Alc/effects/echo.cpp

   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 "alcontext.h"
  28 #include "alFilter.h"
  29 #include "alAuxEffectSlot.h"
  30 #include "alError.h"
  31 #include "alu.h"
  32 #include "filters/defs.h"
  33
  34
  35 struct ALechoState final : public ALeffectState {
  36     ALfloat *SampleBuffer;
  37     ALsizei BufferLength;
  38
  39     // The echo is two tap. The delay is the number of samples from before the
  40     // current offset
  41     struct {
  42         ALsizei delay;
  43     } Tap[2];
  44     ALsizei Offset;
  45
  46     /* The panning gains for the two taps */
  47     struct {
  48         ALfloat Current[MAX_OUTPUT_CHANNELS];
  49         ALfloat Target[MAX_OUTPUT_CHANNELS];
  50     } Gains[2];
  51
  52     ALfloat FeedGain;
  53
  54     BiquadFilter Filter;
  55 };
  56
  57 static ALvoid ALechoState_Destruct(ALechoState *state);
  58 static ALboolean ALechoState_deviceUpdate(ALechoState *state, ALCdevice *Device);
  59 static ALvoid ALechoState_update(ALechoState *state, const ALCcontext *context, const ALeffectslot *slot, const ALeffectProps *props);
  60 static ALvoid ALechoState_process(ALechoState *state, ALsizei SamplesToDo, const ALfloat (*RESTRICT SamplesIn)[BUFFERSIZE], ALfloat (*RESTRICT SamplesOut)[BUFFERSIZE], ALsizei NumChannels);
  61 DECLARE_DEFAULT_ALLOCATORS(ALechoState)
  62
  63 DEFINE_ALEFFECTSTATE_VTABLE(ALechoState);
  64
  65
  66 static void ALechoState_Construct(ALechoState *state)
  67 {
  68     new (state) ALechoState{};
  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     BiquadFilter_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     state->~ALechoState();
  88 }
  89
  90 static ALboolean ALechoState_deviceUpdate(ALechoState *state, ALCdevice *Device)
  91 {
  92     ALsizei maxlen;
  93
  94     // Use the next power of 2 for the buffer length, so the tap offsets can be
  95     // wrapped using a mask instead of a modulo
  96     maxlen = float2int(AL_ECHO_MAX_DELAY*Device->Frequency + 0.5f) +
  97              float2int(AL_ECHO_MAX_LRDELAY*Device->Frequency + 0.5f);
  98     maxlen = NextPowerOf2(maxlen);
  99     if(maxlen <= 0) return AL_FALSE;
 100
 101     if(maxlen != state->BufferLength)
 102     {
 103         void *temp = al_calloc(16, maxlen * sizeof(ALfloat));
 104         if(!temp) return AL_FALSE;
 105
 106         al_free(state->SampleBuffer);
 107         state->SampleBuffer = static_cast<float*>(temp);
 108         state->BufferLength = maxlen;
 109     }
 110
 111     memset(state->SampleBuffer, 0, state->BufferLength*sizeof(ALfloat));
 112     memset(state->Gains, 0, sizeof(state->Gains));
 113
 114     return AL_TRUE;
 115 }
 116
 117 static ALvoid ALechoState_update(ALechoState *state, const ALCcontext *context, const ALeffectslot *slot, const ALeffectProps *props)
 118 {
 119     const ALCdevice *device = context->Device;
 120     ALuint frequency = device->Frequency;
 121     ALfloat coeffs[MAX_AMBI_COEFFS];
 122     ALfloat gainhf, lrpan, spread;
 123
 124     state->Tap[0].delay = maxi(float2int(props->Echo.Delay*frequency + 0.5f), 1);
 125     state->Tap[1].delay = float2int(props->Echo.LRDelay*frequency + 0.5f);
 126     state->Tap[1].delay += state->Tap[0].delay;
 127
 128     spread = props->Echo.Spread;
 129     if(spread < 0.0f) lrpan = -1.0f;
 130     else lrpan = 1.0f;
 131     /* Convert echo spread (where 0 = omni, +/-1 = directional) to coverage
 132      * spread (where 0 = point, tau = omni).
