1 /*
2 Copyright (C) 1997-2021 Sam Lantinga <slouken@libsdl.org>
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
29 static 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
37 static SDL_AudioDeviceID device;
38
39 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
40 static void
quit(int rc)41 quit(int rc)
42 {
43 SDL_Quit();
44 exit(rc);
45 }
46
47 static void
close_audio()48 close_audio()
49 {
50 if (device != 0) {
51 SDL_CloseAudioDevice(device);
52 device = 0;
53 }
54 }
55
56 static void
open_audio()57 open_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
reopen_audio()72 static void reopen_audio()
73 {
74 close_audio();
75 open_audio();
76 }
77
78
79 void SDLCALL
fillerup(void * unused,Uint8 * stream,int len)80 fillerup(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
102 static int done = 0;
103
104 #ifdef __EMSCRIPTEN__
105 void
loop()106 loop()
107 {
108 if(done || (SDL_GetAudioDeviceStatus(device) != SDL_AUDIO_PLAYING))
109 emscripten_cancel_main_loop();
110 }
111 #endif
112
113 int
main(int argc,char * argv[])114 main(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