examples/common/alhelpers.c

   1 /*
   2  * OpenAL Helpers
   3  *
   4  * Copyright (c) 2011 by Chris Robinson <chris.kcat@gmail.com>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 /* This file contains routines to help with some menial OpenAL-related tasks,
  26  * such as opening a device and setting up a context, closing the device and
  27  * destroying its context, converting between frame counts and byte lengths,
  28  * finding an appropriate buffer format, and getting readable strings for
  29  * channel configs and sample types. */
  30
  31 #include <stdio.h>
  32 #include <string.h>
  33
  34 #include "AL/al.h"
  35 #include "AL/alc.h"
  36 #include "AL/alext.h"
  37
  38 #include "alhelpers.h"
  39
  40
  41 /* InitAL opens a device and sets up a context using default attributes, making
  42  * the program ready to call OpenAL functions. */
  43 int InitAL(char ***argv, int *argc)
  44 {
  45     const ALCchar *name;
  46     ALCdevice *device;
  47     ALCcontext *ctx;
  48
  49     /* Open and initialize a device */
  50     device = NULL;
  51     if(argc && argv && *argc > 1 && strcmp((*argv)[0], "-device") == 0)
  52     {
  53         device = alcOpenDevice((*argv)[1]);
  54         if(!device)
  55             fprintf(stderr, "Failed to open \"%s\", trying default\n", (*argv)[1]);
  56         (*argv) += 2;
  57         (*argc) -= 2;
  58     }
  59     if(!device)
  60         device = alcOpenDevice(NULL);
  61     if(!device)
  62     {
  63         fprintf(stderr, "Could not open a device!\n");
  64         return 1;
  65     }
  66
  67     ctx = alcCreateContext(device, NULL);
  68     if(ctx == NULL || alcMakeContextCurrent(ctx) == ALC_FALSE)
  69     {
  70         if(ctx != NULL)
  71             alcDestroyContext(ctx);
  72         alcCloseDevice(device);
  73         fprintf(stderr, "Could not set a context!\n");
  74         return 1;
  75     }
  76
  77     name = NULL;
  78     if(alcIsExtensionPresent(device, "ALC_ENUMERATE_ALL_EXT"))
  79         name = alcGetString(device, ALC_ALL_DEVICES_SPECIFIER);
  80     if(!name || alcGetError(device) != AL_NO_ERROR)
  81         name = alcGetString(device, ALC_DEVICE_SPECIFIER);
  82     printf("Opened \"%s\"\n", name);
  83
  84     return 0;
  85 }
  86
  87 /* CloseAL closes the device belonging to the current context, and destroys the
  88  * context. */
  89 void CloseAL(void)
  90 {
  91     ALCdevice *device;
  92     ALCcontext *ctx;
  93
  94     ctx = alcGetCurrentContext();
  95     if(ctx == NULL)
  96         return;
  97
  98     device = alcGetContextsDevice(ctx);
  99
 100     alcMakeContextCurrent(NULL);
 101     alcDestroyContext(ctx);
 102     alcCloseDevice(device);
 103 }
 104
 105
 106 const char *FormatName(ALenum format)
 107 {
 108     switch(format)
 109     {
 110         case AL_FORMAT_MONO8: return "Mono, U8";
 111         case AL_FORMAT_MONO16: return "Mono, S16";
 112         case AL_FORMAT_STEREO8: return "Stereo, U8";
 113         case AL_FORMAT_STEREO16: return "Stereo, S16";
 114     }
 115     return "Unknown Format";
 116 }