Alc/effects/flanger.c

   1 /**
   2  * OpenAL cross platform audio library
   3  * Copyright (C) 2013 by Mike Gorchak
   4  * This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU Library General Public
   6  *  License as published by the Free Software Foundation; either
   7  *  version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *  Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  *  License along with this library; if not, write to the
  16  *  Free Software Foundation, Inc.,
  17  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  * Or go to http://www.gnu.org/copyleft/lgpl.html
  19  */
  20
  21 #include "config.h"
  22
  23 #include <math.h>
  24 #include <stdlib.h>
  25
  26 #include "alMain.h"
  27 #include "alFilter.h"
  28 #include "alAuxEffectSlot.h"
  29 #include "alError.h"
  30 #include "alu.h"
  31
  32
  33 enum FlangerWaveForm {
  34     FWF_Triangle = AL_FLANGER_WAVEFORM_TRIANGLE,
  35     FWF_Sinusoid = AL_FLANGER_WAVEFORM_SINUSOID
  36 };
  37
  38 typedef struct ALflangerState {
  39     DERIVE_FROM_TYPE(ALeffectState);
  40
  41     ALfloat *SampleBuffer[2];
  42     ALuint BufferLength;
  43     ALuint offset;
  44     ALuint lfo_range;
  45     ALfloat lfo_scale;
  46     ALint lfo_disp;
  47
  48     /* Gains for left and right sides */
  49     ALfloat Gain[2][MAX_OUTPUT_CHANNELS];
  50
  51     /* effect parameters */
  52     enum FlangerWaveForm waveform;
  53     ALint delay;
  54     ALfloat depth;
  55     ALfloat feedback;
  56 } ALflangerState;
  57
  58 static ALvoid ALflangerState_Destruct(ALflangerState *state)
  59 {
  60     free(state->SampleBuffer[0]);
  61     state->SampleBuffer[0] = NULL;
  62     state->SampleBuffer[1] = NULL;
  63 }
  64
  65 static ALboolean ALflangerState_deviceUpdate(ALflangerState *state, ALCdevice *Device)
  66 {
  67     ALuint maxlen;
  68     ALuint it;
  69
  70     maxlen = fastf2u(AL_FLANGER_MAX_DELAY * 3.0f * Device->Frequency) + 1;
  71     maxlen = NextPowerOf2(maxlen);
  72
  73     if(maxlen != state->BufferLength)
  74     {
  75         void *temp;
  76
  77         temp = realloc(state->SampleBuffer[0], maxlen * sizeof(ALfloat) * 2);
  78         if(!temp) return AL_FALSE;
  79         state->SampleBuffer[0] = temp;
  80         state->SampleBuffer[1] = state->SampleBuffer[0] + maxlen;
  81
  82         state->BufferLength = maxlen;
  83     }
  84
  85     for(it = 0;it < state->BufferLength;it++)
  86     {
  87         state->SampleBuffer[0][it] = 0.0f;
  88         state->SampleBuffer[1][it] = 0.0f;
  89     }
  90
  91     return AL_TRUE;
  92 }
  93
  94 static ALvoid ALflangerState_update(ALflangerState *state, ALCdevice *Device, const ALeffectslot *Slot)
  95 {
  96     static const ALfloat left_dir[3] = { -1.0f, 0.0f, 0.0f };
  97     static const ALfloat right_dir[3] = { 1.0f, 0.0f, 0.0f };
  98     ALfloat frequency = (ALfloat)Device->Frequency;
  99     ALfloat rate;
 100     ALint phase;
 101
 102     switch(Slot->EffectProps.Flanger.Waveform)
 103     {
 104         case AL_FLANGER_WAVEFORM_TRIANGLE:
 105             state->waveform = FWF_Triangle;
 106             break;
 107         case AL_FLANGER_WAVEFORM_SINUSOID:
 108             state->waveform = FWF_Sinusoid;
 109             break;
 110     }
 111     state->depth = Slot->EffectProps.Flanger.Depth;
 112     state->feedback = Slot->EffectProps.Flanger.Feedback;
 113     state->delay = fastf2i(Slot->EffectProps.Flanger.Delay * frequency);
 114
 115     /* Gains for left and right sides */
 116     ComputeDirectionalGains(Device, left_dir, Slot->Gain, state->Gain[0]);
 117     ComputeDirectionalGains(Device, right_dir, Slot->Gain, state->Gain[1]);
 118
 119     phase = Slot->EffectProps.Flanger.Phase;
 120     rate = Slot->EffectProps.Flanger.Rate;
 121     if(!(rate > 0.0f))
 122     {
 123         state->lfo_scale = 0.0f;
 124         state->lfo_range = 1;
 125         state->lfo_disp = 0;
 126     }
 127     else
 128     {
 129         /* Calculate LFO coefficient */
 130         state->lfo_range = fastf2u(frequency/rate + 0.5f);
 131         switch(state->waveform)
 132         {
 133             case FWF_Triangle:
 134                 state->lfo_scale = 4.0f / state->lfo_range;
 135                 break;
 136             case FWF_Sinusoid:
 137                 state->lfo_scale = F_2PI / state->lfo_range;
 138                 break;
 139         }
 140
 141         /* Calculate lfo phase displacement */
 142         state->lfo_disp = fastf2i(state->lfo_range * (phase/360.0f));
 143     }
 144 }
 145
 146 static inline void Triangle(ALint *delay_left, ALint *delay_right, ALuint offset, const ALflangerState *state)
 147 {
 148     ALfloat lfo_value;
 149
 150     lfo_value = 2.0f - fabsf(2.0f - state->lfo_scale*(offset%state->lfo_range));
 151     lfo_value *= state->depth * state->delay;
 152     *delay_left = fastf2i(lfo_value) + state->delay;
