/*
 * pwplib SDL (Simple Directmedia Layer) audio "driver"
 * (C) Copyright 2010 ccr/TNSP^PWP <ccr@tnsp.org>
 *
 * This file and other changes are distributed under same
 * license as pwplib itself.
 */

#include "config.h"

#ifdef DRIVE_SDL

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <SDL.h>

#include "pwplib.h"
#include "gb.h"

#define TIMERHZ 72

static int pwp_sdlaudio_run = 1;
static int pwp_sdlaudio_frag = -1, pwp_sdlaudio_curr;


static void pwp_sdlaudio_fill(void * udata, Uint8 * buf, int len)
{
    (void) udata;
    while (len > 0) {
        if (pwp_sdlaudio_curr >= len) {
            pwp_sdlaudio_curr -= len;
            gb_genwave(buf, len);
            len = 0;
        } else {
            gb_genwave(buf, pwp_sdlaudio_curr);
            buf += pwp_sdlaudio_curr;
            len -= pwp_sdlaudio_curr;
            pwp_sdlaudio_curr = pwp_sdlaudio_frag;
            pwplib.player();
        }
    }
}

static void pwp_sdlaudio_start(void)
{
    if (pwp_sdlaudio_run) {
        pwp_sdlaudio_curr = pwp_sdlaudio_frag;
        pwp_sdlaudio_run = 0;
        pwplib.player();
        SDL_PauseAudio(0);
    }
}

int pwp_sdlaudio_init()
{
    SDL_AudioSpec fmt;

    pwp_sdlaudio_run = 1;

    fmt.freq = 44100;
    fmt.format = AUDIO_U8;
    fmt.channels = 1;
    fmt.samples = 512;
    fmt.callback = pwp_sdlaudio_fill;

    if (SDL_OpenAudio(&fmt, NULL) < 0)
    {
        pwpwrite("* SDL: Could not get desired audio format.\n");
        return 0;
    }

    pwp_sdlaudio_frag = fmt.freq / TIMERHZ;

    pwpwrite("* SDL sound (freq=%d, fmt=%d, chn=%d, buf=%d, frag=%d)\n",
        fmt.freq, fmt.format, fmt.channels, fmt.samples, pwp_sdlaudio_frag);

    pwplib.sound = gb_sound;
    pwplib.loopflush = pwp_sdlaudio_start;
    gb_init(fmt.freq);

    return 1;
}
#endif