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-rw-r--r--Alc/effects/echo.c296
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diff --git a/Alc/effects/echo.c 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 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;
+
+ ALfilterState Filter;
+} 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, gain;
+ ALfloat dirGain;
+
+ state->Tap[0].delay = fastf2u(Slot->EffectProps.Echo.Delay * frequency) + 1;
+ state->Tap[1].delay = fastf2u(Slot->EffectProps.Echo.LRDelay * frequency);
+ state->Tap[1].delay += state->Tap[0].delay;
+
+ lrpan = Slot->EffectProps.Echo.Spread;
+
+ state->FeedGain = Slot->EffectProps.Echo.Feedback;
+
+ ALfilterState_setParams(&state->Filter, ALfilterType_HighShelf,
+ 1.0f - Slot->EffectProps.Echo.Damping,
+ (ALfloat)LOWPASSFREQREF/frequency, 0.0f);
+
+ gain = Slot->Gain;
+ 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 = ALfilterState_processSingle(&state->Filter, temps[i][1]+SamplesIn[i+base]);
+ state->SampleBuffer[offset&mask] = smp * state->FeedGain;
+ offset++;
+ }
+
+ for(k = 0;k < MaxChannels;k++)
+ {
+ ALfloat gain = state->Gain[0][k];
+ if(gain > GAIN_SILENCE_THRESHOLD)
+ {
+ for(i = 0;i < td;i++)
+ SamplesOut[k][i+base] += temps[i][0] * gain;
+ }
+
+ gain = state->Gain[1][k];
+ if(gain > GAIN_SILENCE_THRESHOLD)
+ {
+ for(i = 0;i < td;i++)
+ SamplesOut[k][i+base] += temps[i][1] * gain;
+ }
+ }
+
+ base += td;
+ }
+
+ state->Offset = offset;
+}
+
+static void ALechoState_Delete(ALechoState *state)
+{
+ free(state);
+}
+
+DEFINE_ALEFFECTSTATE_VTABLE(ALechoState);
+
+
+typedef struct ALechoStateFactory {
+ DERIVE_FROM_TYPE(ALeffectStateFactory);
+} ALechoStateFactory;
+
+ALeffectState *ALechoStateFactory_create(ALechoStateFactory *UNUSED(factory))
+{
+ 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;
+
+ ALfilterState_clear(&state->Filter);
+
+ return STATIC_CAST(ALeffectState, state);
+}
+
+DEFINE_ALEFFECTSTATEFACTORY_VTABLE(ALechoStateFactory);
+
+ALeffectStateFactory *ALechoStateFactory_getFactory(void)
+{
+ static ALechoStateFactory EchoFactory = { { GET_VTABLE2(ALechoStateFactory, ALeffectStateFactory) } };
+
+ return STATIC_CAST(ALeffectStateFactory, &EchoFactory);
+}
+
+
+void ALecho_setParami(ALeffect *UNUSED(effect), ALCcontext *context, ALenum UNUSED(param), ALint UNUSED(val))
+{ SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); }
+void ALecho_setParamiv(ALeffect *effect, ALCcontext *context, ALenum param, const ALint *vals)
+{
+ ALecho_setParami(effect, context, param, vals[0]);
+}
+void ALecho_setParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat val)
+{
+ ALeffectProps *props = &effect->Props;
+ switch(param)
+ {
+ case AL_ECHO_DELAY:
+ if(!(val >= AL_ECHO_MIN_DELAY && val <= AL_ECHO_MAX_DELAY))
+ SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
+ props->Echo.Delay = val;
+ break;
+
+ case AL_ECHO_LRDELAY:
+ if(!(val >= AL_ECHO_MIN_LRDELAY && val <= AL_ECHO_MAX_LRDELAY))
+ SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
+ props->Echo.LRDelay = val;
+ break;
+
+ case AL_ECHO_DAMPING:
+ if(!(val >= AL_ECHO_MIN_DAMPING && val <= AL_ECHO_MAX_DAMPING))
+ SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
+ props->Echo.Damping = val;
+ break;
+
+ case AL_ECHO_FEEDBACK:
+ if(!(val >= AL_ECHO_MIN_FEEDBACK && val <= AL_ECHO_MAX_FEEDBACK))
+ SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
+ props->Echo.Feedback = val;
+ break;
+
+ case AL_ECHO_SPREAD:
+ if(!(val >= AL_ECHO_MIN_SPREAD && val <= AL_ECHO_MAX_SPREAD))
+ SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
+ props->Echo.Spread = val;
+ break;
+
+ default:
+ SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
+ }
+}
+void ALecho_setParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals)
+{
+ ALecho_setParamf(effect, context, param, vals[0]);
+}
+
+void ALecho_getParami(const ALeffect *UNUSED(effect), ALCcontext *context, ALenum UNUSED(param), ALint *UNUSED(val))
+{ SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); }
+void ALecho_getParamiv(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *vals)
+{
+ ALecho_getParami(effect, context, param, vals);
+}
+void ALecho_getParamf(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *val)
+{
+ const ALeffectProps *props = &effect->Props;
+ switch(param)
+ {
+ case AL_ECHO_DELAY:
+ *val = props->Echo.Delay;
+ break;
+
+ case AL_ECHO_LRDELAY:
+ *val = props->Echo.LRDelay;
+ break;
+
+ case AL_ECHO_DAMPING:
+ *val = props->Echo.Damping;
+ break;
+
+ case AL_ECHO_FEEDBACK:
+ *val = props->Echo.Feedback;
+ break;
+
+ case AL_ECHO_SPREAD:
+ *val = props->Echo.Spread;
+ break;
+
+ default:
+ SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
+ }
+}
+void ALecho_getParamfv(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals)
+{
+ ALecho_getParamf(effect, context, param, vals);
+}
+
+DEFINE_ALEFFECT_VTABLE(ALecho);
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