Alc/effects/echo.c

   1 /**
   2  * OpenAL cross platform audio library
   3  * Copyright (C) 2009 by Chris Robinson.
   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 #include "filters/defs.h"
  32
  33
  34 typedef struct ALechoState {
  35     DERIVE_FROM_TYPE(ALeffectState);
  36
  37     ALfloat *SampleBuffer;
  38     ALsizei BufferLength;
  39
  40     // The echo is two tap. The delay is the number of samples from before the
  41     // current offset
  42     struct {
  43         ALsizei delay;
  44     } Tap[2];
  45     ALsizei Offset;
  46
  47     /* The panning gains for the two taps */
  48     struct {
  49         ALfloat Current[MAX_OUTPUT_CHANNELS];
  50         ALfloat Target[MAX_OUTPUT_CHANNELS];
  51     } Gains[2];
  52
  53     ALfloat FeedGain;
  54
  55     BiquadState Filter;
  56 } ALechoState;
  57
  58 static ALvoid ALechoState_Destruct(ALechoState *state);
  59 static ALboolean ALechoState_deviceUpdate(ALechoState *state, ALCdevice *Device);
  60 static ALvoid ALechoState_update(ALechoState *state, const ALCcontext *context, const ALeffectslot *slot, const ALeffectProps *props);
  61 static ALvoid ALechoState_process(ALechoState *state, ALsizei SamplesToDo, const ALfloat (*restrict SamplesIn)[BUFFERSIZE], ALfloat (*restrict SamplesOut)[BUFFERSIZE], ALsizei NumChannels);
  62 DECLARE_DEFAULT_ALLOCATORS(ALechoState)
  63
  64 DEFINE_ALEFFECTSTATE_VTABLE(ALechoState);
  65
  66
  67 static void ALechoState_Construct(ALechoState *state)
  68 {
  69     ALeffectState_Construct(STATIC_CAST(ALeffectState, state));
  70     SET_VTABLE2(ALechoState, ALeffectState, state);
  71
  72     state->BufferLength = 0;
  73     state->SampleBuffer = NULL;
  74
  75     state->Tap[0].delay = 0;
  76     state->Tap[1].delay = 0;
  77     state->Offset = 0;
  78
  79     BiquadState_clear(&state->Filter);
  80 }
  81
  82 static ALvoid ALechoState_Destruct(ALechoState *state)
  83 {
  84     al_free(state->SampleBuffer);
  85     state->SampleBuffer = NULL;
  86     ALeffectState_Destruct(STATIC_CAST(ALeffectState,state));
  87 }
  88
  89 static ALboolean ALechoState_deviceUpdate(ALechoState *state, ALCdevice *Device)
  90 {
  91     ALsizei maxlen;
  92
  93     // Use the next power of 2 for the buffer length, so the tap offsets can be
  94     // wrapped using a mask instead of a modulo
  95     maxlen = fastf2i(AL_ECHO_MAX_DELAY*Device->Frequency + 0.5f) +
  96              fastf2i(AL_ECHO_MAX_LRDELAY*Device->Frequency + 0.5f);
  97     maxlen = NextPowerOf2(maxlen);
  98     if(maxlen <= 0) return AL_FALSE;
  99
 100     if(maxlen != state->BufferLength)
 101     {
 102         void *temp = al_calloc(16, maxlen * sizeof(ALfloat));
 103         if(!temp) return AL_FALSE;
 104
 105         al_free(state->SampleBuffer);
 106         state->SampleBuffer = temp;
 107         state->BufferLength = maxlen;
 108     }
 109
 110     memset(state->SampleBuffer, 0, state->BufferLength*sizeof(ALfloat));
 111     memset(state->Gains, 0, sizeof(state->Gains));
 112
 113     return AL_TRUE;
 114 }
 115
 116 static ALvoid ALechoState_update(ALechoState *state, const ALCcontext *context, const ALeffectslot *slot, const ALeffectProps *props)
 117 {
 118     const ALCdevice *device = context->Device;
 119     ALuint frequency = device->Frequency;
 120     ALfloat coeffs[MAX_AMBI_COEFFS];
 121     ALfloat gainhf, lrpan, spread;
 122
 123     state->Tap[0].delay = maxi(fastf2i(props->Echo.Delay*frequency + 0.5f), 1);
 124     state->Tap[1].delay = fastf2i(props->Echo.LRDelay*frequency + 0.5f);
 125     state->Tap[1].delay += state->Tap[0].delay;
 126
 127     spread = props->Echo.Spread;
 128     if(spread < 0.0f) lrpan = -1.0f;
 129     else lrpan = 1.0f;
 130     /* Convert echo spread (where 0 = omni, +/-1 = directional) to coverage
 131      * spread (where 0 = point, tau = omni).
