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     enum {
  37         SINUSOID,
  38         SAWTOOTH,
  39         SQUARE
  40     } Waveform;
  41
  42     ALuint index;
  43     ALuint step;
  44
  45     ALfloat Gain[MAX_OUTPUT_CHANNELS];
  46
  47     ALfilterState Filter;
  48 } ALmodulatorState;
  49
  50 #define WAVEFORM_FRACBITS  24
  51 #define WAVEFORM_FRACONE   (1<<WAVEFORM_FRACBITS)
  52 #define WAVEFORM_FRACMASK  (WAVEFORM_FRACONE-1)
  53
  54 static inline ALfloat Sin(ALuint index)
  55 {
  56     return sinf(index*(F_TAU/WAVEFORM_FRACONE) - F_PI)*0.5f + 0.5f;
  57 }
  58
  59 static inline ALfloat Saw(ALuint index)
  60 {
  61     return (ALfloat)index / WAVEFORM_FRACONE;
  62 }
  63
  64 static inline ALfloat Square(ALuint index)
  65 {
  66     return (ALfloat)((index >> (WAVEFORM_FRACBITS - 1)) & 1);
  67 }
  68
  69 #define DECL_TEMPLATE(func)                                                   \
  70 static void Process##func(ALmodulatorState *state, ALuint SamplesToDo,        \
  71   const ALfloat *restrict SamplesIn,                                          \
  72   ALfloat (*restrict SamplesOut)[BUFFERSIZE], ALuint NumChannels)             \
  73 {                                                                             \
  74     const ALuint step = state->step;                                          \
  75     ALuint index = state->index;                                              \
  76     ALuint base;                                                              \
  77                                                                               \
  78     for(base = 0;base < SamplesToDo;)                                         \
  79     {                                                                         \
  80         ALfloat temps[256];                                                   \
  81         ALuint td = minu(256, SamplesToDo-base);                              \
  82         ALuint i, k;                                                          \
  83                                                                               \
  84         for(i = 0;i < td;i++)                                                 \
  85         {                                                                     \
  86             ALfloat samp;                                                     \
  87             samp = SamplesIn[base+i];                                         \
  88             samp = ALfilterState_processSingle(&state->Filter, samp);         \
  89                                                                               \
  90             index += step;                                                    \
  91             index &= WAVEFORM_FRACMASK;                                       \
  92             temps[i] = samp * func(index);                                    \
  93         }                                                                     \
  94                                                                               \
  95         for(k = 0;k < NumChannels;k++)                                        \
  96         {                                                                     \
  97             ALfloat gain = state->Gain[k];                                    \
  98             if(!(fabsf(gain) > GAIN_SILENCE_THRESHOLD))                       \
  99                 continue;                                                     \
 100                                                                               \
 101             for(i = 0;i < td;i++)                                             \
 102                 SamplesOut[k][base+i] += gain * temps[i];                     \
 103         }                                                                     \
 104                                                                               \
 105         base += td;                                                           \
 106     }                                                                         \
 107     state->index = index;                                                     \
 108 }
 109
 110 DECL_TEMPLATE(Sin)
 111 DECL_TEMPLATE(Saw)
 112 DECL_TEMPLATE(Square)
 113
 114 #undef DECL_TEMPLATE
 115
 116
 117 static ALvoid ALmodulatorState_Destruct(ALmodulatorState *UNUSED(state))
 118 {
 119 }
 120
 121 static ALboolean ALmodulatorState_deviceUpdate(ALmodulatorState *UNUSED(state), ALCdevice *UNUSED(device))
 122 {
 123     return AL_TRUE;
 124 }
 125
 126 static ALvoid ALmodulatorState_update(ALmodulatorState *state, ALCdevice *Device, const ALeffectslot *Slot)
 127 {
 128     ALfloat cw, a;
 129
 130     if(Slot->EffectProps.Modulator.Waveform == AL_RING_MODULATOR_SINUSOID)
 131         state->Waveform = SINUSOID;
 132     else if(Slot->EffectProps.Modulator.Waveform == AL_RING_MODULATOR_SAWTOOTH)
 133         state->Waveform = SAWTOOTH;
 134     else if(Slot->EffectProps.Modulator.Waveform == AL_RING_MODULATOR_SQUARE)
 135         state->Waveform = SQUARE;
 136
 137     state->step = fastf2u(Slot->EffectProps.Modulator.Frequency*WAVEFORM_FRACONE /
 138                           Device->Frequency);
 139     if(state->step == 0) state->step = 1;
 140
 141     /* Custom filter coeffs, which match the old version instead of a low-shelf. */
 142     cw = cosf(F_TAU * Slot->EffectProps.Modulator.HighPassCutoff / Device->Frequency);
 143     a = (2.0f-cw) - sqrtf(powf(2.0f-cw, 2.0f) - 1.0f);
 144
 145     state->Filter.a1 = -a;
 146     state->Filter.a2 = 0.0f;
 147     state->Filter.b1 = -a;
