/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code 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.

Quake III Arena source code 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 Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/

/*****************************************************************************
 * name:		snd_mem.c
 *
 * desc:		sound caching
 *
 * $Archive: /MissionPack/code/client/snd_mem.c $
 *
 *****************************************************************************/

#include "snd_local.h"

#define DEF_COMSOUNDMEGS "8"

/*
===============================================================================

memory management

===============================================================================
*/

static	sndBuffer	*buffer = NULL;
static	sndBuffer	*freelist = NULL;
static	int inUse = 0;
static	int totalInUse = 0;

short *sfxScratchBuffer = NULL;
sfx_t *sfxScratchPointer = NULL;
int	   sfxScratchIndex = 0;

void	SND_free(sndBuffer *v) {
	*(sndBuffer **)v = freelist;
	freelist = (sndBuffer*)v;
	inUse += sizeof(sndBuffer);
}

sndBuffer*	SND_malloc() {
	sndBuffer *v;
redo:
	if (freelist == NULL) {
		S_FreeOldestSound();
		goto redo;
	}

	inUse -= sizeof(sndBuffer);
	totalInUse += sizeof(sndBuffer);

	v = freelist;
	freelist = *(sndBuffer **)freelist;
	v->next = NULL;
	return v;
}

void SND_setup() {
	sndBuffer *p, *q;
	cvar_t	*cv;
	int scs;

	cv = Cvar_Get( "com_soundMegs", DEF_COMSOUNDMEGS, CVAR_LATCH | CVAR_ARCHIVE );

	scs = (cv->integer*1536);

	buffer = malloc(scs*sizeof(sndBuffer) );
	// allocate the stack based hunk allocator
	sfxScratchBuffer = malloc(SND_CHUNK_SIZE * sizeof(short) * 4);	//Hunk_Alloc(SND_CHUNK_SIZE * sizeof(short) * 4);
	sfxScratchPointer = NULL;

	inUse = scs*sizeof(sndBuffer);
	p = buffer;;
	q = p + scs;
	while (--q > p)
		*(sndBuffer **)q = q-1;
	
	*(sndBuffer **)q = NULL;
	freelist = p + scs - 1;

	Com_Printf("Sound memory manager started\n");
}

/*
===============================================================================

WAV loading

===============================================================================
*/

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

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

static 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;
}

static 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;
		}
		data_p -= 8;
		last_chunk = data_p + 8 + ( (iff_chunk_len + 1) & ~1 );
		if (!strncmp((char *)data_p, name, 4))
			return;
	}
}

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

/*
============
GetWavinfo
============
*/
static wavinfo_t GetWavinfo (char *name, byte *wav, int wavlength)
{
	wavinfo_t	info;

	Com_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)))
	{
		Com_Printf("Missing RIFF/WAVE chunks\n");
		return info;
	}

// get "fmt " chunk
	iff_data = data_p + 12;
// DumpChunks ();

	FindChunk("fmt ");
	if (!data_p)
	{
		Com_Printf("Missing fmt chunk\n");
		return info;
	}
	data_p += 8;
	info.format = GetLittleShort();
	info.channels = GetLittleShort();
	info.rate = GetLittleLong();
	data_p += 4+2;
	info.width = GetLittleShort() / 8;

	if (info.format != 1)
	{
		Com_Printf("Microsoft PCM format only\n");
		return info;
	}


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

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

	return info;
}


/*
================
ResampleSfx

resample / decimate to the current source rate
================
*/
static void ResampleSfx( sfx_t *sfx, int inrate, int inwidth, byte *data, qboolean compressed ) {
	int		outcount;
	int		srcsample;
	float	stepscale;
	int		i;
	int		sample, samplefrac, fracstep;
	int			part;
	sndBuffer	*chunk;
	
	stepscale = (float)inrate / dma.speed;	// this is usually 0.5, 1, or 2

	outcount = sfx->soundLength / stepscale;
	sfx->soundLength = outcount;

	samplefrac = 0;
	fracstep = stepscale * 256;
	chunk = sfx->soundData;

