/*
 * Copyright (C) 1996-1997 Id Software, Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.
 *
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 */
// snd_mem.c: sound caching

#include "quakedef.h"

int           cache_full_cycle;

byte         *S_Alloc (int size);

/*
 * ResampleSfx
 */
void ResampleSfx (sfx_t * sfx, int inrate, int inwidth, byte * data) {
    int           outcount;
    int           srcsample;
    float         stepscale;
    int           i;
    int           sample, samplefrac, fracstep;
    sfxcache_t   *sc;

    sc = Cache_Check (&sfx->cache);
    if (!sc)
        return;

    stepscale = (float) inrate / shm->speed;    // this is usually 0.5, 1, or 2

    outcount = sc->length / stepscale;
    sc->length = outcount;
    if (sc->loopstart != -1)
        sc->loopstart = sc->loopstart / stepscale;

    sc->speed = shm->speed;
    if (s_loadas8bit.value)
        sc->width = 1;
    else
        sc->width = inwidth;
    sc->stereo = 0;

    // resample / decimate to the current source rate

    if (stepscale == 1 && inwidth == 1 && sc->width == 1) {
        // fast special case
        for (i = 0; i < outcount; i++)
            ((signed char *) sc->data)[i] = (int) ((unsigned char) (data[i]) - 128);
    } else {
        // general case
        samplefrac = 0;
        fracstep = stepscale * 256;
        for (i = 0; i < outcount; i++) {
            srcsample = samplefrac >> 8;
            samplefrac += fracstep;
            if (inwidth == 2)
                sample = LittleShort (((short *) data)[srcsample]);
            else
                sample = (int) ((unsigned char) (data[srcsample]) - 128) << 8;
            if (sc->width == 2)
                ((short *) sc->data)[i] = sample;
            else
                ((signed char *) sc->data)[i] = sample >> 8;
        }
    }
}

// 

/*
 * S_LoadSound
 */
sfxcache_t   *S_LoadSound (sfx_t * s) {
    char          namebuffer[256];
    byte         *data;
    wavinfo_t     info;
    int           len;
    float         stepscale;
    sfxcache_t   *sc;
    byte          stackbuf[1 * 1024];  // avoid dirtying the cache heap

    // see if still in memory
    if ((sc = Cache_Check (&s->cache)))
        return sc;

    // Con_Printf ("S_LoadSound: %x\n", (int)stackbuf);
    // load it in
    Q_strcpy (namebuffer, "sound/");
    strcat (namebuffer, s->name);

    // Con_Printf ("loading %s\n",namebuffer);

    if (!(data = COM_LoadStackFile (namebuffer, stackbuf, sizeof (stackbuf)))) {
        Con_Printf ("Couldn't load %s\n", namebuffer);
        return NULL;
    }

    info = GetWavinfo (s->name, data, com_filesize);
    if (info.channels != 1) {
        Con_Printf ("%s is a stereo sample\n", s->name);
        return NULL;
    }

    stepscale = (float) info.rate / shm->speed;
    len = info.samples / stepscale;

    len = len * info.width * info.channels;

    sc = Cache_Alloc (&s->cache, len + sizeof (sfxcache_t), s->name);
    if (!sc)
        return NULL;

    sc->length = info.samples;
    sc->loopstart = info.loopstart;
    sc->speed = info.rate;
    sc->width = info.width;
    sc->stereo = info.channels;

    ResampleSfx (s, sc->speed, sc->width, data + info.dataofs);

    return sc;
}

/*
 *
 *
 * WAV loading
 *
 *
 */

byte         *data_p;
byte         *iff_end;
byte         *last_chunk;
byte         *iff_data;
int           iff_chunk_len;

short GetLittleShort (void) {
    short         val = 0;
    val = *data_p;
    val = val + (*(data_p + 1) << 8);
    data_p += 2;
    return val;
}

int GetLittleLong (void) {
    int           val = 0;
    val = *data_p;
    val = val + (*(data_p + 1) << 8);
    val = val + (*(data_p + 2) << 16);
    val = val + (*(data_p + 3) << 24);
    data_p += 4;
    return val;
}

void FindNextChunk (char *name) {
    while (1) {
        data_p = last_chunk;

        if (data_p >= iff_end) {       // didn't find the chunk
            data_p = NULL;
            return;
        }

        data_p += 4;
        iff_chunk_len = GetLittleLong ();
        if (iff_chunk_len < 0) {
            data_p = NULL;
            return;
        }
        // if (iff_chunk_len > 1024*1024)
        // Sys_Error ("FindNextChunk: %i length is past the 1 meg sanity
        // limit", iff_chunk_len);
        data_p -= 8;
        last_chunk = data_p + 8 + ((iff_chunk_len + 1) & ~1);
        if (!strncmp ((char *) data_p, name, 4))        // lxndr: cast added
            return;
    }
}

void FindChunk (char *name) {
    last_chunk = iff_data;
    FindNextChunk (name);
}

void DumpChunks (void) {
    char          str[5];

    str[4] = 0;
    data_p = iff_data;
    do {
        memcpy (str, data_p, 4);
        data_p += 4;
        iff_chunk_len = GetLittleLong ();
        Con_Printf ("0x%x : %s (%d)\n", (int) (data_p - 4), str, iff_chunk_len);
        data_p += (iff_chunk_len + 1) & ~1;
    }
    while (data_p < iff_end);
}

/*
 * GetWavinfo
 */
wavinfo_t GetWavinfo (char *name, byte * wav, int wavlength) {
    wavinfo_t     info;
    int           i;
    int           format;
    int           samples;

    memset (&info, 0, sizeof (info));

    if (!wav)
        return info;

    iff_data = wav;
    iff_end = wav + wavlength;

    // find "RIFF" chunk
    FindChunk ("RIFF");
    if (!(data_p && !strncmp ((char *) data_p + 8, "WAVE", 4))) {       // lxndr: cast added
        Con_Printf ("Missing RIFF/WAVE chunks\n");
        return info;
    }
    // get "fmt " chunk
    iff_data = data_p + 12;
    // DumpChunks ();

    FindChunk ("fmt ");
    if (!data_p) {
        Con_Printf ("Missing fmt chunk\n");
        return info;
    }
    data_p += 8;
    format = GetLittleShort ();
    if (format != 1) {
        Con_Printf ("Microsoft PCM format only\n");
        return info;
    }

    info.channels = GetLittleShort ();
    info.rate = GetLittleLong ();
    data_p += 4 + 2;
    info.width = GetLittleShort () / 8;

    // get cue chunk
    FindChunk ("cue ");
    if (data_p) {
        data_p += 32;
        info.loopstart = GetLittleLong ();
        // Con_Printf("loopstart=%d\n", sfx->loopstart);

        // if the next chunk is a LIST chunk, look for a cue length marker
        FindNextChunk ("LIST");
        if (data_p) {
            if (!strncmp ((char *) data_p + 28, "mark", 4)) {   // lxndr: added cast // this is not a proper parse, but it works with cooledit...
                data_p += 24;
                i = GetLittleLong ();  // samples in loop
                info.samples = info.loopstart + i;
                // Con_Printf("looped length: %i\n", i);
            }
        }
    } else
        info.loopstart = -1;

    // find data chunk
    FindChunk ("data");
    if (!data_p) {
        Con_Printf ("Missing data chunk\n");
        return info;
    }

    data_p += 4;
    samples = GetLittleLong () / info.width;

    if (info.samples) {
        if (samples < info.samples)
            Sys_Error ("Sound %s has a bad loop length", name);
    } else
        info.samples = samples;

    info.dataofs = data_p - wav;

    return info;
}
