Atlas - loopwave.c
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[FILE BEGIN]
1/*
2  Copyright (C) 1997-2018 Sam Lantinga <[email protected]>
3
4  This software is provided 'as-is', without any express or implied
5  warranty.  In no event will the authors be held liable for any damages
6  arising from the use of this software.
7
8  Permission is granted to anyone to use this software for any purpose,
9  including commercial applications, and to alter it and redistribute it
10  freely.
11*/
12
13/* Program to load a wave file and loop playing it using SDL audio */
14
15/* loopwaves.c is much more robust in handling WAVE files --
16    This is only for simple WAVEs
17*/
18#include "SDL_config.h"
19
20#include <stdio.h>
21#include <stdlib.h>
22
23#ifdef __EMSCRIPTEN__
24#include <emscripten/emscripten.h>
25#endif
26
27#include "SDL.h"
28
29static struct
30{
31    SDL_AudioSpec spec;
32    Uint8 *sound;               /* Pointer to wave data */
33    Uint32 soundlen;            /* Length of wave data */
34    int soundpos;               /* Current play position */
35} wave;
36
37static SDL_AudioDeviceID device;
38
39/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
40static void
41quit(int rc)
42{
43    SDL_Quit();
44    exit(rc);
45}
46
47static void
48close_audio()
49{
50    if (device != 0) {
51        SDL_CloseAudioDevice(device);
52        device = 0;
53    }
54}
55
56static void
57open_audio()
58{
59    /* Initialize fillerup() variables */
60    device = SDL_OpenAudioDevice(NULL, SDL_FALSE, &wave.spec, NULL, 0);
61    if (!device) {
62        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't open audio: %s\n", SDL_GetError());
63        SDL_FreeWAV(wave.sound);
64        quit(2);
65    }
66
67
68    /* Let the audio run */
69    SDL_PauseAudioDevice(device, SDL_FALSE);
70}
71
72static void reopen_audio()
73{
74    close_audio();
75    open_audio();
76}
77
78
79void SDLCALL
80fillerup(void *unused, Uint8 * stream, int len)
81{
82    Uint8 *waveptr;
83    int waveleft;
84
85    /* Set up the pointers */
86    waveptr = wave.sound + wave.soundpos;
87    waveleft = wave.soundlen - wave.soundpos;
88
89    /* Go! */
90    while (waveleft <= len) {
91        SDL_memcpy(stream, waveptr, waveleft);
92        stream += waveleft;
93        len -= waveleft;
94        waveptr = wave.sound;
95        waveleft = wave.soundlen;
96        wave.soundpos = 0;
97    }
98    SDL_memcpy(stream, waveptr, len);
99    wave.soundpos += len;
100}
101
102static int done = 0;
103
104#ifdef __EMSCRIPTEN__
105void
106loop()
107{
108    if(done || (SDL_GetAudioDeviceStatus(device) != SDL_AUDIO_PLAYING))
109        emscripten_cancel_main_loop();
110}
111#endif
112
113int
114main(int argc, char *argv[])
115{
116    int i;
117    char filename[4096];
118
119    /* Enable standard application logging */
120    SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
121
122    /* Load the SDL library */
123    if (SDL_Init(SDL_INIT_AUDIO|SDL_INIT_EVENTS) < 0) {
124        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
125        return (1);
126    }
127
128    if (argc > 1) {
129        SDL_strlcpy(filename, argv[1], sizeof(filename));
130    } else {
131        SDL_strlcpy(filename, "sample.wav", sizeof(filename));
132    }
133    /* Load the wave file into memory */
134    if (SDL_LoadWAV(filename, &wave.spec, &wave.sound, &wave.soundlen) == NULL) {
135        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s\n", filename, SDL_GetError());
136        quit(1);
137    }
138
139    wave.spec.callback = fillerup;
140
141    /* Show the list of available drivers */
142    SDL_Log("Available audio drivers:");
143    for (i = 0; i < SDL_GetNumAudioDrivers(); ++i) {
144        SDL_Log("%i: %s", i, SDL_GetAudioDriver(i));
145    }
146
147    SDL_Log("Using audio driver: %s\n", SDL_GetCurrentAudioDriver());
148
149    open_audio();
150
151    SDL_FlushEvents(SDL_AUDIODEVICEADDED, SDL_AUDIODEVICEREMOVED);
152
153#ifdef __EMSCRIPTEN__
154    emscripten_set_main_loop(loop, 0, 1);
155#else
156    while (!done) {
157        SDL_Event event;
158
159        while (SDL_PollEvent(&event) > 0) {
160            if (event.type == SDL_QUIT) {
161                done = 1;
162            }
163            if ((event.type == SDL_AUDIODEVICEADDED && !event.adevice.iscapture) ||
164                (event.type == SDL_AUDIODEVICEREMOVED && !event.adevice.iscapture && event.adevice.which == device)) {
165                reopen_audio();
166            }
167        }
168        SDL_Delay(100);
169    }
170#endif
171
172    /* Clean up on signal */
173    close_audio();
174    SDL_FreeWAV(wave.sound);
175    SDL_Quit();
176    return (0);
177}
178
179/* vi: set ts=4 sw=4 expandtab: */
180
[FILE END]
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