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, ALCcontext *Context, const ALeffectslot *Slot)
  54 {
  55     ALdedicatedState *state = (ALdedicatedState*)effect;
  56     ALCdevice *device = Context->Device;
  57     const ALfloat *SpeakerGain;
  58     ALfloat Gain;
  59     ALint pos;
  60     ALsizei s;
  61
  62     Gain = Slot->Gain * Slot->effect.Dedicated.Gain;
  63     for(s = 0;s < MAXCHANNELS;s++)
  64         state->gains[s] = 0.0f;
  65
  66     if(Slot->effect.type == AL_EFFECT_DEDICATED_DIALOGUE)
  67     {
  68         pos = aluCart2LUTpos(1.0f, 0.0f);
  69         SpeakerGain = device->PanningLUT[pos];
  70
  71         for(s = 0;s < MAXCHANNELS;s++)
  72             state->gains[s] = SpeakerGain[s] * Gain;
  73     }
  74     else if(Slot->effect.type == AL_EFFECT_DEDICATED_LOW_FREQUENCY_EFFECT)
  75         state->gains[LFE] = Gain;
  76 }
  77
  78 static ALvoid DedicatedProcess(ALeffectState *effect, const ALeffectslot *Slot, ALuint SamplesToDo, const ALfloat *SamplesIn, ALfloat (*SamplesOut)[MAXCHANNELS])
  79 {
  80     ALdedicatedState *state = (ALdedicatedState*)effect;
  81     const ALfloat *gains = state->gains;
  82     ALuint i, s;
  83     (void)Slot;
  84
  85     for(i = 0;i < SamplesToDo;i++)
  86     {
  87         ALfloat sample;
  88
  89         sample = SamplesIn[i];
  90         for(s = 0;s < MAXCHANNELS;s++)
  91             SamplesOut[i][s] = sample * gains[s];
  92     }
  93 }
  94
  95 ALeffectState *DedicatedCreate(void)
  96 {
  97     ALdedicatedState *state;
  98     ALsizei s;
  99
 100     state = malloc(sizeof(*state));
 101     if(!state)
 102         return NULL;
 103
 104     state->state.Destroy = DedicatedDestroy;
 105     state->state.DeviceUpdate = DedicatedDeviceUpdate;
 106     state->state.Update = DedicatedUpdate;
 107     state->state.Process = DedicatedProcess;
 108
 109     for(s = 0;s < MAXCHANNELS;s++)
 110         state->gains[s] = 0.0f;
 111
 112     return &state->state;
 113 }