateFactory *UNUSED(factory)) +{ + ALflangerState *state; + + state = malloc(sizeof(*state)); + if(!state) return NULL; + SET_VTABLE2(ALflangerState, ALeffectState, state); + + state->BufferLength = 0; + state->SampleBuffer[0] = NULL; + state->SampleBuffer[1] = NULL; + state->offset = 0; + state->lfo_range = 1; + + return STATIC_CAST(ALeffectState, state); +} + +DEFINE_ALEFFECTSTATEFACTORY_VTABLE(ALflangerStateFactory); + +ALeffectStateFactory *ALflangerStateFactory_getFactory(void) +{ + static ALflangerStateFactory FlangerFactory = { { GET_VTABLE2(ALflangerStateFactory, ALeffectStateFactory) } }; + + return STATIC_CAST(ALeffectStateFactory, &FlangerFactory); +} + + +void ALflanger_setParami(ALeffect *effect, ALCcontext *context, ALenum param, ALint val) +{ + ALeffectProps *props = &effect->Props; + switch(param) + { + case AL_FLANGER_WAVEFORM: + if(!(val >= AL_FLANGER_MIN_WAVEFORM && val <= AL_FLANGER_MAX_WAVEFORM)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Flanger.Waveform = val; + break; + + case AL_FLANGER_PHASE: + if(!(val >= AL_FLANGER_MIN_PHASE && val <= AL_FLANGER_MAX_PHASE)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Flanger.Phase = val; + break; + + default: + SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); + } +} +void ALflanger_setParamiv(ALeffect *effect, ALCcontext *context, ALenum param, const ALint *vals) +{ + ALflanger_setParami(effect, context, param, vals[0]); +} +void ALflanger_setParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat val) +{ + ALeffectProps *props = &effect->Props; + switch(param) + { + case AL_FLANGER_RATE: + if(!(val >= AL_FLANGER_MIN_RATE && val <= AL_FLANGER_MAX_RATE)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Flanger.Rate = val; + break; + + case AL_FLANGER_DEPTH: + if(!(val >= AL_FLANGER_MIN_DEPTH && val <= AL_FLANGER_MAX_DEPTH)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Flanger.Depth = val; + break; + + case AL_FLANGER_FEEDBACK: + if(!(val >= AL_FLANGER_MIN_FEEDBACK && val <= AL_FLANGER_MAX_FEEDBACK)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Flanger.Feedback = val; + break; + + case AL_FLANGER_DELAY: + if(!(val >= AL_FLANGER_MIN_DELAY && val <= AL_FLANGER_MAX_DELAY)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Flanger.Delay = val; + break; + + default: + SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); + } +} +void ALflanger_setParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals) +{ + ALflanger_setParamf(effect, context, param, vals[0]); +} + +void ALflanger_getParami(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *val) +{ + const ALeffectProps *props = &effect->Props; + switch(param) + { + case AL_FLANGER_WAVEFORM: + *val = props->Flanger.Waveform; + break; + + case AL_FLANGER_PHASE: + *val = props->Flanger.Phase; + break; + + default: + SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); + } +} +void ALflanger_getParamiv(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *vals) +{ + ALflanger_getParami(effect, context, param, vals); +} +void ALflanger_getParamf(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *val) +{ + const ALeffectProps *props = &effect->Props; + switch(param) + { + case AL_FLANGER_RATE: + *val = props->Flanger.Rate; + break; + + case AL_FLANGER_DEPTH: + *val = props->Flanger.Depth; + break; + + case AL_FLANGER_FEEDBACK: + *val = props->Flanger.Feedback; + break; + + case AL_FLANGER_DELAY: + *val = props->Flanger.Delay; + break; + + default: + SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); + } +} +void ALflanger_getParamfv(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals) +{ + ALflanger_getParamf(effect, context, param, vals); +} + +DEFINE_ALEFFECT_VTABLE(ALflanger); |