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, const ALCdevice *Device, const ALeffectslot *Slot)
  95 {
  96     ALfloat frequency = (ALfloat)Device->Frequency;
  97     ALfloat coeffs[MAX_AMBI_COEFFS];
  98     ALfloat rate;
  99     ALint phase;
 100
 101     switch(Slot->EffectProps.Flanger.Waveform)
 102     {
 103         case AL_FLANGER_WAVEFORM_TRIANGLE:
 104             state->waveform = FWF_Triangle;
 105             break;
 106         case AL_FLANGER_WAVEFORM_SINUSOID:
 107             state->waveform = FWF_Sinusoid;
 108             break;
 109     }
 110     state->depth = Slot->EffectProps.Flanger.Depth;
 111     state->feedback = Slot->EffectProps.Flanger.Feedback;
 112     state->delay = fastf2i(Slot->EffectProps.Flanger.Delay * frequency);
 113
 114     /* Gains for left and right sides */
 115     CalcXYZCoeffs(-1.0f, 0.0f, 0.0f, 0.0f, coeffs);
 116     ComputePanningGains(Device->Dry, coeffs, Slot->Gain, state->Gain[0]);
 117     CalcXYZCoeffs( 1.0f, 0.0f, 0.0f, 0.0f, coeffs);
 118     ComputePanningGains(Device->Dry, coeffs, Slot->Gain, state->Gain[1]);
 119
 120     phase = Slot->EffectProps.Flanger.Phase;
 121     rate = Slot->EffectProps.Flanger.Rate;
 122     if(!(rate > 0.0f))
 123     {
 124         state->lfo_scale = 0.0f;
 125         state->lfo_range = 1;
 126         state->lfo_disp = 0;
 127     }
 128     else
 129     {
 130         /* Calculate LFO coefficient */
 131         state->lfo_range = fastf2u(frequency/rate + 0.5f);
 132         switch(state->waveform)
 133         {
 134             case FWF_Triangle:
 135                 state->lfo_scale = 4.0f / state->lfo_range;
 136                 break;
 137             case FWF_Sinusoid:
 138                 state->lfo_scale = F_TAU / state->lfo_range;
 139                 break;
 140         }
 141
 142         /* Calculate lfo phase displacement */
 143         state->lfo_disp = fastf2i(state->lfo_range * (phase/360.0f));
 144     }
 145 }
 146
 147 static inline void Triangle(ALint *delay_left, ALint *delay_right, ALuint offset, const ALflangerState *state)
 148 {
 149     ALfloat lfo_value;
 150
 151     lfo_value = 2.0f - fabsf(2.0f - state->lfo_scale*(offset%state->lfo_range));
 152     lfo_value *= state->depth * state->delay;
 153     *delay_left = fastf2i(lfo_value) + state->delay;
 154
 155     offset += state->lfo_disp;
 156     lfo_value = 2.0f - fabsf(2.0f - state->lfo_scale*(offset%state->lfo_range));
 157     lfo_value *= state->depth * state->delay;
 158     *delay_right = fastf2i(lfo_value) + state->delay;
 159 }
 160
 161 static inline void Sinusoid(ALint *delay_left, ALint *delay_right, ALuint offset, const ALflangerState *state)
 162 {
 163     ALfloat lfo_value;
 164
 165     lfo_value = 1.0f + sinf(state->lfo_scale*(offset%state->lfo_range));
 166     lfo_value *= state->depth * state->delay;
 167     *delay_left = fastf2i(lfo_value) + state->delay;
 168
 169     offset += state->lfo_disp;
 170     lfo_value = 1.0f + sinf(state->lfo_scale*(offset%state->lfo_range));
 171     lfo_value *= state->depth * state->delay;
 172     *delay_right = fastf2i(lfo_value) + state->delay;
 173 }
 174
 175 #define DECL_TEMPLATE(Func)                                                   \
 176 static void Process##Func(ALflangerState *state, const ALuint SamplesToDo,    \
 177   const ALfloat *restrict SamplesIn, ALfloat (*restrict out)[2])              \
 178 {                                                                             \
 179     const ALuint bufmask = state->BufferLength-1;                             \
 180     ALfloat *restrict leftbuf = state->SampleBuffer[0];                       \
 181     ALfloat *restrict rightbuf = state->SampleBuffer[1];                      \
 182     ALuint offset = state->offset;                                            \
 183     const ALfloat feedback = state->feedback;                                 \
 184     ALuint it;                                                                \
