#include "cmdlib.h"
#include "mathlib.h"
#include "polylib.h"
#include "qfiles.h"
#include <assert.h>


extern int numthreads;

// counters are only bumped when running single threaded,
// because they are an awefull coherence problem
int c_active_windings;
int c_peak_windings;
int c_winding_allocs;
int c_winding_points;

#define BOGUS_RANGE ( 2 * MAX_MAP_BOUNDS )

void pw( winding_t *w )
{
	int i;
	for( i = 0; i < w->numpoints; i++ )
		printf( "(%5.1f, %5.1f, %5.1f)\n", w->p[i][0], w->p[i][1], w->p[i][2] );
}

/*
=============
AllocWinding
=============
*/
winding_t *AllocWinding( int points )
{
	winding_t *w;
	int       s;

	if( points > MAX_POINTS_ON_WINDING )
		Error( "Exceeded MAX_POINTS_ON_WINDING" );


	if( numthreads == 1 )
	{
		c_winding_allocs++;
		c_winding_points += points;
		c_active_windings++;
		if( c_active_windings > c_peak_windings )
			c_peak_windings = c_active_windings;
	}

	s = (int)((winding_t *)0 )->p[points];
	w = malloc( s );
	memset( w, 0, s );
	return w;
}

void FreeWinding( winding_t *w )
{
	if( *(unsigned *)w == 0xdeaddead )
		Error( "FreeWinding: freed a freed winding" );
	*(unsigned *)w = 0xdeaddead;

	if( numthreads == 1 )
		c_active_windings--;
	free( w );
}

/*
============
RemoveColinearPoints
============
*/
int c_removed;

void RemoveColinearPoints( winding_t *w )
{
	int    i, j, k;
	vec3_t v1, v2;
	int    nump;
	vec3_t p[MAX_POINTS_ON_WINDING];

	nump = 0;
	for( i = 0; i < w->numpoints; i++ )
	{
		j = ( i + 1 ) % w->numpoints;
		k = ( i + w->numpoints - 1 ) % w->numpoints;
		VectorSubtract( w->p[j], w->p[i], v1 );
		VectorSubtract( w->p[i], w->p[k], v2 );
		VectorNormalize( v1, v1 );
		VectorNormalize( v2, v2 );
		if( DotProduct( v1, v2 ) < 0.999 )
		{
			VectorCopy( w->p[i], p[nump] );
			nump++;
		}
	}

	if( nump == w->numpoints )
		return;

	if( numthreads == 1 )
		c_removed += w->numpoints - nump;
	w->numpoints = nump;
	memcpy( w->p, p, nump * sizeof( p[0] ));
}

/*
============
WindingPlane
============
*/
void WindingPlane( winding_t *w, vec3_t normal, vec_t *dist )
{
	vec3_t v1, v2;

	VectorSubtract( w->p[1], w->p[0], v1 );
	VectorSubtract( w->p[2], w->p[0], v2 );
	CrossProduct( v2, v1, normal );
	VectorNormalize( normal, normal );
	*dist = DotProduct( w->p[0], normal );

}

/*
=============
WindingArea
=============
*/
vec_t WindingArea( winding_t *w )
{
	int    i;
	vec3_t d1, d2, cross;
	vec_t  total;

	total = 0;
	for( i = 2; i < w->numpoints; i++ )
	{
		VectorSubtract( w->p[i - 1], w->p[0], d1 );
		VectorSubtract( w->p[i], w->p[0], d2 );
		CrossProduct( d1, d2, cross );
		total += 0.5 * VectorLength( cross );
	}
	return total;
}

void WindingBounds( winding_t *w, vec3_t mins, vec3_t maxs )
{
	vec_t v;
	int   i, j;

	mins[0] = mins[1] = mins[2] = 99999;
	maxs[0] = maxs[1] = maxs[2] = -99999;

	for( i = 0; i < w->numpoints; i++ )
	{
		for( j = 0; j < 3; j++ )
		{
			v = w->p[i][j];
			if( v < mins[j] )
				mins[j] = v;
			if( v > maxs[j] )
				maxs[j] = v;
		}
	}
}

/*
=============
WindingCenter
=============
*/
void WindingCenter( winding_t *w, vec3_t center )
{
	int   i;
	float scale;

	VectorCopy( vec3_origin, center );
	for( i = 0; i < w->numpoints; i++ )
		VectorAdd( w->p[i], center, center );

	scale = 1.0 / w->numpoints;
	VectorScale( center, scale, center );
}

/*
=================
BaseWindingForPlane
=================
*/
winding_t *BaseWindingForPlane( vec3_t normal, vec_t dist )
{
	int       i, x;
	vec_t     max, v;
	vec3_t    org, vright, vup;
	winding_t *w;

// find the major axis

	max = -BOGUS_RANGE;
	x = -1;
	for( i = 0; i < 3; i++ )
	{
		v = fabs( normal[i] );
		if( v > max )
		{
			x = i;
			max = v;
		}
	}
	if( x == -1 )
		Error( "BaseWindingForPlane: no axis found" );

	VectorCopy( vec3_origin, vup );
	switch( x )
	{
	case 0:
	case 1:
		vup[2] = 1;
		break;
	case 2:
		vup[0] = 1;
		break;
	}

	v = DotProduct( vup, normal );
	VectorMA( vup, -v, normal, vup );
	VectorNormalize( vup, vup );

	VectorScale( normal, dist, org );

	CrossProduct( vup, normal, vright );

	VectorScale( vup, ( 2 * MAX_MAP_BOUNDS ), vup );
	VectorScale( vright, ( 2 * MAX_MAP_BOUNDS ), vright );