 148     state->Filter.b2 = 0.0f;
 149     state->Filter.input_gain = a;
 150
 151     ComputeAmbientGains(Device, Slot->Gain, state->Gain);
 152 }
 153
 154 static ALvoid ALmodulatorState_process(ALmodulatorState *state, ALuint SamplesToDo, const ALfloat *restrict SamplesIn, ALfloat (*restrict SamplesOut)[BUFFERSIZE], ALuint NumChannels)
 155 {
 156     switch(state->Waveform)
 157     {
 158         case SINUSOID:
 159             ProcessSin(state, SamplesToDo, SamplesIn, SamplesOut, NumChannels);
 160             break;
 161
 162         case SAWTOOTH:
 163             ProcessSaw(state, SamplesToDo, SamplesIn, SamplesOut, NumChannels);
 164             break;
 165
 166         case SQUARE:
 167             ProcessSquare(state, SamplesToDo, SamplesIn, SamplesOut, NumChannels);
 168             break;
 169     }
 170 }
 171
 172 DECLARE_DEFAULT_ALLOCATORS(ALmodulatorState)
 173
 174 DEFINE_ALEFFECTSTATE_VTABLE(ALmodulatorState);
 175
 176
 177 typedef struct ALmodulatorStateFactory {
 178     DERIVE_FROM_TYPE(ALeffectStateFactory);
 179 } ALmodulatorStateFactory;
 180
 181 static ALeffectState *ALmodulatorStateFactory_create(ALmodulatorStateFactory *UNUSED(factory))
 182 {
 183     ALmodulatorState *state;
 184
 185     state = ALmodulatorState_New(sizeof(*state));
 186     if(!state) return NULL;
 187     SET_VTABLE2(ALmodulatorState, ALeffectState, state);
 188
 189     state->index = 0;
 190     state->step = 1;
 191
 192     ALfilterState_clear(&state->Filter);
 193
 194     return STATIC_CAST(ALeffectState, state);
 195 }
 196
 197 DEFINE_ALEFFECTSTATEFACTORY_VTABLE(ALmodulatorStateFactory);
 198
 199 ALeffectStateFactory *ALmodulatorStateFactory_getFactory(void)
 200 {
 201     static ALmodulatorStateFactory ModulatorFactory = { { GET_VTABLE2(ALmodulatorStateFactory, ALeffectStateFactory) } };
 202
 203     return STATIC_CAST(ALeffectStateFactory, &ModulatorFactory);
 204 }
 205
 206
 207 void ALmodulator_setParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat val)
 208 {
 209     ALeffectProps *props = &effect->Props;
 210     switch(param)
 211     {
 212         case AL_RING_MODULATOR_FREQUENCY:
 213             if(!(val >= AL_RING_MODULATOR_MIN_FREQUENCY && val <= AL_RING_MODULATOR_MAX_FREQUENCY))
 214                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 215             props->Modulator.Frequency = val;
 216             break;
 217
 218         case AL_RING_MODULATOR_HIGHPASS_CUTOFF:
 219             if(!(val >= AL_RING_MODULATOR_MIN_HIGHPASS_CUTOFF && val <= AL_RING_MODULATOR_MAX_HIGHPASS_CUTOFF))
 220                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 221             props->Modulator.HighPassCutoff = val;
 222             break;
 223
 224         default:
 225             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 226     }
 227 }
 228 void ALmodulator_setParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals)
 229 {
 230     ALmodulator_setParamf(effect, context, param, vals[0]);
 231 }
 232 void ALmodulator_setParami(ALeffect *effect, ALCcontext *context, ALenum param, ALint val)
 233 {
 234     ALeffectProps *props = &effect->Props;
 235     switch(param)
 236     {
 237         case AL_RING_MODULATOR_FREQUENCY:
 238         case AL_RING_MODULATOR_HIGHPASS_CUTOFF:
 239             ALmodulator_setParamf(effect, context, param, (ALfloat)val);
 240             break;
 241
 242         case AL_RING_MODULATOR_WAVEFORM:
 243             if(!(val >= AL_RING_MODULATOR_MIN_WAVEFORM && val <= AL_RING_MODULATOR_MAX_WAVEFORM))
 244                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 245             props->Modulator.Waveform = val;
 246             break;
 247
 248         default:
 249             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 250     }
 251 }
 252 void ALmodulator_setParamiv(ALeffect *effect, ALCcontext *context, ALenum param, const ALint *vals)
 253 {
 254     ALmodulator_setParami(effect, context, param, vals[0]);
 255 }
 256
 257 void ALmodulator_getParami(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *val)
 258 {
 259     const ALeffectProps *props = &effect->Props;
 260     switch(param)
 261     {
 262         case AL_RING_MODULATOR_FREQUENCY:
 263             *val = (ALint)props->Modulator.Frequency;
 264             break;
 265         case AL_RING_MODULATOR_HIGHPASS_CUTOFF:
 266             *val = (ALint)props->Modulator.HighPassCutoff;
 267             break;
 268         case AL_RING_MODULATOR_WAVEFORM:
 269             *val = props->Modulator.Waveform;
 270             break;
 271
 272         default:
 273             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 274     }
 275 }
 276 void ALmodulator_getParamiv(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *vals)
 277 {
 278     ALmodulator_getParami(effect, context, param, vals);
 279 }
 280 void ALmodulator_getParamf(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *val)
 281 {
 282     const ALeffectProps *props = &effect->Props;
 283     switch(param)
 284     {
 285         case AL_RING_MODULATOR_FREQUENCY:
 286             *val = props->Modulator.Frequency;
 287             break;
 288         case AL_RING_MODULATOR_HIGHPASS_CUTOFF:
 289             *val = props->Modulator.HighPassCutoff;
 290             break;
 291
 292         default:
 293             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 294     }
 295 }
 296 void ALmodulator_getParamfv(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals)
 297 {
 298     ALmodulator_getParamf(effect, context, param, vals);
 299 }
 300
 301 DEFINE_ALEFFECT_VTABLE(ALmodulator);