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-rw-r--r--Alc/effects/echo.c324
1 files changed, 324 insertions, 0 deletions
diff --git a/Alc/effects/echo.c b/Alc/effects/echo.c
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+++ b/Alc/effects/echo.c
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+/**
+ * OpenAL cross platform audio library
+ * Copyright (C) 2009 by Chris Robinson.
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ * Or go to http://www.gnu.org/copyleft/lgpl.html
+ */
+
+#include "config.h"
+
+#include <math.h>
+#include <stdlib.h>
+
+#include "alMain.h"
+#include "alFilter.h"
+#include "alAuxEffectSlot.h"
+#include "alError.h"
+#include "alu.h"
+
+
+typedef struct ALechoStateFactory {
+ DERIVE_FROM_TYPE(ALeffectStateFactory);
+} ALechoStateFactory;
+
+static ALechoStateFactory EchoFactory;
+
+
+typedef struct ALechoState {
+ DERIVE_FROM_TYPE(ALeffectState);
+
+ ALfloat *SampleBuffer;
+ ALuint BufferLength;
+
+ // The echo is two tap. The delay is the number of samples from before the
+ // current offset
+ struct {
+ ALuint delay;
+ } Tap[2];
+ ALuint Offset;
+ /* The panning gains for the two taps */
+ ALfloat Gain[2][MaxChannels];
+
+ ALfloat FeedGain;
+
+ FILTER iirFilter;
+} ALechoState;
+
+static ALvoid ALechoState_Destruct(ALechoState *state)
+{
+ free(state->SampleBuffer);
+ state->SampleBuffer = NULL;
+}
+
+static ALboolean ALechoState_DeviceUpdate(ALechoState *state, ALCdevice *Device)
+{
+ ALuint maxlen, i;
+
+ // Use the next power of 2 for the buffer length, so the tap offsets can be
+ // wrapped using a mask instead of a modulo
+ maxlen = fastf2u(AL_ECHO_MAX_DELAY * Device->Frequency) + 1;
+ maxlen += fastf2u(AL_ECHO_MAX_LRDELAY * Device->Frequency) + 1;
+ maxlen = NextPowerOf2(maxlen);
+
+ if(maxlen != state->BufferLength)
+ {
+ void *temp;
+
+ temp = realloc(state->SampleBuffer, maxlen * sizeof(ALfloat));
+ if(!temp)
+ return AL_FALSE;
+ state->SampleBuffer = temp;
+ state->BufferLength = maxlen;
+ }
+ for(i = 0;i < state->BufferLength;i++)
+ state->SampleBuffer[i] = 0.0f;
+
+ return AL_TRUE;
+}
+
+static ALvoid ALechoState_Update(ALechoState *state, ALCdevice *Device, const ALeffectslot *Slot)
+{
+ ALuint frequency = Device->Frequency;
+ ALfloat lrpan, cw, g, gain;
+ ALfloat dirGain;
+ ALuint i;
+
+ state->Tap[0].delay = fastf2u(Slot->effect.Echo.Delay * frequency) + 1;
+ state->Tap[1].delay = fastf2u(Slot->effect.Echo.LRDelay * frequency);
+ state->Tap[1].delay += state->Tap[0].delay;
+
+ lrpan = Slot->effect.Echo.Spread;
+
+ state->FeedGain = Slot->effect.Echo.Feedback;
+
+ cw = cosf(F_PI*2.0f * LOWPASSFREQREF / frequency);
+ g = 1.0f - Slot->effect.Echo.Damping;
+ state->iirFilter.coeff = lpCoeffCalc(g, cw);
+
+ gain = Slot->Gain;
+ for(i = 0;i < MaxChannels;i++)
+ {
+ state->Gain[0][i] = 0.0f;
+ state->Gain[1][i] = 0.0f;
+ }
+
+ dirGain = fabsf(lrpan);
+
+ /* First tap panning */
+ ComputeAngleGains(Device, atan2f(-lrpan, 0.0f), (1.0f-dirGain)*F_PI, gain, state->Gain[0]);
+
+ /* Second tap panning */
+ ComputeAngleGains(Device, atan2f(+lrpan, 0.0f), (1.0f-dirGain)*F_PI, gain, state->Gain[1]);
+}
+
+static ALvoid ALechoState_Process(ALechoState *state, ALuint SamplesToDo, const ALfloat *restrict SamplesIn, ALfloat (*restrict SamplesOut)[BUFFERSIZE])
+{
+ const ALuint mask = state->BufferLength-1;
+ const ALuint tap1 = state->Tap[0].delay;
+ const ALuint tap2 = state->Tap[1].delay;
+ ALuint offset = state->Offset;
+ ALfloat smp;
+ ALuint base;
+ ALuint i, k;
+
+ for(base = 0;base < SamplesToDo;)
+ {
+ ALfloat temps[64][2];
+ ALuint td = minu(SamplesToDo-base, 64);
+
+ for(i = 0;i < td;i++)
+ {
+ /* First tap */
+ temps[i][0] = state->SampleBuffer[(offset-tap1) & mask];
+ /* Second tap */
+ temps[i][1] = state->SampleBuffer[(offset-tap2) & mask];
+
+ // Apply damping and feedback gain to the second tap, and mix in the
+ // new sample
+ smp = lpFilter2P(&state->iirFilter, temps[i][1]+SamplesIn[i]);
+ state->SampleBuffer[offset&mask] = smp * state->FeedGain;
+ }
+
+ for(k = 0;k < MaxChannels;k++)
+ {