 132      */
 133     spread = asinf(1.0f - fabsf(spread))*4.0f;
 134
 135     state->FeedGain = props->Echo.Feedback;
 136
 137     gainhf = maxf(1.0f - props->Echo.Damping, 0.0625f); /* Limit -24dB */
 138     BiquadState_setParams(&state->Filter, BiquadType_HighShelf,
 139                           gainhf, LOWPASSFREQREF/frequency,
 140                           calc_rcpQ_from_slope(gainhf, 1.0f));
 141
 142     /* First tap panning */
 143     CalcAngleCoeffs(-F_PI_2*lrpan, 0.0f, spread, coeffs);
 144     ComputeDryPanGains(&device->Dry, coeffs, slot->Params.Gain, state->Gains[0].Target);
 145
 146     /* Second tap panning */
 147     CalcAngleCoeffs( F_PI_2*lrpan, 0.0f, spread, coeffs);
 148     ComputeDryPanGains(&device->Dry, coeffs, slot->Params.Gain, state->Gains[1].Target);
 149 }
 150
 151 static ALvoid ALechoState_process(ALechoState *state, ALsizei SamplesToDo, const ALfloat (*restrict SamplesIn)[BUFFERSIZE], ALfloat (*restrict SamplesOut)[BUFFERSIZE], ALsizei NumChannels)
 152 {
 153     const ALsizei mask = state->BufferLength-1;
 154     const ALsizei tap1 = state->Tap[0].delay;
 155     const ALsizei tap2 = state->Tap[1].delay;
 156     ALfloat *restrict delaybuf = state->SampleBuffer;
 157     ALsizei offset = state->Offset;
 158     ALfloat x[2], y[2], in, out;
 159     ALsizei base;
 160     ALsizei c, i;
 161
 162     x[0] = state->Filter.x[0];
 163     x[1] = state->Filter.x[1];
 164     y[0] = state->Filter.y[0];
 165     y[1] = state->Filter.y[1];
 166     for(base = 0;base < SamplesToDo;)
 167     {
 168         alignas(16) ALfloat temps[2][128];
 169         ALsizei td = mini(128, SamplesToDo-base);
 170
 171         for(i = 0;i < td;i++)
 172         {
 173             /* Feed the delay buffer's input first. */
 174             delaybuf[offset&mask] = SamplesIn[0][i+base];
 175
 176             /* First tap */
 177             temps[0][i] = delaybuf[(offset-tap1) & mask];
 178             /* Second tap */
 179             temps[1][i] = delaybuf[(offset-tap2) & mask];
 180
 181             /* Apply damping to the second tap, then add it to the buffer with
 182              * feedback attenuation.
 183              */
 184             in = temps[1][i];
 185             out = in*state->Filter.b0 +
 186                   x[0]*state->Filter.b1 + x[1]*state->Filter.b2 -
 187                   y[0]*state->Filter.a1 - y[1]*state->Filter.a2;
 188             x[1] = x[0]; x[0] = in;
 189             y[1] = y[0]; y[0] = out;
 190
 191             delaybuf[offset&mask] += out * state->FeedGain;
 192             offset++;
 193         }
 194
 195         for(c = 0;c < 2;c++)
 196             MixSamples(temps[c], NumChannels, SamplesOut, state->Gains[c].Current,
 197                        state->Gains[c].Target, SamplesToDo-base, base, td);
 198
 199         base += td;
 200     }
 201     state->Filter.x[0] = x[0];
 202     state->Filter.x[1] = x[1];
 203     state->Filter.y[0] = y[0];
 204     state->Filter.y[1] = y[1];
 205
 206     state->Offset = offset;
 207 }
 208
 209
 210 typedef struct EchoStateFactory {
 211     DERIVE_FROM_TYPE(EffectStateFactory);
 212 } EchoStateFactory;
 213
 214 ALeffectState *EchoStateFactory_create(EchoStateFactory *UNUSED(factory))
 215 {
 216     ALechoState *state;
 217
 218     NEW_OBJ0(state, ALechoState)();
 219     if(!state) return NULL;
 220
 221     return STATIC_CAST(ALeffectState, state);
 222 }
 223
 224 DEFINE_EFFECTSTATEFACTORY_VTABLE(EchoStateFactory);
 225
 226 EffectStateFactory *EchoStateFactory_getFactory(void)
 227 {
 228     static EchoStateFactory EchoFactory = { { GET_VTABLE2(EchoStateFactory, EffectStateFactory) } };
 229
 230     return STATIC_CAST(EffectStateFactory, &EchoFactory);
 231 }
 232
 233
