/* Copyright (C) 1997-2022 Sam Lantinga <slouken@libsdl.org> This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software. Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely. */ /* Program to load a wave file and loop playing it using SDL audio */ /* loopwaves.c is much more robust in handling WAVE files -- This is only for simple WAVEs */ #include "SDL_config.h" #include <stdio.h> #include <stdlib.h> #ifdef __EMSCRIPTEN__ #include <emscripten/emscripten.h> #endif #include "SDL.h" static struct { SDL_AudioSpec spec; Uint8 *sound; /* Pointer to wave data */ Uint32 soundlen; /* Length of wave data */ int soundpos; /* Current play position */ } wave; static SDL_AudioDeviceID device; /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */ static void quit(int rc) { SDL_Quit(); exit(rc); } static void close_audio() { if (device != 0) { SDL_CloseAudioDevice(device); device = 0; } } static void open_audio() { /* Initialize fillerup() variables */ device = SDL_OpenAudioDevice(NULL, SDL_FALSE, &wave.spec, NULL, 0); if (!device) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't open audio: %s\n", SDL_GetError()); SDL_FreeWAV(wave.sound); quit(2); } /* Let the audio run */ SDL_PauseAudioDevice(device, SDL_FALSE); } static void reopen_audio() { close_audio(); open_audio(); } void SDLCALL fillerup(void *unused, Uint8 * stream, int len) { Uint8 *waveptr; int waveleft; /* Set up the pointers */ waveptr = wave.sound + wave.soundpos; waveleft = wave.soundlen - wave.soundpos; /* Go! */ while (waveleft <= len) { SDL_memcpy(stream, waveptr, waveleft); stream += waveleft; len -= waveleft; waveptr = wave.sound; waveleft = wave.soundlen; wave.soundpos = 0; } SDL_memcpy(stream, waveptr, len); wave.soundpos += len; } static int done = 0; #ifdef __EMSCRIPTEN__ void loop() { if(done || (SDL_GetAudioDeviceStatus(device) != SDL_AUDIO_PLAYING)) emscripten_cancel_main_loop(); } #endif int main(int argc, char *argv[]) { int i; char filename[4096]; /* Enable standard application logging */ SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO); /* Load the SDL library */ if (SDL_Init(SDL_INIT_AUDIO|SDL_INIT_EVENTS) < 0) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError()); return (1); } if (argc > 1) { SDL_strlcpy(filename, argv[1], sizeof(filename)); } else { SDL_strlcpy(filename, "sample.wav", sizeof(filename)); } /* Load the wave file into memory */ if (SDL_LoadWAV(filename, &wave.spec, &wave.sound, &wave.soundlen) == NULL) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s\n", filename, SDL_GetError()); quit(1); } wave.spec.callback = fillerup; /* Show the list of available drivers */ SDL_Log("Available audio drivers:"); for (i = 0; i < SDL_GetNumAudioDrivers(); ++i) { SDL_Log("%i: %s", i, SDL_GetAudioDriver(i)); } SDL_Log("Using audio driver: %s\n", SDL_GetCurrentAudioDriver()); open_audio(); SDL_FlushEvents(SDL_AUDIODEVICEADDED, SDL_AUDIODEVICEREMOVED); #ifdef __EMSCRIPTEN__ emscripten_set_main_loop(loop, 0, 1); #else while (!done) { SDL_Event event; while (SDL_PollEvent(&event) > 0) { if (event.type == SDL_QUIT) { done = 1; } if ((event.type == SDL_AUDIODEVICEADDED && !event.adevice.iscapture) || (event.type == SDL_AUDIODEVICEREMOVED && !event.adevice.iscapture && event.adevice.which == device)) { reopen_audio(); } } SDL_Delay(100); } #endif /* Clean up on signal */ close_audio(); SDL_FreeWAV(wave.sound); SDL_Quit(); return (0); } /* vi: set ts=4 sw=4 expandtab: */