misc/libopenalbridge/openalbridge.c
changeset 3514 59dbd31e9953
parent 3513 f589230fa21b
child 3529 0e968ba12a84
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libopenalbridge/openalbridge.c	Thu Jun 17 20:30:39 2010 +0200
@@ -0,0 +1,265 @@
+/*
+* 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 (int memorysize) {
+    ALCcontext *context;
+    ALCdevice *device;
+    int i;
+        
+    // reuse old context and resize the existing 
+    if (openal_ready() == AL_TRUE) {
+        cache_size += memorysize;
+        fprintf(stderr,"(Bridge Info) - already initialized, resizing cache to %d\n", cache_size);
+        the_sounds = (al_sound_t *)Realloc (the_sounds, sizeof(al_sound_t) * cache_size);
+        for (i = cache_size - memorysize; i < cache_size; i++) {
+            the_sounds[i].filename = NULL;
+            the_sounds[i].buffer = -1;
+            the_sounds[i].source_index = -1;
+            the_sounds[i].stats = 0;
+        }
+        instances_number++;
+        return AL_TRUE;
+    }
+    
+    cache_pointer = 0;
+    instances_number++;
+    
+    // set the memory dimentsion and the increment width when reallocating
+    if (memorysize <= 0)
+        cache_size = 50;
+    else
+        cache_size = memorysize;
+
+    // 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].filename = NULL;
+        the_sounds[i].buffer = -1;
+        the_sounds[i].source_index = -1;
+        the_sounds[i].stats = 0;
+    }
+
+    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) {
+        return;
+    }
+    
+    //TODO: free other stuff also
+    for (i = 0; i < cache_size; i++)
+        alDeleteBuffers (1, &the_sounds[i].buffer);
+    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 soundData;
+    int len, i;
+    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 (cache_pointer >= cache_size) {
+        fprintf(stderr,"(Bridge ERROR) - Cache size limit reached; consider allocating more space\n", filename);
+        return -2;
+    }
+    
+    // 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);
+        free(data);
+        return -6;
+    }
+
+    alGenBuffers(1, &soundData.buffer);
+    soundData.filename = filename;
+    soundData.source_index = -1;
+    soundData.stats = 0;
+    
+    if (AL_NO_ERROR != alGetError()) {
+        fprintf(stderr,"(Bridge ERROR) - Failed to allocate memory for buffers\n");
+        return -5;
+    }
+    
+    // copy pcm data in one buffer and free it
+    alBufferData(soundData.buffer, format, data, bitsize, freq);
+    free(data);
+
+    if (AL_NO_ERROR != alGetError()) {
+        fprintf(stderr,"(Bridge ERROR) - Failed to write data to buffers\n");
+        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[cache_pointer] = soundData;
+    return cache_pointer++;
+}