 234 void ALecho_setParami(ALeffect *UNUSED(effect), ALCcontext *context, ALenum param, ALint UNUSED(val))
 235 { alSetError(context, AL_INVALID_ENUM, "Invalid echo integer property 0x%04x", param); }
 236 void ALecho_setParamiv(ALeffect *UNUSED(effect), ALCcontext *context, ALenum param, const ALint *UNUSED(vals))
 237 { alSetError(context, AL_INVALID_ENUM, "Invalid echo integer-vector property 0x%04x", param); }
 238 void ALecho_setParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat val)
 239 {
 240     ALeffectProps *props = &effect->Props;
 241     switch(param)
 242     {
 243         case AL_ECHO_DELAY:
 244             if(!(val >= AL_ECHO_MIN_DELAY && val <= AL_ECHO_MAX_DELAY))
 245                 SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo delay out of range");
 246             props->Echo.Delay = val;
 247             break;
 248
 249         case AL_ECHO_LRDELAY:
 250             if(!(val >= AL_ECHO_MIN_LRDELAY && val <= AL_ECHO_MAX_LRDELAY))
 251                 SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo LR delay out of range");
 252             props->Echo.LRDelay = val;
 253             break;
 254
 255         case AL_ECHO_DAMPING:
 256             if(!(val >= AL_ECHO_MIN_DAMPING && val <= AL_ECHO_MAX_DAMPING))
 257                 SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo damping out of range");
 258             props->Echo.Damping = val;
 259             break;
 260
 261         case AL_ECHO_FEEDBACK:
 262             if(!(val >= AL_ECHO_MIN_FEEDBACK && val <= AL_ECHO_MAX_FEEDBACK))
 263                 SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo feedback out of range");
 264             props->Echo.Feedback = val;
 265             break;
 266
 267         case AL_ECHO_SPREAD:
 268             if(!(val >= AL_ECHO_MIN_SPREAD && val <= AL_ECHO_MAX_SPREAD))
 269                 SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo spread out of range");
 270             props->Echo.Spread = val;
 271             break;
 272
 273         default:
 274             alSetError(context, AL_INVALID_ENUM, "Invalid echo float property 0x%04x", param);
 275     }
 276 }
 277 void ALecho_setParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals)
 278 { ALecho_setParamf(effect, context, param, vals[0]); }
 279
 280 void ALecho_getParami(const ALeffect *UNUSED(effect), ALCcontext *context, ALenum param, ALint *UNUSED(val))
 281 { alSetError(context, AL_INVALID_ENUM, "Invalid echo integer property 0x%04x", param); }
 282 void ALecho_getParamiv(const ALeffect *UNUSED(effect), ALCcontext *context, ALenum param, ALint *UNUSED(vals))
 283 { alSetError(context, AL_INVALID_ENUM, "Invalid echo integer-vector property 0x%04x", param); }
 284 void ALecho_getParamf(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *val)
 285 {
 286     const ALeffectProps *props = &effect->Props;
 287     switch(param)
 288     {
 289         case AL_ECHO_DELAY:
 290             *val = props->Echo.Delay;
 291             break;
 292
 293         case AL_ECHO_LRDELAY:
 294             *val = props->Echo.LRDelay;
 295             break;
 296
 297         case AL_ECHO_DAMPING:
 298             *val = props->Echo.Damping;
 299             break;
 300
 301         case AL_ECHO_FEEDBACK:
 302             *val = props->Echo.Feedback;
 303             break;
 304
 305         case AL_ECHO_SPREAD:
 306             *val = props->Echo.Spread;
 307             break;
 308
 309         default:
 310             alSetError(context, AL_INVALID_ENUM, "Invalid echo float property 0x%04x", param);
 311     }
 312 }
 313 void ALecho_getParamfv(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals)
 314 { ALecho_getParamf(effect, context, param, vals); }
 315
 316 DEFINE_ALEFFECT_VTABLE(ALecho);