I'll learn to build first eventually...
/*
* OpenAL Bridge - a simple portable library for OpenAL interface
* Copyright (c) 2009 Vittorio Giovara <vittorio.giovara@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; version 2 of the License
*
* This program 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include "openalbridge.h"
#include "globals.h"
#include "al.h"
#include "alc.h"
#include "wrappers.h"
#include "loaders.h"
#include "string.h"
// Sources are points emitting sound, their number is limited, but a single source can play many buffers
// Buffers hold sound data and are unlimited
ALuint *Sources;
ALuint cache_size, cache_index, sources_number;
ALboolean instances_number;
al_sound_t *the_sounds;
ALint cache_pointer;
// Initialize an OpenAL contex and allocate memory space for data and buffers
// It can be called twice to increase the cache size
int openal_init (void) {
ALCcontext *context;
ALCdevice *device;
int i;
// reuse old context and resize the existing
if (openal_ready() == AL_TRUE) {
fprintf(stderr,"(Bridge Info) - already initialized\n");
instances_number++;
return AL_TRUE;
}
cache_pointer = 0;
instances_number++;
// initial memory size
cache_size = 50;
// open hardware device if present
device = alcOpenDevice(NULL);
sources_number = 16;
if (device == NULL) {
fprintf(stderr,"(Bridge Warning) - failed to open sound device, using software renderer\n");
device = alcOpenDevice("Generic Software");
sources_number = 32;
if (device == NULL) {
fprintf(stderr,"(Bridge ERROR) - failed to start software renderer, sound will be disabled\n");
return -1;
}
}
fprintf(stderr,"(Bridge Info) - output device: %s\n", alcGetString(device, ALC_DEVICE_SPECIFIER));
context = alcCreateContext(device, NULL);
alcMakeContextCurrent(context);
alcProcessContext(context);
if (AL_NO_ERROR != alGetError()) {
fprintf(stderr,"(Bridge ERROR) - Failed to create a new contex\n");
alcMakeContextCurrent(NULL);
alcDestroyContext(context);
alcCloseDevice(device);
return -2;
}
Sources = (ALuint *)Malloc (sizeof(ALuint) * sources_number);
alGenSources(sources_number, Sources);
// set the listener gain, position (on xyz axes), velocity (one value for each axe) and orientation
// Position, Velocity and Orientation of the listener
ALfloat ListenerPos[] = {0.0, 0.0, 0.0};
ALfloat ListenerVel[] = {0.0, 0.0, 0.0};
ALfloat ListenerOri[] = {0.0, 0.0, -1.0, 0.0, 1.0, 0.0};
alListenerf (AL_GAIN, 1.0f );
alListenerfv(AL_POSITION, ListenerPos);
alListenerfv(AL_VELOCITY, ListenerVel);
alListenerfv(AL_ORIENTATION, ListenerOri);
if (AL_NO_ERROR != alGetError()) {
fprintf(stderr,"(Bridge ERROR) - Failed to set Listener properties\n");
return -3;
}
the_sounds = (al_sound_t *)Malloc (sizeof(al_sound_t) * cache_size);
for (i = 0; i < cache_size; i++)
the_sounds[i] = new_sound_el();
alGetError();
return AL_TRUE;
}
// Stop all sounds, deallocate all memory and close OpenAL context
void openal_close (void) {
ALCcontext *context;
ALCdevice *device;
int i;
if (instances_number == 0) {
fprintf(stderr,"(Bridge Warning) - OpenAL not initialized\n");
return;
}
instances_number--;
if (instances_number > 0) {
// release memory only when last session ends
return;
}
for (i = 0; i < cache_size; i++) {
openal_unloadfile(i);
}
free(the_sounds);
alSourceStopv (sources_number, Sources);
alDeleteSources (sources_number, Sources);
free(Sources);
context = alcGetCurrentContext();