+ ALfloat gain = state->Gain[0][k];
+ if(gain > 0.00001f)
+ {
+ for(i = 0;i < td;i++)
+ SamplesOut[k][i+base] += temps[i][0] * gain;
+ }
+
+ gain = state->Gain[1][k];
+ if(gain > 0.00001f)
+ {
+ for(i = 0;i < td;i++)
+ SamplesOut[k][i+base] += temps[i][1] * gain;
+ }
+ }
+
+ base += td;
+ }
+
+ state->Offset = offset;
+}
+
+static ALeffectStateFactory *ALechoState_getCreator(void)
+{
+ return STATIC_CAST(ALeffectStateFactory, &EchoFactory);
+}
+
+DEFINE_ALEFFECTSTATE_VTABLE(ALechoState);
+
+
+ALeffectState *ALechoStateFactory_create(void)
+{
+ ALechoState *state;
+
+ state = malloc(sizeof(*state));
+ if(!state) return NULL;
+ SET_VTABLE2(ALechoState, ALeffectState, state);
+
+ state->BufferLength = 0;
+ state->SampleBuffer = NULL;
+
+ state->Tap[0].delay = 0;
+ state->Tap[1].delay = 0;
+ state->Offset = 0;
+
+ state->iirFilter.coeff = 0.0f;
+ state->iirFilter.history[0] = 0.0f;
+ state->iirFilter.history[1] = 0.0f;
+
+ return STATIC_CAST(ALeffectState, state);
+}
+
+static ALvoid ALechoStateFactory_destroy(ALeffectState *effect)
+{
+ ALechoState *state = STATIC_UPCAST(ALechoState, ALeffectState, effect);
+ ALechoState_Destruct(state);
+ free(state);
+}
+
+DEFINE_ALEFFECTSTATEFACTORY_VTABLE(ALechoStateFactory);
+
+
+static void init_echo_factory(void)
+{
+ SET_VTABLE2(ALechoStateFactory, ALeffectStateFactory, &EchoFactory);
+}
+
+ALeffectStateFactory *ALechoStateFactory_getFactory(void)
+{
+ static pthread_once_t once = PTHREAD_ONCE_INIT;
+ pthread_once(&once, init_echo_factory);
+ return STATIC_CAST(ALeffectStateFactory, &EchoFactory);
+}
+
+
+void echo_SetParami(ALeffect *effect, ALCcontext *context, ALenum param, ALint val)
+{ (void)effect;(void)param;(void)val; alSetError(context, AL_INVALID_ENUM); }
+void echo_SetParamiv(ALeffect *effect, ALCcontext *context, ALenum param, const ALint *vals)
+{
+ echo_SetParami(effect, context, param, vals[0]);
+}
+void echo_SetParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat val)
+{
+ switch(param)
+ {
+ case AL_ECHO_DELAY:
+ if(val >= AL_ECHO_MIN_DELAY && val <= AL_ECHO_MAX_DELAY)
+ effect->Echo.Delay = val;
+ else
+ alSetError(context, AL_INVALID_VALUE);
+ break;
+
+ case AL_ECHO_LRDELAY:
+ if(val >= AL_ECHO_MIN_LRDELAY && val <= AL_ECHO_MAX_LRDELAY)
+ effect->Echo.LRDelay = val;
+ else
+ alSetError(context, AL_INVALID_VALUE);
+ break;
+
+ case AL_ECHO_DAMPING:
+ if(val >= AL_ECHO_MIN_DAMPING && val <= AL_ECHO_MAX_DAMPING)
+ effect->Echo.Damping = val;
+ else
+ alSetError(context, AL_INVALID_VALUE);
+ break;
+
+ case AL_ECHO_FEEDBACK:
+ if(val >= AL_ECHO_MIN_FEEDBACK && val <= AL_ECHO_MAX_FEEDBACK)
+ effect->Echo.Feedback = val;
+ else
+ alSetError(context, AL_INVALID_VALUE);
+ break;
+
+ case AL_ECHO_SPREAD:
+ if(val >= AL_ECHO_MIN_SPREAD && val <= AL_ECHO_MAX_SPREAD)
+ effect->Echo.Spread = val;
+ else
+ alSetError(context, AL_INVALID_VALUE);
+ break;
+
+ default:
+ alSetError(context, AL_INVALID_ENUM);
+ break;
+ }
+}
+void echo_SetParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals)
+{
+ echo_SetParamf(effect, context, param, vals[0]);
+}
+
+void echo_GetParami(ALeffect *effect, ALCcontext *context, ALenum param, ALint *val)
+{ (void)effect;(void)param;(void)val; alSetError(context, AL_INVALID_ENUM); }
+void echo_GetParamiv(ALeffect *effect, ALCcontext *context, ALenum param, ALint *vals)
+{
+ echo_GetParami(effect, context, param, vals);
+}
+void echo_GetParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *val)
+{
+ switch(param)
+ {
+ case AL_ECHO_DELAY:
+ *val = effect->Echo.Delay;
+ break;
+
+ case AL_ECHO_LRDELAY:
+ *val = effect->Echo.LRDelay;
+ break;
+
+ case AL_ECHO_DAMPING:
+ *val = effect->Echo.Damping;
+ break;
+
+ case AL_ECHO_FEEDBACK:
+ *val = effect->Echo.Feedback;
+ break;
+
+ case AL_ECHO_SPREAD:
+ *val = effect->Echo.Spread;
+ break;
+
+ default:
+ alSetError(context, AL_INVALID_ENUM);
+ break;
+ }
+}
+void echo_GetParamfv(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals)
+{
+ echo_GetParamf(effect, context, param, vals);
+}
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