 185                                                                               \
 186     for(it = 0;it < SamplesToDo;it++)                                         \
 187     {                                                                         \
 188         ALint delay_left, delay_right;                                        \
 189         Func(&delay_left, &delay_right, offset, state);                       \
 190                                                                               \
 191         out[it][0] = leftbuf[(offset-delay_left)&bufmask];                    \
 192         leftbuf[offset&bufmask] = (out[it][0]+SamplesIn[it]) * feedback;      \
 193                                                                               \
 194         out[it][1] = rightbuf[(offset-delay_right)&bufmask];                  \
 195         rightbuf[offset&bufmask] = (out[it][1]+SamplesIn[it]) * feedback;     \
 196                                                                               \
 197         offset++;                                                             \
 198     }                                                                         \
 199     state->offset = offset;                                                   \
 200 }
 201
 202 DECL_TEMPLATE(Triangle)
 203 DECL_TEMPLATE(Sinusoid)
 204
 205 #undef DECL_TEMPLATE
 206
 207 static ALvoid ALflangerState_process(ALflangerState *state, ALuint SamplesToDo, const ALfloat (*restrict SamplesIn)[BUFFERSIZE], ALfloat (*restrict SamplesOut)[BUFFERSIZE], ALuint NumChannels)
 208 {
 209     ALuint it, kt;
 210     ALuint base;
 211
 212     for(base = 0;base < SamplesToDo;)
 213     {
 214         ALfloat temps[128][2];
 215         ALuint td = minu(128, SamplesToDo-base);
 216
 217         switch(state->waveform)
 218         {
 219             case FWF_Triangle:
 220                 ProcessTriangle(state, td, SamplesIn[0]+base, temps);
 221                 break;
 222             case FWF_Sinusoid:
 223                 ProcessSinusoid(state, td, SamplesIn[0]+base, temps);
 224                 break;
 225         }
 226
 227         for(kt = 0;kt < NumChannels;kt++)
 228         {
 229             ALfloat gain = state->Gain[0][kt];
 230             if(fabsf(gain) > GAIN_SILENCE_THRESHOLD)
 231             {
 232                 for(it = 0;it < td;it++)
 233                     SamplesOut[kt][it+base] += temps[it][0] * gain;
 234             }
 235
 236             gain = state->Gain[1][kt];
 237             if(fabsf(gain) > GAIN_SILENCE_THRESHOLD)
 238             {
 239                 for(it = 0;it < td;it++)
 240                     SamplesOut[kt][it+base] += temps[it][1] * gain;
 241             }
 242         }
 243
 244         base += td;
 245     }
 246 }
 247
 248 DECLARE_DEFAULT_ALLOCATORS(ALflangerState)
 249
 250 DEFINE_ALEFFECTSTATE_VTABLE(ALflangerState);
 251
 252
 253 typedef struct ALflangerStateFactory {
 254     DERIVE_FROM_TYPE(ALeffectStateFactory);
 255 } ALflangerStateFactory;
 256
 257 ALeffectState *ALflangerStateFactory_create(ALflangerStateFactory *UNUSED(factory))
 258 {
 259     ALflangerState *state;
 260
 261     state = ALflangerState_New(sizeof(*state));
 262     if(!state) return NULL;
 263     SET_VTABLE2(ALflangerState, ALeffectState, state);
 264
 265     state->BufferLength = 0;
 266     state->SampleBuffer[0] = NULL;
 267     state->SampleBuffer[1] = NULL;
 268     state->offset = 0;
 269     state->lfo_range = 1;
 270     state->waveform = FWF_Triangle;
 271
 272     return STATIC_CAST(ALeffectState, state);
 273 }
 274
 275 DEFINE_ALEFFECTSTATEFACTORY_VTABLE(ALflangerStateFactory);
 276
 277 ALeffectStateFactory *ALflangerStateFactory_getFactory(void)
 278 {
 279     static ALflangerStateFactory FlangerFactory = { { GET_VTABLE2(ALflangerStateFactory, ALeffectStateFactory) } };
 280
 281     return STATIC_CAST(ALeffectStateFactory, &FlangerFactory);
 282 }
 283
 284
 285 void ALflanger_setParami(ALeffect *effect, ALCcontext *context, ALenum param, ALint val)
 286 {
 287     ALeffectProps *props = &effect->Props;
