/*
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 (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
    loadedfile_t	*fileinfo;	// 2001-09-12 Returning information about loaded file by Maddes

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

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

    if (developer.value == 1) {
        Con_DPrintf("Loading %s\n",namebuffer);    // Edited
    }
//	Con_Printf ("loading %s\n",namebuffer);

// 2001-09-12 Returning information about loaded file by Maddes  start
    /*
    	data = COM_LoadStackFile(namebuffer, stackbuf, sizeof(stackbuf));

    	if (!data)
    */
    fileinfo = COM_LoadStackFile(namebuffer, stackbuf, sizeof(stackbuf));
    if (!fileinfo)
// 2001-09-12 Returning information about loaded file by Maddes  end
    {
        Con_Printf("Couldn't load %s\n", namebuffer);
        return NULL;
    }
    data = fileinfo->data;	// 2001-09-12 Returning information about loaded file by Maddes

    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 (!Q_strncmp(data_p, name, 4)) {
            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 && !Q_strncmp(data_p+8, "WAVE", 4))) {
        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(data_p + 28, "mark", 4)) {
                // 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;
}

