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

Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company. 

This file is part of the Doom 3 GPL Source Code (?Doom 3 Source Code?).  

Doom 3 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 3 of the License, or
(at your option) any later version.

Doom 3 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 Doom 3 Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code.  If not, please request a copy in writing from id Software at the address below.

If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.

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

#include "../../../idlib/precompiled.h"
#pragma hdrstop

#include "dmap.h"

int		c_active_brushes;

int		c_nodes;

// if a brush just barely pokes onto the other side,
// let it slide by without chopping
#define	PLANESIDE_EPSILON	0.001
//0.1




/*
================
CountBrushList
================
*/
int	CountBrushList (uBrush_t *brushes)
{
	int	c;

	c = 0;
	for ( ; brushes ; brushes = brushes->next)
		c++;
	return c;
}


int BrushSizeForSides( int numsides ) {
	int		c;

	// allocate a structure with a variable number of sides at the end
//	c = (int)&(((uBrush_t *)0)->sides[numsides]);	// bounds checker complains about this
	c = sizeof( uBrush_t ) + sizeof( side_t ) * (numsides - 6);

	return c;
}

/*
================
AllocBrush
================
*/
uBrush_t *AllocBrush (int numsides)
{
	uBrush_t	*bb;
	int			c;

	c = BrushSizeForSides( numsides );

	bb = (uBrush_t *)Mem_Alloc(c);
	memset (bb, 0, c);
	c_active_brushes++;
	return bb;
}

/*
================
FreeBrush
================
*/
void FreeBrush (uBrush_t *brushes)
{
	int			i;

	for ( i = 0 ; i < brushes->numsides ; i++ ) {
		if ( brushes->sides[i].winding ) {
			delete brushes->sides[i].winding;
		}
		if ( brushes->sides[i].visibleHull ) {
			delete brushes->sides[i].visibleHull;
		}
	}
	Mem_Free (brushes);
	c_active_brushes--;
}


/*
================
FreeBrushList
================
*/
void FreeBrushList (uBrush_t *brushes)
{
	uBrush_t	*next;

	for ( ; brushes ; brushes = next)
	{
		next = brushes->next;

		FreeBrush (brushes);
	}		
}

/*
==================
CopyBrush

Duplicates the brush, the sides, and the windings
==================
*/
uBrush_t *CopyBrush (uBrush_t *brush)
{
	uBrush_t *newbrush;
	int			size;
	int			i;
	
	size = BrushSizeForSides( brush->numsides );

	newbrush = AllocBrush (brush->numsides);
	memcpy (newbrush, brush, size);

	for (i=0 ; i<brush->numsides ; i++)
	{
		if (brush->sides[i].winding)
			newbrush->sides[i].winding = brush->sides[i].winding->Copy();
	}

	return newbrush;
}


/*
================
DrawBrushList
================
*/
void DrawBrushList (uBrush_t *brush)
{
	int		i;
	side_t	*s;

	GLS_BeginScene ();
	for ( ; brush ; brush=brush->next)
	{
		for (i=0 ; i<brush->numsides ; i++)
		{
			s = &brush->sides[i];
			if (!s->winding)
				continue;
			GLS_Winding (s->winding, 0);
		}
	}
	GLS_EndScene ();
}


/*
=============
PrintBrush
=============
*/
void PrintBrush (uBrush_t *brush)
{
	int		i;

	common->Printf( "brush: %p\n", brush );
	for ( i=0;i<brush->numsides ; i++ ) {
		brush->sides[i].winding->Print();
		common->Printf ("\n");
	}
}

