Alc/effects/modulator.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
  32
  33 typedef struct ALmodulatorState {
  34     DERIVE_FROM_TYPE(ALeffectState);
  35
  36     void (*Process)(ALfloat*, const ALfloat*, ALuint, const ALuint, ALuint);
  37
  38     ALuint index;
  39     ALuint step;
  40
  41     ALfloat Gain[MAX_OUTPUT_CHANNELS];
  42
  43     ALfilterState Filter;
  44 } ALmodulatorState;
  45
  46 #define WAVEFORM_FRACBITS  24
  47 #define WAVEFORM_FRACONE   (1<<WAVEFORM_FRACBITS)
  48 #define WAVEFORM_FRACMASK  (WAVEFORM_FRACONE-1)
  49
  50 static inline ALfloat Sin(ALuint index)
  51 {
  52     return sinf(index*(F_TAU/WAVEFORM_FRACONE) - F_PI)*0.5f + 0.5f;
  53 }
  54
  55 static inline ALfloat Saw(ALuint index)
  56 {
  57     return (ALfloat)index / WAVEFORM_FRACONE;
  58 }
  59
  60 static inline ALfloat Square(ALuint index)
  61 {
  62     return (ALfloat)((index >> (WAVEFORM_FRACBITS - 1)) & 1);
  63 }
  64
  65 #define DECL_TEMPLATE(func)                                                   \
  66 static void Modulate##func(ALfloat *restrict dst, const ALfloat *restrict src,\
  67                            ALuint index, const ALuint step, ALuint todo)      \
  68 {                                                                             \
  69     ALuint i;                                                                 \
  70     for(i = 0;i < todo;i++)                                                   \
  71     {                                                                         \
  72         index += step;                                                        \
  73         index &= WAVEFORM_FRACMASK;                                           \
  74         dst[i] = src[i] * func(index);                                        \
  75     }                                                                         \
  76 }
  77
  78 DECL_TEMPLATE(Sin)
  79 DECL_TEMPLATE(Saw)
  80 DECL_TEMPLATE(Square)
  81
  82 #undef DECL_TEMPLATE
  83
  84
  85 static ALvoid ALmodulatorState_Destruct(ALmodulatorState *UNUSED(state))
  86 {
  87 }
  88
  89 static ALboolean ALmodulatorState_deviceUpdate(ALmodulatorState *UNUSED(state), ALCdevice *UNUSED(device))
  90 {
  91     return AL_TRUE;
  92 }
  93
  94 static ALvoid ALmodulatorState_update(ALmodulatorState *state, const ALCdevice *Device, const ALeffectslot *Slot)
  95 {
  96     ALfloat cw, a;
  97
  98     if(Slot->EffectProps.Modulator.Waveform == AL_RING_MODULATOR_SINUSOID)
  99         state->Process = ModulateSin;
 100     else if(Slot->EffectProps.Modulator.Waveform == AL_RING_MODULATOR_SAWTOOTH)
 101         state->Process = ModulateSaw;
 102     else /*if(Slot->EffectProps.Modulator.Waveform == AL_RING_MODULATOR_SQUARE)*/
 103         state->Process = ModulateSquare;
 104
 105     state->step = fastf2u(Slot->EffectProps.Modulator.Frequency*WAVEFORM_FRACONE /
 106                           Device->Frequency);
 107     if(state->step == 0) state->step = 1;
 108
 109     /* Custom filter coeffs, which match the old version instead of a low-shelf. */
 110     cw = cosf(F_TAU * Slot->EffectProps.Modulator.HighPassCutoff / Device->Frequency);
 111     a = (2.0f-cw) - sqrtf(powf(2.0f-cw, 2.0f) - 1.0f);
 112
 113     state->Filter.a1 = -a;
 114     state->Filter.a2 = 0.0f;
 115     state->Filter.b1 = -a;
 116     state->Filter.b2 = 0.0f;
 117     state->Filter.input_gain = a;
 118     state->Filter.process = ALfilterState_processC;
 119
 120     ComputeAmbientGains(Device->AmbiCoeffs, Device->NumChannels, Slot->Gain, state->Gain);
 121 }
 122
 123 static ALvoid ALmodulatorState_process(ALmodulatorState *state, ALuint SamplesToDo, const ALfloat (*restrict SamplesIn)[BUFFERSIZE], ALfloat (*restrict SamplesOut)[BUFFERSIZE], ALuint NumChannels)
 124 {
 125     const ALuint step = state->step;
 126     ALuint index = state->index;
 127     ALuint base;
 128
 129     for(base = 0;base < SamplesToDo;)
 130     {
 131         ALfloat temps[2][128];
 132         ALuint td = minu(128, SamplesToDo-base);
 133         ALuint i, k;
 134
 135         ALfilterState_process(&state->Filter, temps[0], &SamplesIn[0][base], td);
 136         state->Process(temps[1], temps[0], index, step, td);
 137
 138         for(k = 0;k < NumChannels;k++)
 139         {
 140             ALfloat gain = state->Gain[k];
 141             if(!(fabsf(gain) > GAIN_SILENCE_THRESHOLD))
 142                 continue;
 143
 144             for(i = 0;i < td;i++)
 145                 SamplesOut[k][base+i] += gain * temps[1][i];
 146         }
 147
 148         for(i = 0;i < td;i++)
 149         {
 150             index += step;
 151             index &= WAVEFORM_FRACMASK;
 152         }
 153         base += td;
 154     }
 155     state->index = index;
 156 }
 157