device = alcGetContextsDevice(context);
alcMakeContextCurrent(NULL);
alcDestroyContext(context);
alcCloseDevice(device);
fprintf(stderr,"(Bridge Info) - closed\n");
return;
}
ALboolean openal_ready (void) {
if (instances_number >= 1)
return AL_TRUE;
else
return AL_FALSE;
}
// Open a file, load into memory and allocate the Source buffer for playing
int openal_loadfile (const char *filename){
ALenum format, error;
ALsizei bitsize, freq;
uint32_t fileformat;
al_sound_t sound_data;
int len, i, index = -1;
char *data;
FILE *fp;
if (openal_ready() == AL_FALSE) {
fprintf(stderr,"(Bridge Warning) - not initialized\n");
return -1;
}
// if this sound is already loaded return the index from the_sounds
len = strlen(filename);
for (i = 0; i < cache_size; i++) {
if (the_sounds[i].filename != NULL && strncmp(the_sounds[i].filename, filename, len) == 0) {
#ifdef DEBUG
fprintf(stderr,"(Bridge Debug) - sound %d is already loaded\n", i);
#endif
return i;
}
// if we don't have memory available search for a free element
if (cache_pointer >= cache_size)
if (the_sounds[i].is_used == AL_FALSE)
index = i;
}
if (index == -1 && cache_pointer >= cache_size) {
fprintf(stderr,"(Bridge Info) - No free spots found; doubling cache size\n", filename);
cache_size *= 2;
the_sounds = (al_sound_t *)Realloc (the_sounds, sizeof(al_sound_t) * cache_size);
for (i = cache_size - 50; i < cache_size; i++)
the_sounds[i] = new_sound_el();
} else
index = ++cache_pointer;
// detect the file format, as written in the first 4 bytes of the header
fp = Fopen (filename, "rb");
if (fp == NULL) {
fprintf(stderr,"(Bridge ERROR) - File %s not loaded\n", filename);
return -3;
}
error = fread (&fileformat, sizeof(uint32_t), 1, fp);
fclose (fp);
if (error < 0) {
fprintf(stderr,"(Bridge ERROR) - File %s is too short\n", filename);
return -4;
}
switch (ENDIAN_BIG_32(fileformat)) {
case OGG_FILE_FORMAT:
error = load_oggvorbis (filename, &format, &data, &bitsize, &freq);
break;
case WAV_FILE_FORMAT:
error = load_wavpcm (filename, &format, &data, &bitsize, &freq);
break;
default:
fprintf(stderr,"(Bridge ERROR) - File format (%08X) not supported\n", ENDIAN_BIG_32(fileformat));
return -5;
break;
}
if (error != 0) {
fprintf(stderr,"(Bridge ERROR) - error loading file %s\n", filename);
if(data)
free(data);
return -6;
}
// alGenBuffers happens here
sound_data = init_sound_el(filename);
if (AL_NO_ERROR != alGetError()) {
fprintf(stderr,"(Bridge ERROR) - Failed to allocate memory for buffer %d\n", index);
free(data);
return -5;
}
// copy pcm data in one buffer and free it
alBufferData(sound_data.buffer, format, data, bitsize, freq);
free(data);
if (AL_NO_ERROR != alGetError()) {
fprintf(stderr,"(Bridge ERROR) - Failed to write data to buffer %d\n", index);
return -8;
}
// clear any AL errors beforehand
alGetError();
fprintf(stderr,"(Bridge Info) - successfully loaded %s\n", filename);
// returns the index of the source you just loaded, increments it and exits
the_sounds[index] = sound_data;
return index;
}
void openal_unloadfile (uint32_t index) {
ALint state;
if (openal_ready() == AL_TRUE && index < cache_size && the_sounds[index].is_used == AL_TRUE) {
alGetSourcei (Sources[the_sounds[index].source_index], AL_SOURCE_STATE, &state);
if (state == AL_PLAYING || state == AL_PAUSED)
openal_stopsound(index);
// free memory and
alDeleteBuffers (1, &the_sounds[index].buffer);
the_sounds[index] = new_sound_el();
}
}