/*
==================
BoundBrush

Sets the mins/maxs based on the windings
returns false if the brush doesn't enclose a valid volume
==================
*/
bool BoundBrush (uBrush_t *brush) {
	int			i, j;
	idWinding	*w;

	brush->bounds.Clear();
	for ( i = 0; i < brush->numsides; i++ ) {
		w = brush->sides[i].winding;
		if (!w)
			continue;
		for ( j = 0; j < w->GetNumPoints(); j++ )
			brush->bounds.AddPoint( (*w)[j].ToVec3() );
	}

	for ( i = 0; i < 3; i++ ) {
		if (brush->bounds[0][i] < MIN_WORLD_COORD || brush->bounds[1][i] > MAX_WORLD_COORD 
			|| brush->bounds[0][i] >= brush->bounds[1][i] ) {
			return false;
		}
	}

	return true;
}

/*
==================
CreateBrushWindings

makes basewindigs for sides and mins / maxs for the brush
returns false if the brush doesn't enclose a valid volume
==================
*/
bool CreateBrushWindings (uBrush_t *brush) {
	int			i, j;
	idWinding	*w;
	idPlane		*plane;
	side_t		*side;

	for ( i = 0; i < brush->numsides; i++ ) {
		side = &brush->sides[i];
		plane = &dmapGlobals.mapPlanes[side->planenum];
		w = new idWinding( *plane );
		for ( j = 0; j < brush->numsides && w; j++ ) {
			if ( i == j ) {
				continue;
			}
			if ( brush->sides[j].planenum == ( brush->sides[i].planenum ^ 1 ) ) {
				continue;		// back side clipaway
			}
			plane = &dmapGlobals.mapPlanes[brush->sides[j].planenum^1];
			w = w->Clip( *plane, 0 );//CLIP_EPSILON);
		}
		if ( side->winding ) {
			delete side->winding;
		}
		side->winding = w;
	}

	return BoundBrush( brush );
}

/*
==================
BrushFromBounds

Creates a new axial brush
==================
*/
uBrush_t	*BrushFromBounds( const idBounds &bounds ) {
	uBrush_t	*b;
	int			i;
	idPlane		plane;

	b = AllocBrush (6);
	b->numsides = 6;
	for (i=0 ; i<3 ; i++) {
		plane[0] = plane[1] = plane[2] = 0;
		plane[i] = 1;
		plane[3] = -bounds[1][i];
		b->sides[i].planenum = FindFloatPlane( plane );

		plane[i] = -1;
		plane[3] = bounds[0][i];
		b->sides[3+i].planenum = FindFloatPlane( plane );
	}

	CreateBrushWindings (b);

	return b;
}

/*
==================
BrushVolume

==================
*/
float BrushVolume (uBrush_t *brush) {
	int			i;
	idWinding	*w;
	idVec3		corner;
	float		d, area, volume;
	idPlane		*plane;

	if (!brush)
		return 0;

	// grab the first valid point as the corner

	w = NULL;
	for ( i = 0; i < brush->numsides; i++ ) {
		w = brush->sides[i].winding;
		if (w)
			break;
	}
	if (!w) {
		return 0;
	}
	VectorCopy ( (*w)[0], corner);

	// make tetrahedrons to all other faces

	volume = 0;
	for ( ; i < brush->numsides; i++ )
	{
		w = brush->sides[i].winding;
		if (!w)
			continue;
		plane = &dmapGlobals.mapPlanes[brush->sides[i].planenum];
		d = -plane->Distance( corner );
		area = w->GetArea();
		volume += d * area;
	}

	volume /= 3;
	return volume;
}


/*
==================
WriteBspBrushMap

FIXME: use new brush format
==================
*/
void WriteBspBrushMap( const char *name, uBrush_t *list ) {
	idFile *	f;
	side_t *	s;
	int			i;
	idWinding *	w;

	common->Printf ("writing %s\n", name);
	f = fileSystem->OpenFileWrite( name );

	if ( !f ) {
		common->Error( "Can't write %s\b", name);
	}

	f->Printf( "{\n\"classname\" \"worldspawn\"\n" );

	for ( ; list ; list=list->next )
	{
		f->Printf( "{\n" );
		for (i=0,s=list->sides ; i<list->numsides ; i++,s++)
		{
			w = new idWinding( dmapGlobals.mapPlanes[s->planenum] );

			f->Printf ("( %i %i %i ) ", (int)(*w)[0][0], (int)(*w)[0][1], (int)(*w)[0][2]);
			f->Printf ("( %i %i %i ) ", (int)(*w)[1][0], (int)(*w)[1][1], (int)(*w)[1][2]);
			f->Printf ("( %i %i %i ) ", (int)(*w)[2][0], (int)(*w)[2][1], (int)(*w)[2][2]);

			f->Printf ("notexture 0 0 0 1 1\n" );
			delete w;
		}
		f->Printf ("}\n");
	}
	f->Printf ("}\n");

	fileSystem->CloseFile(f);

