Alc/alcDedicated.c

   1 /**
   2  * OpenAL cross platform audio library
   3  * Copyright (C) 2011 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., 59 Temple Place - Suite 330,
  17  *  Boston, MA  02111-1307, USA.
  18  * Or go to http://www.gnu.org/copyleft/lgpl.html
  19  */
  20
  21 #include "config.h"
  22
  23 #include <stdlib.h>
  24
  25 #include "alMain.h"
  26 #include "alFilter.h"
  27 #include "alAuxEffectSlot.h"
  28 #include "alError.h"
  29 #include "alu.h"
  30
  31
  32 typedef struct ALdedicatedState {
  33     // Must be first in all effects!
  34     ALeffectState state;
  35
  36     ALfloat gains[MaxChannels];
  37 } ALdedicatedState;
  38
  39
  40 static ALvoid DedicatedDestroy(ALeffectState *effect)
  41 {
  42     ALdedicatedState *state = (ALdedicatedState*)effect;
  43     free(state);
  44 }
  45
  46 static ALboolean DedicatedDeviceUpdate(ALeffectState *effect, ALCdevice *Device)
  47 {
  48     (void)effect;
  49     (void)Device;
  50     return AL_TRUE;
  51 }
  52
  53 static ALvoid DedicatedUpdate(ALeffectState *effect, ALCdevice *device, const ALeffectslot *Slot)
  54 {
  55     ALdedicatedState *state = (ALdedicatedState*)effect;
  56     ALfloat Gain;
  57     ALsizei s;
  58
  59     Gain = Slot->Gain * Slot->effect.Dedicated.Gain;
  60     for(s = 0;s < MaxChannels;s++)
  61         state->gains[s] = 0.0f;
  62
  63     if(Slot->effect.type == AL_EFFECT_DEDICATED_DIALOGUE)
  64         ComputeAngleGains(device, atan2f(0.0f, 1.0f), 0.0f, Gain, state->gains);
  65     else if(Slot->effect.type == AL_EFFECT_DEDICATED_LOW_FREQUENCY_EFFECT)
  66         state->gains[LFE] = Gain;
  67 }
  68
  69 static ALvoid DedicatedProcess(ALeffectState *effect, ALuint SamplesToDo, const ALfloat *SamplesIn, ALfloat (*SamplesOut)[MaxChannels])
  70 {
  71     ALdedicatedState *state = (ALdedicatedState*)effect;
  72     const ALfloat *gains = state->gains;
  73     ALuint i, s;
  74
  75     for(i = 0;i < SamplesToDo;i++)
  76     {
  77         ALfloat sample;
  78
  79         sample = SamplesIn[i];
  80         for(s = 0;s < MaxChannels;s++)
  81             SamplesOut[i][s] = sample * gains[s];
  82     }
  83 }
  84
  85 ALeffectState *DedicatedCreate(void)
  86 {
  87     ALdedicatedState *state;
  88     ALsizei s;
  89
  90     state = malloc(sizeof(*state));
  91     if(!state)
  92         return NULL;
  93
  94     state->state.Destroy = DedicatedDestroy;
  95     state->state.DeviceUpdate = DedicatedDeviceUpdate;
  96     state->state.Update = DedicatedUpdate;
  97     state->state.Process = DedicatedProcess;
  98
  99     for(s = 0;s < MaxChannels;s++)
 100         state->gains[s] = 0.0f;
 101
 102     return &state->state;
 103 }