view test/loopwave.c @ 3473:7bdc10624cba

This is terrible, but the OpenGL standard says that lines are half open, which means that one endpoint is not covered so adjoining lines don't overlap. It also doesn't define which end is open, and indeed Mac OS X and Linux differ. Mac OS X seems to leave the second endpoint open, but Linux uses the right-most endpoint for x major lines and the bottom-most endpoint for y major lines.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 21 Nov 2009 07:14:21 +0000
parents dc6384958091
children 6e70cf55a368
line wrap: on
line source


/* Program to load a wave file and loop playing it using SDL sound */

/* 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>

#if HAVE_SIGNAL_H
#include <signal.h>
#endif

#include "SDL.h"
#include "SDL_audio.h"

struct
{
    SDL_AudioSpec spec;
    Uint8 *sound;               /* Pointer to wave data */
    Uint32 soundlen;            /* Length of wave data */
    int soundpos;               /* Current play position */
} wave;


/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
static void
quit(int rc)
{
    SDL_Quit();
    exit(rc);
}


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;
void
poked(int sig)
{
    done = 1;
}

int
main(int argc, char *argv[])
{
    /* Load the SDL library */
    if (SDL_Init(SDL_INIT_AUDIO) < 0) {
        fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError());
        return (1);
    }

    if (argv[1] == NULL) {
        argv[1] = "sample.wav";
    }
    /* Load the wave file into memory */
    if (SDL_LoadWAV(argv[1], &wave.spec, &wave.sound, &wave.soundlen) == NULL) {
        fprintf(stderr, "Couldn't load %s: %s\n", argv[1], SDL_GetError());
        quit(1);
    }

    wave.spec.callback = fillerup;
#if HAVE_SIGNAL_H
    /* Set the signals */
#ifdef SIGHUP
    signal(SIGHUP, poked);
#endif
    signal(SIGINT, poked);
#ifdef SIGQUIT
    signal(SIGQUIT, poked);
#endif
    signal(SIGTERM, poked);
#endif /* HAVE_SIGNAL_H */

    /* Initialize fillerup() variables */
    if (SDL_OpenAudio(&wave.spec, NULL) < 0) {
        fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError());
        SDL_FreeWAV(wave.sound);
        quit(2);
    }

    /* Right now we're using the 1.2 SDL_OpenAudio(), but if we move to the
       1.3 device enumeration version, we shouldn't hardcore device id #1 for
       SDL_GetAudioDeviceName(), below. */
    printf("Using audio driver: %s\n", SDL_GetCurrentAudioDriver());
    printf("Using audio device: %s\n", SDL_GetAudioDeviceName(1, 0));

    /* Let the audio run */
    SDL_PauseAudio(0);
    while (!done && (SDL_GetAudioStatus() == SDL_AUDIO_PLAYING))
        SDL_Delay(1000);

    /* Clean up on signal */
    SDL_CloseAudio();
    SDL_FreeWAV(wave.sound);
    SDL_Quit();
    return (0);
}