}


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

/*
====================
FilterBrushIntoTree_r

====================
*/
int FilterBrushIntoTree_r( uBrush_t *b, node_t *node ) {
	uBrush_t		*front, *back;
	int				c;

	if ( !b ) {
		return 0;
	}

	// add it to the leaf list
	if ( node->planenum == PLANENUM_LEAF ) {
		b->next = node->brushlist;
		node->brushlist = b;

		// classify the leaf by the structural brush
		if ( b->opaque ) {
			node->opaque = true;
		}

		return 1;
	}

	// split it by the node plane
	SplitBrush ( b, node->planenum, &front, &back );
	FreeBrush( b );

	c = 0;
	c += FilterBrushIntoTree_r( front, node->children[0] );
	c += FilterBrushIntoTree_r( back, node->children[1] );

	return c;
}


/*
=====================
FilterBrushesIntoTree

Mark the leafs as opaque and areaportals and put brush
fragments in each leaf so portal surfaces can be matched
to materials
=====================
*/
void FilterBrushesIntoTree( uEntity_t *e ) {
	primitive_t			*prim;
	uBrush_t			*b, *newb;
	int					r;
	int					c_unique, c_clusters;

	common->Printf( "----- FilterBrushesIntoTree -----\n");

	c_unique = 0;
	c_clusters = 0;
	for ( prim = e->primitives ; prim ; prim = prim->next ) {
		b = prim->brush;
		if ( !b ) {
			continue;
		}
		c_unique++;
		newb = CopyBrush( b );
		r = FilterBrushIntoTree_r( newb, e->tree->headnode );
		c_clusters += r;
	}

	common->Printf( "%5i total brushes\n", c_unique );
	common->Printf( "%5i cluster references\n", c_clusters );
}



/*
================
AllocTree
================
*/
tree_t *AllocTree (void)
{
	tree_t	*tree;

	tree = (tree_t *)Mem_Alloc(sizeof(*tree));
	memset (tree, 0, sizeof(*tree));
	tree->bounds.Clear();

	return tree;
}

/*
================
AllocNode
================
*/
node_t *AllocNode (void)
{
	node_t	*node;

	node = (node_t *)Mem_Alloc(sizeof(*node));
	memset (node, 0, sizeof(*node));

	return node;
}

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

/*
==================
BrushMostlyOnSide

==================
*/
int BrushMostlyOnSide (uBrush_t *brush, idPlane &plane) {
	int			i, j;
	idWinding	*w;
	float		d, max;
	int			side;

	max = 0;
	side = PSIDE_FRONT;
	for ( i = 0; i < brush->numsides; i++ ) {
		w = brush->sides[i].winding;
		if (!w)
			continue;
		for ( j = 0; j < w->GetNumPoints(); j++ )
		{
			d = plane.Distance( (*w)[j].ToVec3() );
			if (d > max)
			{
				max = d;
				side = PSIDE_FRONT;
			}
			if (-d > max)
			{
				max = -d;
				side = PSIDE_BACK;
			}
		}
	}
	return side;
}

/*
================
SplitBrush

Generates two new brushes, leaving the original
unchanged
================
*/
void SplitBrush (uBrush_t *brush, int planenum, uBrush_t **front, uBrush_t **back) {
	uBrush_t	*b[2];
	int			i, j;
	idWinding	*w, *cw[2], *midwinding;
	side_t		*s, *cs;
	float		d, d_front, d_back;

	*front = *back = NULL;
	idPlane &plane = dmapGlobals.mapPlanes[planenum];

