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 "alhelpers.h"
  32
  33 #include <stdio.h>
  34 #include <errno.h>
  35 #include <string.h>
  36
  37 #include "AL/al.h"
  38 #include "AL/alc.h"
  39 #include "AL/alext.h"
  40
  41
  42 /* InitAL opens a device and sets up a context using default attributes, making
  43  * the program ready to call OpenAL functions. */
  44 int InitAL(char ***argv, int *argc)
  45 {
  46     const ALCchar *name;
  47     ALCdevice *device;
  48     ALCcontext *ctx;
  49
  50     /* Open and initialize a device */
  51     device = NULL;
  52     if(argc && argv && *argc > 1 && strcmp((*argv)[0], "-device") == 0)
  53     {
  54         device = alcOpenDevice((*argv)[1]);
  55         if(!device)
  56             fprintf(stderr, "Failed to open \"%s\", trying default\n", (*argv)[1]);
  57         (*argv) += 2;
  58         (*argc) -= 2;
  59     }
  60     if(!device)
  61         device = alcOpenDevice(NULL);
  62     if(!device)
  63     {
  64         fprintf(stderr, "Could not open a device!\n");
  65         return 1;
  66     }
  67
  68     ctx = alcCreateContext(device, NULL);
  69     if(ctx == NULL || alcMakeContextCurrent(ctx) == ALC_FALSE)
  70     {
  71         if(ctx != NULL)
  72             alcDestroyContext(ctx);
  73         alcCloseDevice(device);
  74         fprintf(stderr, "Could not set a context!\n");
  75         return 1;
  76     }
  77
  78     name = NULL;
  79     if(alcIsExtensionPresent(device, "ALC_ENUMERATE_ALL_EXT"))
  80         name = alcGetString(device, ALC_ALL_DEVICES_SPECIFIER);
  81     if(!name || alcGetError(device) != AL_NO_ERROR)
  82         name = alcGetString(device, ALC_DEVICE_SPECIFIER);
  83     printf("Opened \"%s\"\n", name);
  84
  85     return 0;
  86 }
  87
  88 /* CloseAL closes the device belonging to the current context, and destroys the
  89  * context. */
  90 void CloseAL(void)
  91 {
  92     ALCdevice *device;
  93     ALCcontext *ctx;
  94
  95     ctx = alcGetCurrentContext();
  96     if(ctx == NULL)
  97         return;
  98
  99     device = alcGetContextsDevice(ctx);
 100
 101     alcMakeContextCurrent(NULL);
 102     alcDestroyContext(ctx);
 103     alcCloseDevice(device);
 104 }
 105
 106
 107 const char *FormatName(ALenum format)
 108 {
 109     switch(format)
 110     {
 111     case AL_FORMAT_MONO8: return "Mono, U8";
 112     case AL_FORMAT_MONO16: return "Mono, S16";
 113     case AL_FORMAT_MONO_FLOAT32: return "Mono, Float32";
 114     case AL_FORMAT_STEREO8: return "Stereo, U8";
 115     case AL_FORMAT_STEREO16: return "Stereo, S16";
 116     case AL_FORMAT_STEREO_FLOAT32: return "Stereo, Float32";
 117     }
 118     return "Unknown Format";
 119 }
 120
 121
 122 #ifdef _WIN32
 123
 124 #define WIN32_LEAN_AND_MEAN
 125 #include <windows.h>
 126 #include <mmsystem.h>
 127
 128 int altime_get(void)
 129 {
 130     static int start_time = 0;
 131     int cur_time;
 132     union {
 133         FILETIME ftime;
 134         ULARGE_INTEGER ulint;
 135     } systime;
 136     GetSystemTimeAsFileTime(&systime.ftime);
 137     /* FILETIME is in 100-nanosecond units, or 1/10th of a microsecond. */
 138     cur_time = (int)(systime.ulint.QuadPart/10000);
 139
 140     if(!start_time)
 141         start_time = cur_time;
 142     return cur_time - start_time;
 143 }
 144
 145 void al_nssleep(unsigned long nsec)
 146 {
 147     Sleep(nsec / 1000000);
 148 }
 149
 150 #else
 151
 152 #include <sys/time.h>
 153 #include <unistd.h>
 154 #include <time.h>
 155
 156 int altime_get(void)
 157 {
 158     static int start_time = 0u;
 159     int cur_time;
 160
 161 #if _POSIX_TIMERS > 0
 162     struct timespec ts;
 163     int ret = clock_gettime(CLOCK_REALTIME, &ts);
 164     if(ret != 0) return 0;
 165     cur_time = (int)(ts.tv_sec*1000 + ts.tv_nsec/1000000);
 166 #else /* _POSIX_TIMERS > 0 */
 167     struct timeval tv;
 168     int ret = gettimeofday(&tv, NULL);
 169     if(ret != 0) return 0;
 170     cur_time = (int)(tv.tv_sec*1000 + tv.tv_usec/1000);
 171 #endif
 172
 173     if(!start_time)
 174         start_time = cur_time;
 175     return cur_time - start_time;
 176 }
 177
 178 void al_nssleep(unsigned long nsec)
 179 {
 180     struct timespec ts, rem;
 181     ts.tv_sec = (time_t)(nsec / 1000000000ul);
 182     ts.tv_nsec = (long)(nsec % 1000000000ul);
 183     while(nanosleep(&ts, &rem) == -1 && errno == EINTR)
 184         ts = rem;
 185 }
 186
 187 #endif