 153
 154     offset += state->lfo_disp;
 155     lfo_value = 2.0f - fabsf(2.0f - state->lfo_scale*(offset%state->lfo_range));
 156     lfo_value *= state->depth * state->delay;
 157     *delay_right = fastf2i(lfo_value) + state->delay;
 158 }
 159
 160 static inline void Sinusoid(ALint *delay_left, ALint *delay_right, ALuint offset, const ALflangerState *state)
 161 {
 162     ALfloat lfo_value;
 163
 164     lfo_value = 1.0f + sinf(state->lfo_scale*(offset%state->lfo_range));
 165     lfo_value *= state->depth * state->delay;
 166     *delay_left = fastf2i(lfo_value) + state->delay;
 167
 168     offset += state->lfo_disp;
 169     lfo_value = 1.0f + sinf(state->lfo_scale*(offset%state->lfo_range));
 170     lfo_value *= state->depth * state->delay;
 171     *delay_right = fastf2i(lfo_value) + state->delay;
 172 }
 173
 174 #define DECL_TEMPLATE(Func)                                                   \
 175 static void Process##Func(ALflangerState *state, const ALuint SamplesToDo,    \
 176   const ALfloat *restrict SamplesIn, ALfloat (*restrict out)[2])              \
 177 {                                                                             \
 178     const ALuint bufmask = state->BufferLength-1;                             \
 179     ALfloat *restrict leftbuf = state->SampleBuffer[0];                       \
 180     ALfloat *restrict rightbuf = state->SampleBuffer[1];                      \
 181     ALuint offset = state->offset;                                            \
 182     const ALfloat feedback = state->feedback;                                 \
 183     ALuint it;                                                                \
 184                                                                               \
 185     for(it = 0;it < SamplesToDo;it++)                                         \
 186     {                                                                         \
 187         ALint delay_left, delay_right;                                        \
 188         Func(&delay_left, &delay_right, offset, state);                       \
 189                                                                               \
 190         out[it][0] = leftbuf[(offset-delay_left)&bufmask];                    \
 191         leftbuf[offset&bufmask] = (out[it][0]+SamplesIn[it]) * feedback;      \
 192                                                                               \
 193         out[it][1] = rightbuf[(offset-delay_right)&bufmask];                  \
 194         rightbuf[offset&bufmask] = (out[it][1]+SamplesIn[it]) * feedback;     \
 195                                                                               \
 196         offset++;                                                             \
 197     }                                                                         \
 198     state->offset = offset;                                                   \
 199 }
 200
 201 DECL_TEMPLATE(Triangle)
 202 DECL_TEMPLATE(Sinusoid)
 203
 204 #undef DECL_TEMPLATE
 205
 206 static ALvoid ALflangerState_process(ALflangerState *state, ALuint SamplesToDo, const ALfloat *restrict SamplesIn, ALfloat (*restrict SamplesOut)[BUFFERSIZE], ALuint NumChannels)
 207 {
 208     ALuint it, kt;
 209     ALuint base;
 210
 211     for(base = 0;base < SamplesToDo;)
 212     {
 213         ALfloat temps[64][2];
 214         ALuint td = minu(SamplesToDo-base, 64);
 215
 216         switch(state->waveform)
 217         {
 218             case FWF_Triangle:
 219                 ProcessTriangle(state, td, SamplesIn+base, temps);
 220                 break;
 221             case FWF_Sinusoid:
 222                 ProcessSinusoid(state, td, SamplesIn+base, temps);
 223                 break;
 224         }
 225
 226         for(kt = 0;kt < NumChannels;kt++)
 227         {
 228             ALfloat gain = state->Gain[0][kt];
 229             if(fabsf(gain) > GAIN_SILENCE_THRESHOLD)
 230             {
 231                 for(it = 0;it < td;it++)
 232                     SamplesOut[kt][it+base] += temps[it][0] * gain;
 233             }
 234
 235             gain = state->Gain[1][kt];
 236             if(fabsf(gain) > GAIN_SILENCE_THRESHOLD)
 237             {
 238                 for(it = 0;it < td;it++)
 239                     SamplesOut[kt][it+base] += temps[it][1] * gain;
 240             }
 241         }
 242
 243         base += td;
 244     }
 245 }
 246
 247 DECLARE_DEFAULT_ALLOCATORS(ALflangerState)
 248
 249 DEFINE_ALEFFECTSTATE_VTABLE(ALflangerState);
 250
 251
 252 typedef struct ALflangerStateFactory {
 253     DERIVE_FROM_TYPE(ALeffectStateFactory);
 254 } ALflangerStateFactory;
 255
 256 ALeffectState *ALflangerStateFactory_create(ALflangerStateFactory *UNUSED(factory))
 257 {
 258     ALflangerState *state;
 259
 260     state = ALflangerState_New(sizeof(*state));
