examples/common/alhelpers.h

   1 #ifndef ALHELPERS_H
   2 #define ALHELPERS_H
   3
   4 #include "AL/al.h"
   5 #include "AL/alc.h"
   6
   7 #ifdef __cplusplus
   8 extern "C" {
   9 #endif
  10
  11 /* Some helper functions to get the name from the format enums. */
  12 const char *FormatName(ALenum format);
  13
  14 /* Easy device init/deinit functions. InitAL returns 0 on success. */
  15 int InitAL(char ***argv, int *argc);
  16 void CloseAL(void);
  17
  18 /* Cross-platform timeget and sleep functions. */
  19 int altime_get(void);
  20 void al_nssleep(unsigned long nsec);
  21
  22 /* C doesn't allow casting between function and non-function pointer types, so
  23  * with C99 we need to use a union to reinterpret the pointer type. Pre-C99
  24  * still needs to use a normal cast and live with the warning (C++ is fine with
  25  * a regular reinterpret_cast).
  26  */
  27 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
  28 #define FUNCTION_CAST(T, ptr) (union{void *p; T f;}){ptr}.f
  29 #elif defined(__cplusplus)
  30 #define FUNCTION_CAST(T, ptr) reinterpret_cast<T>(ptr)
  31 #else
  32 #define FUNCTION_CAST(T, ptr) (T)(ptr)
  33 #endif
  34
  35 #ifdef __cplusplus
  36 } // extern "C"
  37
  38 #include <cstdio>
  39 #include <iostream>
  40 #include <string>
  41 #include <string_view>
  42
  43 #include "alspan.h"
  44
  45 int InitAL(al::span<std::string_view> &args)
  46 {
  47     ALCdevice *device{};
  48
  49     /* Open and initialize a device */
  50     if(args.size() > 1 && args[0] == "-device")
  51     {
  52         device = alcOpenDevice(std::string{args[1]}.c_str());
  53         if(!device)
  54             std::cerr<< "Failed to open \""<<args[1]<<"\", trying default\n";
  55         args = args.subspan(2);
  56     }
  57     if(!device)
  58         device = alcOpenDevice(nullptr);
  59     if(!device)
  60     {
  61         std::fprintf(stderr, "Could not open a device!\n");
  62         return 1;
  63     }
  64
  65     ALCcontext *ctx{alcCreateContext(device, nullptr)};
  66     if(!ctx || alcMakeContextCurrent(ctx) == ALC_FALSE)
  67     {
  68         if(ctx)
  69             alcDestroyContext(ctx);
  70         alcCloseDevice(device);
  71         std::fprintf(stderr, "Could not set a context!\n");
  72         return 1;
  73     }
  74
  75     const ALCchar *name{};
  76     if(alcIsExtensionPresent(device, "ALC_ENUMERATE_ALL_EXT"))
  77         name = alcGetString(device, ALC_ALL_DEVICES_SPECIFIER);
  78     if(!name || alcGetError(device) != AL_NO_ERROR)
  79         name = alcGetString(device, ALC_DEVICE_SPECIFIER);
  80     std::printf("Opened \"%s\"\n", name);
  81
  82     return 0;
  83 }
  84
  85 #endif
  86
  87 #endif /* ALHELPERS_H */