 133      */
 134     spread = asinf(1.0f - fabsf(spread))*4.0f;
 135
 136     state->FeedGain = props->Echo.Feedback;
 137
 138     gainhf = maxf(1.0f - props->Echo.Damping, 0.0625f); /* Limit -24dB */
 139     BiquadFilter_setParams(&state->Filter, BiquadType_HighShelf,
 140         gainhf, LOWPASSFREQREF/frequency, calc_rcpQ_from_slope(gainhf, 1.0f)
 141     );
 142
 143     /* First tap panning */
 144     CalcAngleCoeffs(-F_PI_2*lrpan, 0.0f, spread, coeffs);
 145     ComputePanGains(&device->Dry, coeffs, slot->Params.Gain, state->Gains[0].Target);
 146
 147     /* Second tap panning */
 148     CalcAngleCoeffs( F_PI_2*lrpan, 0.0f, spread, coeffs);
 149     ComputePanGains(&device->Dry, coeffs, slot->Params.Gain, state->Gains[1].Target);
 150 }
 151
 152 static ALvoid ALechoState_process(ALechoState *state, ALsizei SamplesToDo, const ALfloat (*RESTRICT SamplesIn)[BUFFERSIZE], ALfloat (*RESTRICT SamplesOut)[BUFFERSIZE], ALsizei NumChannels)
 153 {
 154     const ALsizei mask = state->BufferLength-1;
 155     const ALsizei tap1 = state->Tap[0].delay;
 156     const ALsizei tap2 = state->Tap[1].delay;
 157     ALfloat *RESTRICT delaybuf = state->SampleBuffer;
 158     ALsizei offset = state->Offset;
 159     ALfloat z1, z2, in, out;
 160     ALsizei base;
 161     ALsizei c, i;
 162
 163     z1 = state->Filter.z1;
 164     z2 = state->Filter.z2;
 165     for(base = 0;base < SamplesToDo;)
 166     {
 167         alignas(16) ALfloat temps[2][128];
 168         ALsizei td = mini(128, SamplesToDo-base);
 169
 170         for(i = 0;i < td;i++)
 171         {
 172             /* Feed the delay buffer's input first. */
 173             delaybuf[offset&mask] = SamplesIn[0][i+base];
 174
 175             /* First tap */
 176             temps[0][i] = delaybuf[(offset-tap1) & mask];
 177             /* Second tap */
 178             temps[1][i] = delaybuf[(offset-tap2) & mask];
 179
 180             /* Apply damping to the second tap, then add it to the buffer with
 181              * feedback attenuation.
 182              */
 183             in = temps[1][i];
 184             out = in*state->Filter.b0 + z1;
 185             z1 = in*state->Filter.b1 - out*state->Filter.a1 + z2;
 186             z2 = in*state->Filter.b2 - out*state->Filter.a2;
 187
 188             delaybuf[offset&mask] += out * state->FeedGain;
 189             offset++;
 190         }
 191
 192         for(c = 0;c < 2;c++)
 193             MixSamples(temps[c], NumChannels, SamplesOut, state->Gains[c].Current,
 194                        state->Gains[c].Target, SamplesToDo-base, base, td);
 195
 196         base += td;
 197     }
 198     state->Filter.z1 = z1;
 199     state->Filter.z2 = z2;
 200
 201     state->Offset = offset;
 202 }
 203
 204
 205 struct EchoStateFactory final : public EffectStateFactory {
 206     ALeffectState *create() override;
 207 };
 208
 209 ALeffectState *EchoStateFactory::create()
 210 {
 211     ALechoState *state;
 212     NEW_OBJ0(state, ALechoState)();
 213     return state;
 214 }
 215
 216 EffectStateFactory *EchoStateFactory_getFactory(void)
 217 {
 218     static EchoStateFactory EchoFactory{};
 219     return &EchoFactory;
 220 }
 221
 222
 223 void ALecho_setParami(ALeffect *UNUSED(effect), ALCcontext *context, ALenum param, ALint UNUSED(val))
 224 { alSetError(context, AL_INVALID_ENUM, "Invalid echo integer property 0x%04x", param); }
 225 void ALecho_setParamiv(ALeffect *UNUSED(effect), ALCcontext *context, ALenum param, const ALint *UNUSED(vals))