 288     switch(param)
 289     {
 290         case AL_FLANGER_WAVEFORM:
 291             if(!(val >= AL_FLANGER_MIN_WAVEFORM && val <= AL_FLANGER_MAX_WAVEFORM))
 292                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 293             props->Flanger.Waveform = val;
 294             break;
 295
 296         case AL_FLANGER_PHASE:
 297             if(!(val >= AL_FLANGER_MIN_PHASE && val <= AL_FLANGER_MAX_PHASE))
 298                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 299             props->Flanger.Phase = val;
 300             break;
 301
 302         default:
 303             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 304     }
 305 }
 306 void ALflanger_setParamiv(ALeffect *effect, ALCcontext *context, ALenum param, const ALint *vals)
 307 {
 308     ALflanger_setParami(effect, context, param, vals[0]);
 309 }
 310 void ALflanger_setParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat val)
 311 {
 312     ALeffectProps *props = &effect->Props;
 313     switch(param)
 314     {
 315         case AL_FLANGER_RATE:
 316             if(!(val >= AL_FLANGER_MIN_RATE && val <= AL_FLANGER_MAX_RATE))
 317                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 318             props->Flanger.Rate = val;
 319             break;
 320
 321         case AL_FLANGER_DEPTH:
 322             if(!(val >= AL_FLANGER_MIN_DEPTH && val <= AL_FLANGER_MAX_DEPTH))
 323                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 324             props->Flanger.Depth = val;
 325             break;
 326
 327         case AL_FLANGER_FEEDBACK:
 328             if(!(val >= AL_FLANGER_MIN_FEEDBACK && val <= AL_FLANGER_MAX_FEEDBACK))
 329                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 330             props->Flanger.Feedback = val;
 331             break;
 332
 333         case AL_FLANGER_DELAY:
 334             if(!(val >= AL_FLANGER_MIN_DELAY && val <= AL_FLANGER_MAX_DELAY))
 335                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 336             props->Flanger.Delay = val;
 337             break;
 338
 339         default:
 340             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 341     }
 342 }
 343 void ALflanger_setParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals)
 344 {
 345     ALflanger_setParamf(effect, context, param, vals[0]);
 346 }
 347
 348 void ALflanger_getParami(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *val)
 349 {
 350     const ALeffectProps *props = &effect->Props;
 351     switch(param)
 352     {
 353         case AL_FLANGER_WAVEFORM:
 354             *val = props->Flanger.Waveform;
 355             break;
 356
 357         case AL_FLANGER_PHASE:
 358             *val = props->Flanger.Phase;
 359             break;
 360
 361         default:
 362             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 363     }
 364 }
 365 void ALflanger_getParamiv(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *vals)
 366 {
 367     ALflanger_getParami(effect, context, param, vals);
 368 }
 369 void ALflanger_getParamf(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *val)
 370 {
 371     const ALeffectProps *props = &effect->Props;
 372     switch(param)
 373     {
 374         case AL_FLANGER_RATE:
 375             *val = props->Flanger.Rate;
 376             break;
 377
 378         case AL_FLANGER_DEPTH:
 379             *val = props->Flanger.Depth;
 380             break;
 381
 382         case AL_FLANGER_FEEDBACK:
 383             *val = props->Flanger.Feedback;
 384             break;
 385
 386         case AL_FLANGER_DELAY:
 387             *val = props->Flanger.Delay;
 388             break;
 389
 390         default:
 391             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 392     }
 393 }
 394 void ALflanger_getParamfv(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals)
 395 {
 396     ALflanger_getParamf(effect, context, param, vals);
 397 }
 398
 399 DEFINE_ALEFFECT_VTABLE(ALflanger);