 261     if(!state) return NULL;
 262     SET_VTABLE2(ALflangerState, ALeffectState, state);
 263
 264     state->BufferLength = 0;
 265     state->SampleBuffer[0] = NULL;
 266     state->SampleBuffer[1] = NULL;
 267     state->offset = 0;
 268     state->lfo_range = 1;
 269     state->waveform = FWF_Triangle;
 270
 271     return STATIC_CAST(ALeffectState, state);
 272 }
 273
 274 DEFINE_ALEFFECTSTATEFACTORY_VTABLE(ALflangerStateFactory);
 275
 276 ALeffectStateFactory *ALflangerStateFactory_getFactory(void)
 277 {
 278     static ALflangerStateFactory FlangerFactory = { { GET_VTABLE2(ALflangerStateFactory, ALeffectStateFactory) } };
 279
 280     return STATIC_CAST(ALeffectStateFactory, &FlangerFactory);
 281 }
 282
 283
 284 void ALflanger_setParami(ALeffect *effect, ALCcontext *context, ALenum param, ALint val)
 285 {
 286     ALeffectProps *props = &effect->Props;
 287     switch(param)
 288     {
 289         case AL_FLANGER_WAVEFORM:
 290             if(!(val >= AL_FLANGER_MIN_WAVEFORM && val <= AL_FLANGER_MAX_WAVEFORM))
 291                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 292             props->Flanger.Waveform = val;
 293             break;
 294
 295         case AL_FLANGER_PHASE:
 296             if(!(val >= AL_FLANGER_MIN_PHASE && val <= AL_FLANGER_MAX_PHASE))
 297                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 298             props->Flanger.Phase = val;
 299             break;
 300
 301         default:
 302             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 303     }
 304 }
 305 void ALflanger_setParamiv(ALeffect *effect, ALCcontext *context, ALenum param, const ALint *vals)
 306 {
 307     ALflanger_setParami(effect, context, param, vals[0]);
 308 }
 309 void ALflanger_setParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat val)
 310 {
 311     ALeffectProps *props = &effect->Props;
 312     switch(param)
 313     {
 314         case AL_FLANGER_RATE:
 315             if(!(val >= AL_FLANGER_MIN_RATE && val <= AL_FLANGER_MAX_RATE))
 316                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 317             props->Flanger.Rate = val;
 318             break;
 319
 320         case AL_FLANGER_DEPTH:
 321             if(!(val >= AL_FLANGER_MIN_DEPTH && val <= AL_FLANGER_MAX_DEPTH))
 322                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 323             props->Flanger.Depth = val;
 324             break;
 325
 326         case AL_FLANGER_FEEDBACK:
 327             if(!(val >= AL_FLANGER_MIN_FEEDBACK && val <= AL_FLANGER_MAX_FEEDBACK))
 328                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 329             props->Flanger.Feedback = val;
 330             break;
 331
 332         case AL_FLANGER_DELAY:
 333             if(!(val >= AL_FLANGER_MIN_DELAY && val <= AL_FLANGER_MAX_DELAY))
 334                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 335             props->Flanger.Delay = val;
 336             break;
 337
 338         default:
 339             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 340     }
 341 }
 342 void ALflanger_setParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals)
 343 {
 344     ALflanger_setParamf(effect, context, param, vals[0]);
 345 }
 346
 347 void ALflanger_getParami(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *val)
 348 {
 349     const ALeffectProps *props = &effect->Props;
 350     switch(param)
 351     {
 352         case AL_FLANGER_WAVEFORM:
 353             *val = props->Flanger.Waveform;
 354             break;
 355
 356         case AL_FLANGER_PHASE:
 357             *val = props->Flanger.Phase;
 358             break;
 359
 360         default:
 361             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 362     }
 363 }
 364 void ALflanger_getParamiv(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *vals)
 365 {
 366     ALflanger_getParami(effect, context, param, vals);
 367 }
 368 void ALflanger_getParamf(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *val)
 369 {
 370     const ALeffectProps *props = &effect->Props;
 371     switch(param)
 372     {
 373         case AL_FLANGER_RATE:
 374             *val = props->Flanger.Rate;
 375             break;
 376
 377         case AL_FLANGER_DEPTH:
 378             *val = props->Flanger.Depth;
 379             break;
 380
 381         case AL_FLANGER_FEEDBACK:
 382             *val = props->Flanger.Feedback;
 383             break;
 384
 385         case AL_FLANGER_DELAY:
 386             *val = props->Flanger.Delay;
 387             break;
 388
 389         default:
 390             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 391     }
 392 }
 393 void ALflanger_getParamfv(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals)
 394 {
 395     ALflanger_getParamf(effect, context, param, vals);
 396 }
 397
 398 DEFINE_ALEFFECT_VTABLE(ALflanger);