 226 { alSetError(context, AL_INVALID_ENUM, "Invalid echo integer-vector property 0x%04x", param); }
 227 void ALecho_setParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat val)
 228 {
 229     ALeffectProps *props = &effect->Props;
 230     switch(param)
 231     {
 232         case AL_ECHO_DELAY:
 233             if(!(val >= AL_ECHO_MIN_DELAY && val <= AL_ECHO_MAX_DELAY))
 234                 SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo delay out of range");
 235             props->Echo.Delay = val;
 236             break;
 237
 238         case AL_ECHO_LRDELAY:
 239             if(!(val >= AL_ECHO_MIN_LRDELAY && val <= AL_ECHO_MAX_LRDELAY))
 240                 SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo LR delay out of range");
 241             props->Echo.LRDelay = val;
 242             break;
 243
 244         case AL_ECHO_DAMPING:
 245             if(!(val >= AL_ECHO_MIN_DAMPING && val <= AL_ECHO_MAX_DAMPING))
 246                 SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo damping out of range");
 247             props->Echo.Damping = val;
 248             break;
 249
 250         case AL_ECHO_FEEDBACK:
 251             if(!(val >= AL_ECHO_MIN_FEEDBACK && val <= AL_ECHO_MAX_FEEDBACK))
 252                 SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo feedback out of range");
 253             props->Echo.Feedback = val;
 254             break;
 255
 256         case AL_ECHO_SPREAD:
 257             if(!(val >= AL_ECHO_MIN_SPREAD && val <= AL_ECHO_MAX_SPREAD))
 258                 SETERR_RETURN(context, AL_INVALID_VALUE,, "Echo spread out of range");
 259             props->Echo.Spread = val;
 260             break;
 261
 262         default:
 263             alSetError(context, AL_INVALID_ENUM, "Invalid echo float property 0x%04x", param);
 264     }
 265 }
 266 void ALecho_setParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals)
 267 { ALecho_setParamf(effect, context, param, vals[0]); }
 268
 269 void ALecho_getParami(const ALeffect *UNUSED(effect), ALCcontext *context, ALenum param, ALint *UNUSED(val))
 270 { alSetError(context, AL_INVALID_ENUM, "Invalid echo integer property 0x%04x", param); }
 271 void ALecho_getParamiv(const ALeffect *UNUSED(effect), ALCcontext *context, ALenum param, ALint *UNUSED(vals))
 272 { alSetError(context, AL_INVALID_ENUM, "Invalid echo integer-vector property 0x%04x", param); }
 273 void ALecho_getParamf(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *val)
 274 {
 275     const ALeffectProps *props = &effect->Props;
 276     switch(param)
 277     {
 278         case AL_ECHO_DELAY:
 279             *val = props->Echo.Delay;
 280             break;
 281
 282         case AL_ECHO_LRDELAY:
 283             *val = props->Echo.LRDelay;
 284             break;
 285
 286         case AL_ECHO_DAMPING:
 287             *val = props->Echo.Damping;
 288             break;
 289
 290         case AL_ECHO_FEEDBACK:
 291             *val = props->Echo.Feedback;
 292             break;
 293
 294         case AL_ECHO_SPREAD:
 295             *val = props->Echo.Spread;
 296             break;
 297
 298         default:
 299             alSetError(context, AL_INVALID_ENUM, "Invalid echo float property 0x%04x", param);
 300     }
 301 }
 302 void ALecho_getParamfv(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals)
 303 { ALecho_getParamf(effect, context, param, vals); }
 304
 305 DEFINE_ALEFFECT_VTABLE(ALecho);