 158 DECLARE_DEFAULT_ALLOCATORS(ALmodulatorState)
 159
 160 DEFINE_ALEFFECTSTATE_VTABLE(ALmodulatorState);
 161
 162
 163 typedef struct ALmodulatorStateFactory {
 164     DERIVE_FROM_TYPE(ALeffectStateFactory);
 165 } ALmodulatorStateFactory;
 166
 167 static ALeffectState *ALmodulatorStateFactory_create(ALmodulatorStateFactory *UNUSED(factory))
 168 {
 169     ALmodulatorState *state;
 170
 171     state = ALmodulatorState_New(sizeof(*state));
 172     if(!state) return NULL;
 173     SET_VTABLE2(ALmodulatorState, ALeffectState, state);
 174
 175     state->index = 0;
 176     state->step = 1;
 177
 178     ALfilterState_clear(&state->Filter);
 179
 180     return STATIC_CAST(ALeffectState, state);
 181 }
 182
 183 DEFINE_ALEFFECTSTATEFACTORY_VTABLE(ALmodulatorStateFactory);
 184
 185 ALeffectStateFactory *ALmodulatorStateFactory_getFactory(void)
 186 {
 187     static ALmodulatorStateFactory ModulatorFactory = { { GET_VTABLE2(ALmodulatorStateFactory, ALeffectStateFactory) } };
 188
 189     return STATIC_CAST(ALeffectStateFactory, &ModulatorFactory);
 190 }
 191
 192
 193 void ALmodulator_setParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat val)
 194 {
 195     ALeffectProps *props = &effect->Props;
 196     switch(param)
 197     {
 198         case AL_RING_MODULATOR_FREQUENCY:
 199             if(!(val >= AL_RING_MODULATOR_MIN_FREQUENCY && val <= AL_RING_MODULATOR_MAX_FREQUENCY))
 200                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 201             props->Modulator.Frequency = val;
 202             break;
 203
 204         case AL_RING_MODULATOR_HIGHPASS_CUTOFF:
 205             if(!(val >= AL_RING_MODULATOR_MIN_HIGHPASS_CUTOFF && val <= AL_RING_MODULATOR_MAX_HIGHPASS_CUTOFF))
 206                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 207             props->Modulator.HighPassCutoff = val;
 208             break;
 209
 210         default:
 211             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 212     }
 213 }
 214 void ALmodulator_setParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals)
 215 {
 216     ALmodulator_setParamf(effect, context, param, vals[0]);
 217 }
 218 void ALmodulator_setParami(ALeffect *effect, ALCcontext *context, ALenum param, ALint val)
 219 {
 220     ALeffectProps *props = &effect->Props;
 221     switch(param)
 222     {
 223         case AL_RING_MODULATOR_FREQUENCY:
 224         case AL_RING_MODULATOR_HIGHPASS_CUTOFF:
 225             ALmodulator_setParamf(effect, context, param, (ALfloat)val);
 226             break;
 227
 228         case AL_RING_MODULATOR_WAVEFORM:
 229             if(!(val >= AL_RING_MODULATOR_MIN_WAVEFORM && val <= AL_RING_MODULATOR_MAX_WAVEFORM))
 230                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 231             props->Modulator.Waveform = val;
 232             break;
 233
 234         default:
 235             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 236     }
 237 }
 238 void ALmodulator_setParamiv(ALeffect *effect, ALCcontext *context, ALenum param, const ALint *vals)
 239 {
 240     ALmodulator_setParami(effect, context, param, vals[0]);
 241 }
 242
 243 void ALmodulator_getParami(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *val)
 244 {
 245     const ALeffectProps *props = &effect->Props;
 246     switch(param)
 247     {
 248         case AL_RING_MODULATOR_FREQUENCY:
 249             *val = (ALint)props->Modulator.Frequency;
 250             break;
 251         case AL_RING_MODULATOR_HIGHPASS_CUTOFF:
 252             *val = (ALint)props->Modulator.HighPassCutoff;
 253             break;
 254         case AL_RING_MODULATOR_WAVEFORM:
 255             *val = props->Modulator.Waveform;
 256             break;
 257
 258         default:
 259             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 260     }
 261 }
 262 void ALmodulator_getParamiv(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *vals)
 263 {
 264     ALmodulator_getParami(effect, context, param, vals);
 265 }
 266 void ALmodulator_getParamf(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *val)
 267 {
 268     const ALeffectProps *props = &effect->Props;
 269     switch(param)
 270     {
 271         case AL_RING_MODULATOR_FREQUENCY:
 272             *val = props->Modulator.Frequency;
 273             break;
 274         case AL_RING_MODULATOR_HIGHPASS_CUTOFF:
 275             *val = props->Modulator.HighPassCutoff;
 276             break;
 277
 278         default:
 279             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 280     }
 281 }
 282 void ALmodulator_getParamfv(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals)
 283 {
 284     ALmodulator_getParamf(effect, context, param, vals);
 285 }
 286
 287 DEFINE_ALEFFECT_VTABLE(ALmodulator);