diff options
Diffstat (limited to 'Alc/alcEcho.c')
| -rw-r--r-- | Alc/alcEcho.c | 184 |
1 files changed, 0 insertions, 184 deletions
diff --git a/Alc/alcEcho.c b/Alc/alcEcho.c deleted file mode 100644 index 9ca91747..00000000 --- a/Alc/alcEcho.c +++ /dev/null @@ -1,184 +0,0 @@ -/** - * 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 { - // Must be first in all effects! - ALeffectState state; - - 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; - ALfloat history[2]; -} ALechoState; - -static ALvoid EchoDestroy(ALeffectState *effect) -{ - ALechoState *state = (ALechoState*)effect; - if(state) - { - free(state->SampleBuffer); - state->SampleBuffer = NULL; - free(state); - } -} - -static ALboolean EchoDeviceUpdate(ALeffectState *effect, ALCdevice *Device) -{ - ALechoState *state = (ALechoState*)effect; - 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 EchoUpdate(ALeffectState *effect, ALCdevice *Device, const ALeffectslot *Slot) -{ - ALechoState *state = (ALechoState*)effect; - 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 EchoProcess(ALeffectState *effect, ALuint SamplesToDo, const ALfloat *RESTRICT SamplesIn, ALfloat (*RESTRICT SamplesOut)[BUFFERSIZE]) -{ - ALechoState *state = (ALechoState*)effect; - 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 i, k; - - for(i = 0;i < SamplesToDo;i++,offset++) - { - /* First tap */ - smp = state->SampleBuffer[(offset-tap1) & mask]; - for(k = 0;k < MaxChannels;k++) - SamplesOut[k][i] += smp * state->Gain[0][k]; - - /* Second tap */ - smp = state->SampleBuffer[(offset-tap2) & mask]; - for(k = 0;k < MaxChannels;k++) - SamplesOut[k][i] += smp * state->Gain[1][k]; - - // Apply damping and feedback gain to the second tap, and mix in the - // new sample - smp = lpFilter2P(&state->iirFilter, 0, smp+SamplesIn[i]); - state->SampleBuffer[offset&mask] = smp * state->FeedGain; - } - state->Offset = offset; -} - -ALeffectState *EchoCreate(void) -{ - ALechoState *state; - - state = malloc(sizeof(*state)); - if(!state) - return NULL; - - state->state.Destroy = EchoDestroy; - state->state.DeviceUpdate = EchoDeviceUpdate; - state->state.Update = EchoUpdate; - state->state.Process = EchoProcess; - - 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 &state->state; -} |