	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;
		}
		part  = (i&(SND_CHUNK_SIZE-1));
		if (part == 0) {
			sndBuffer	*newchunk;
			newchunk = SND_malloc();
			if (chunk == NULL) {
				sfx->soundData = newchunk;
			} else {
				chunk->next = newchunk;
			}
			chunk = newchunk;
		}

		chunk->sndChunk[part] = sample;
	}
}

/*
================
ResampleSfx

resample / decimate to the current source rate
================
*/
static int ResampleSfxRaw( short *sfx, int inrate, int inwidth, int samples, byte *data ) {
	int			outcount;
	int			srcsample;
	float		stepscale;
	int			i;
	int			sample, samplefrac, fracstep;
	
	stepscale = (float)inrate / dma.speed;	// this is usually 0.5, 1, or 2

	outcount = samples / stepscale;

	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;
		}
		sfx[i] = sample;
	}
	return outcount;
}


//=============================================================================

/*
==============
S_LoadSound

The filename may be different than sfx->name in the case
of a forced fallback of a player specific sound
==============
*/
qboolean S_LoadSound( sfx_t *sfx )
{
	byte	*data;
	short	*samples;
	wavinfo_t	info;
	int		size;

	// player specific sounds are never directly loaded
	if ( sfx->soundName[0] == '*') {
		return qfalse;
	}

	// load it in
	size = FS_ReadFile( sfx->soundName, (void **)&data );
	if ( !data ) {
		return qfalse;
	}

	info = GetWavinfo( sfx->soundName, data, size );
	if ( info.channels != 1 ) {
		Com_Printf ("%s is a stereo wav file\n", sfx->soundName);
		FS_FreeFile (data);
		return qfalse;
	}

	if ( info.width == 1 ) {
		Com_DPrintf(S_COLOR_YELLOW "WARNING: %s is a 8 bit wav file\n", sfx->soundName);
	}

	if ( info.rate != 22050 ) {
		Com_DPrintf(S_COLOR_YELLOW "WARNING: %s is not a 22kHz wav file\n", sfx->soundName);
	}

	samples = Hunk_AllocateTempMemory(info.samples * sizeof(short) * 2);

	sfx->lastTimeUsed = Com_Milliseconds()+1;

	// each of these compression schemes works just fine
	// but the 16bit quality is much nicer and with a local
	// install assured we can rely upon the sound memory
	// manager to do the right thing for us and page
	// sound in as needed

	if( sfx->soundCompressed == qtrue) {
		sfx->soundCompressionMethod = 1;
		sfx->soundData = NULL;
		sfx->soundLength = ResampleSfxRaw( samples, info.rate, info.width, info.samples, (data + info.dataofs) );
		S_AdpcmEncodeSound(sfx, samples);
#if 0
	} else if (info.samples>(SND_CHUNK_SIZE*16) && info.width >1) {
		sfx->soundCompressionMethod = 3;
		sfx->soundData = NULL;
		sfx->soundLength = ResampleSfxRaw( samples, info.rate, info.width, info.samples, (data + info.dataofs) );
		encodeMuLaw( sfx, samples);
	} else if (info.samples>(SND_CHUNK_SIZE*6400) && info.width >1) {
		sfx->soundCompressionMethod = 2;
		sfx->soundData = NULL;
		sfx->soundLength = ResampleSfxRaw( samples, info.rate, info.width, info.samples, (data + info.dataofs) );
		encodeWavelet( sfx, samples);
#endif
	} else {
		sfx->soundCompressionMethod = 0;
		sfx->soundLength = info.samples;
		sfx->soundData = NULL;
		ResampleSfx( sfx, info.rate, info.width, data + info.dataofs, qfalse );
	}
	
	Hunk_FreeTempMemory(samples);
	FS_FreeFile( data );

	return qtrue;
}

void S_DisplayFreeMemory() {
	Com_Printf("%d bytes free sound buffer memory, %d total used\n", inUse, totalInUse);
}