	// check all points
	d_front = d_back = 0;
	for ( i = 0; i < brush->numsides; i++ )
	{
		w = brush->sides[i].winding;
		if (!w) {
			continue;
		}
		for ( j = 0; j < w->GetNumPoints(); j++ ) {
			d = plane.Distance( (*w)[j].ToVec3() );
			if (d > 0 && d > d_front)
				d_front = d;
			if (d < 0 && d < d_back)
				d_back = d;
		}
	}
	if (d_front < 0.1) // PLANESIDE_EPSILON)
	{	// only on back
		*back = CopyBrush( brush );
		return;
	}
	if (d_back > -0.1) // PLANESIDE_EPSILON)
	{	// only on front
		*front = CopyBrush( brush );
		return;
	}

	// create a new winding from the split plane

	w = new idWinding( plane );
	for ( i = 0; i < brush->numsides && w; i++ ) {
		idPlane &plane2 = dmapGlobals.mapPlanes[brush->sides[i].planenum ^ 1];
		w = w->Clip( plane2, 0 ); // PLANESIDE_EPSILON);
	}

	if ( !w || w->IsTiny() ) {
		// the brush isn't really split
		int		side;

		side = BrushMostlyOnSide( brush, plane );
		if (side == PSIDE_FRONT)
			*front = CopyBrush (brush);
		if (side == PSIDE_BACK)
			*back = CopyBrush (brush);
		return;
	}

	if ( w->IsHuge() ) {
		common->Printf ("WARNING: huge winding\n");
	}

	midwinding = w;

	// split it for real

	for ( i = 0; i < 2; i++ ) {
		b[i] = AllocBrush (brush->numsides+1);
		memcpy( b[i], brush, sizeof( uBrush_t ) - sizeof( brush->sides ) );
		b[i]->numsides = 0;
		b[i]->next = NULL;
		b[i]->original = brush->original;
	}

	// split all the current windings

	for ( i = 0; i < brush->numsides; i++ ) {
		s = &brush->sides[i];
		w = s->winding;
		if (!w)
			continue;
		w->Split( plane, 0 /*PLANESIDE_EPSILON*/, &cw[0], &cw[1] );
		for ( j = 0; j < 2; j++ ) {
			if ( !cw[j] ) {
				continue;
			}
/*
			if ( cw[j]->IsTiny() )
			{
				delete cw[j];
				continue;
			}
*/
			cs = &b[j]->sides[b[j]->numsides];
			b[j]->numsides++;
			*cs = *s;
			cs->winding = cw[j];
		}
	}


	// see if we have valid polygons on both sides

	for (i=0 ; i<2 ; i++)
	{
		if ( !BoundBrush (b[i]) ) {
			break;
		}

		if ( b[i]->numsides < 3 )
		{
			FreeBrush (b[i]);
			b[i] = NULL;
		}
	}

	if ( !(b[0] && b[1]) )
	{
		if (!b[0] && !b[1])
			common->Printf ("split removed brush\n");
		else
			common->Printf ("split not on both sides\n");
		if (b[0])
		{
			FreeBrush (b[0]);
			*front = CopyBrush (brush);
		}
		if (b[1])
		{
			FreeBrush (b[1]);
			*back = CopyBrush (brush);
		}
		return;
	}

	// add the midwinding to both sides
	for (i=0 ; i<2 ; i++)
	{
		cs = &b[i]->sides[b[i]->numsides];
		b[i]->numsides++;

		cs->planenum = planenum^i^1;
		cs->material = NULL;
		if (i==0)
			cs->winding = midwinding->Copy();
		else
			cs->winding = midwinding;
	}

{
	float	v1;
	int		i;

	for (i=0 ; i<2 ; i++)
	{
		v1 = BrushVolume (b[i]);
		if (v1 < 1.0)
		{
			FreeBrush (b[i]);
			b[i] = NULL;
//			common->Printf ("tiny volume after clip\n");
		}
	}
}

	*front = b[0];
	*back = b[1];
}