//=======================================================================
//			Copyright XashXT Group 2007 ©
//			cm_portals.c - server visibility
//=======================================================================

#include "cm_local.h"

static byte fatpvs[MAX_MAP_LEAFS/8];
static byte fatphs[MAX_MAP_LEAFS/8];

/*
===================
CM_DecompressVis
===================
*/
static byte *CM_DecompressVis( const byte *in )
{
	static byte	decompressed[MAX_MAP_LEAFS/8];
	int		c, row;
	byte		*out;

	if( !worldmodel )
	{
		Host_Error( "CM_DecompressVis: no worldmodel\n" );
		return NULL;
	}

	row = (worldmodel->numleafs + 7)>>3;	
	out = decompressed;

	if( !in )
	{	
		// no vis info, so make all visible
		while( row )
		{
			*out++ = 0xff;
			row--;
		}
		return decompressed;		
	}

	do
	{
		if( *in )
		{
			*out++ = *in++;
			continue;
		}
	
		c = in[1];
		in += 2;

		while( c )
		{
			*out++ = 0;
			c--;
		}
	} while( out - decompressed < row );

	return decompressed;
}

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

PVS / PHS

===============================================================================
*/
/*
=================
CM_CalcPHS
=================
*/
void CM_CalcPHS( void )
{
	int	i, j, k, l, index, num;
	int	rowbytes, rowwords;
	int	bitbyte;
	uint	*dest, *src;
	byte	*scan;
	int	hcount, vcount;
	uint	timestart;

	if( !worldmodel ) return;

	if( !worldmodel->visdata )
	{
		cm.pvs = cm.phs = NULL;
		return;
	}

	MsgDev( D_NOTE, "Building PHS...\n" );
	timestart = Sys_Milliseconds();

	num = worldmodel->numleafs;
	rowwords = (num + 31)>>5;
	rowbytes = rowwords * 4;

	cm.pvs = Mem_Alloc( worldmodel->mempool, rowbytes * num );
	scan = cm.pvs;
	vcount = 0;

	// uncompress pvs first
	for( i = 0; i < num; i++, scan += rowbytes )
	{
		byte	*visblock = worldmodel->leafs[i].compressed_vis;

		Mem_Copy( scan, CM_DecompressVis( visblock ), rowbytes );

		if( i == 0 ) continue;

		for( j = 0; j < num; j++ )
		{
			if( scan[j>>3] & (1<<( j & 7 )))
			{
				vcount++;
			}
		}
	}

	MsgDev( D_INFO, "Average clusters visible: %i (build at %g secs)\n", vcount / num, (Sys_Milliseconds() - timestart) * 0.001f );
	timestart = Sys_Milliseconds();

	cm.phs = Mem_Alloc( worldmodel->mempool, rowbytes * num );
	scan = cm.pvs;
	hcount = 0;

	dest = (uint *)cm.phs;

	for( i = 0; i < num; i++, dest += rowwords, scan += rowbytes )
	{
		Mem_Copy( dest, scan, rowbytes );

		for( j = 0; j < rowbytes; j++ )
		{
			bitbyte = scan[j];
			if( !bitbyte ) continue;

			for( k = 0; k < 8; k++ )
			{
				if(!( bitbyte & ( 1<<k )))
					continue;
				// or this pvs row into the phs
				// +1 because pvs is 1 based
				index = ((j<<3) + k + 1);
				if( index >= num ) continue;

				src = (uint *)cm.pvs + index * rowwords;
				for( l = 0; l < rowwords; l++ )
					dest[l] |= src[l];
			}
		}

		if( i == 0 ) continue;

		for( j = 0; j < num; j++ )
		{
			if(((byte *)dest)[j>>3] & (1<<( j & 7 )))
			{
				hcount++;
			}
		}
	}

	MsgDev( D_INFO, "Average clusters hearable: %i (build at %g secs)\n", hcount / num, (Sys_Milliseconds() - timestart) * 0.001f );
	MsgDev( D_INFO, "Total clusters: %i\n", num );
}

/*
=================
CM_LeafPVS
=================
*/
byte *CM_LeafPVS( int leafnum )
{
	if( !worldmodel || leafnum < 0 || leafnum >= worldmodel->numleafs || !cm.pvs )
		return cm.nullrow;
	return cm.pvs + leafnum * sizeof( int ) * ((worldmodel->numleafs + 31)>>5);
}

/*
=================
CM_LeafPHS
=================
*/
byte *CM_LeafPHS( int leafnum )
{
	if( !worldmodel || leafnum < 0 || leafnum >= worldmodel->numleafs || !cm.phs )
		return cm.nullrow;
	return cm.phs + leafnum * sizeof( int ) * ((worldmodel->numleafs + 31)>>5);
}

/*
============
CM_FatPVS

The client will interpolate the view position,
so we can't use a single PVS point
===========
*/
byte *CM_FatPVS( const vec3_t org, bool portal )
{
	short	leafs[128];
	int	i, j, count;
	int	longs;
	byte	*src;
	vec3_t	mins, maxs;
	int	snap = portal ? 1 : 8;

	for( i = 0; i < 3; i++ )
	{
		mins[i] = org[i] - snap;
		maxs[i] = org[i] + snap;
	}

	count = CM_BoxLeafnums( mins, maxs, leafs, 128, NULL );
	if( count < 1 ) Host_Error( "CM_FatPVS: invalid leafnum count\n" );
	longs = (worldmodel->numleafs + 31)>>5;

	if( !portal ) Mem_Copy( fatpvs, CM_LeafPVS( leafs[0] ), longs << 2 );

	// or in all the other leaf bits
	for( i = portal ? 0 : 1; i < count; i++ )
	{
		for( j = 0; j < i; j++ )
		{
			if( leafs[i] == leafs[j] )
				break;
		}

		if( j != i ) continue;	// already have the leaf we want
		src = CM_LeafPVS( leafs[i] );

		for( j = 0; j < longs; j++ )
			((long *)fatpvs)[j] |= ((long *)src)[j];
	}
	return fatpvs;
}

/*
============
CM_FatPHS

The client will interpolate the hear position,
so we can't use a single PHS point
===========
*/
byte *CM_FatPHS( const vec3_t org, bool portal )
{
	int	longs, leafnum;

	longs = (worldmodel->numleafs + 31)>>5;
	leafnum = CM_PointLeafnum( org );

	if( !portal )
	{
		Mem_Copy( fatphs, CM_LeafPHS( leafnum ), longs << 2 );
	}
	else
	{
		byte	*src;
		int	i;

		// or in all the other leaf bits
		src = CM_LeafPHS( leafnum );

		for( i = 0; i < longs; i++ )
			((int *)fatphs)[i] |= ((int *)src)[i];
	}

	return fatphs;
}