// project a really big	axis aligned box onto the plane
	w = AllocWinding( 4 );

	VectorSubtract( org, vright, w->p[0] );
	VectorAdd( w->p[0], vup, w->p[0] );

	VectorAdd( org, vright, w->p[1] );
	VectorAdd( w->p[1], vup, w->p[1] );

	VectorAdd( org, vright, w->p[2] );
	VectorSubtract( w->p[2], vup, w->p[2] );

	VectorSubtract( org, vright, w->p[3] );
	VectorSubtract( w->p[3], vup, w->p[3] );

	w->numpoints = 4;

	return w;
}

/*
==================
CopyWindingInPlace
==================
*/
void CopyWindingInPlace( winding_t *out, winding_t *in )
{
	int size;

	size = (int)((winding_t *)0 )->p[in->numpoints];
	memcpy( out, in, size );
}

/*
==================
CopyWinding
==================
*/
winding_t *CopyWinding( winding_t *w )
{
	winding_t *c;

	c = AllocWinding( w->numpoints );
	CopyWindingInPlace( c, w );
	return c;
}

/*
==================
ReverseWinding
==================
*/
winding_t *ReverseWinding( winding_t *w )
{
	int       i;
	winding_t *c;

	c = AllocWinding( w->numpoints );
	for( i = 0; i < w->numpoints; i++ )
	{
		VectorCopy( w->p[w->numpoints - 1 - i], c->p[i] );
	}
	c->numpoints = w->numpoints;
	return c;
}

/*
=============
ClipWindingEpsilon
=============
*/
void ClipWindingEpsilon( winding_t *in, vec3_t normal, vec_t dist, vec_t epsilon, winding_t **front, winding_t **back )
{
	vec_t        dists[MAX_POINTS_ON_WINDING + 4];
	int          sides[MAX_POINTS_ON_WINDING + 4];
	int          counts[3];
	static vec_t dot; // VC 4.2 optimizer bug if not static
	int          i, j;
	vec_t        *p1, *p2;
	vec3_t       mid;
	winding_t    *f, *b;
	int          maxpts;

	assert( in->numpoints <= MAX_POINTS_ON_WINDING );

	counts[0] = counts[1] = counts[2] = 0;

// determine sides for each point
	for( i = 0; i < in->numpoints; i++ )
	{
		dot = DotProduct( in->p[i], normal );
		dot -= dist;
		dists[i] = dot;
		if( dot > epsilon )
			sides[i] = SIDE_FRONT;
		else if( dot < -epsilon )
			sides[i] = SIDE_BACK;
		else
		{
			sides[i] = SIDE_ON;
		}
		counts[sides[i]]++;
	}
	sides[i] = sides[0];
	dists[i] = dists[0];

	*front = *back = NULL;

	if( !counts[0] )
	{
		*back = CopyWinding( in );
		return;
	}
	if( !counts[1] )
	{
		*front = CopyWinding( in );
		return;
	}

	maxpts = in->numpoints + 4; // cant use counts[0]+2 because
	// of fp grouping errors

	*front = f = AllocWinding( maxpts );
	*back = b = AllocWinding( maxpts );

	for( i = 0; i < in->numpoints; i++ )
	{
		p1 = in->p[i];

		if( sides[i] == SIDE_ON )
		{
			VectorCopy( p1, f->p[f->numpoints] );
			f->numpoints++;
			VectorCopy( p1, b->p[b->numpoints] );
			b->numpoints++;
			continue;
		}

		if( sides[i] == SIDE_FRONT )
		{
			VectorCopy( p1, f->p[f->numpoints] );
			f->numpoints++;
		}
		if( sides[i] == SIDE_BACK )
		{
			VectorCopy( p1, b->p[b->numpoints] );
			b->numpoints++;
		}

		if( sides[i + 1] == SIDE_ON || sides[i + 1] == sides[i] )
			continue;

		// generate a split point
		p2 = in->p[( i + 1 ) % in->numpoints];

		dot = dists[i] / ( dists[i] - dists[i + 1] );
		for( j = 0; j < 3; j++ )
		{ // avoid round off error when possible
			if( normal[j] == 1 )
				mid[j] = dist;
			else if( normal[j] == -1 )
				mid[j] = -dist;
			else
				mid[j] = p1[j] + dot * ( p2[j] - p1[j] );
		}

		VectorCopy( mid, f->p[f->numpoints] );
		f->numpoints++;
		VectorCopy( mid, b->p[b->numpoints] );
		b->numpoints++;
	}

	if( f->numpoints > maxpts || b->numpoints > maxpts )
		Error( "ClipWinding: points exceeded estimate" );
	if( f->numpoints > MAX_POINTS_ON_WINDING || b->numpoints > MAX_POINTS_ON_WINDING )
		Error( "ClipWinding: MAX_POINTS_ON_WINDING" );
}

/*
=============
ChopWindingInPlace
=============
*/
void ChopWindingInPlace( winding_t **inout, vec3_t normal, vec_t dist, vec_t epsilon )
{
	winding_t    *in;
	vec_t        dists[MAX_POINTS_ON_WINDING + 4];
	int          sides[MAX_POINTS_ON_WINDING + 4];
	int          counts[3];
	static vec_t dot; // VC 4.2 optimizer bug if not static
	int          i, j;
	vec_t        *p1, *p2;
	vec3_t       mid;
	winding_t    *f;
	int          maxpts;

	in = *inout;
	counts[0] = counts[1] = counts[2] = 0;

// determine sides for each point
	for( i = 0; i < in->numpoints; i++ )
	{
		dot = DotProduct( in->p[i], normal );
		dot -= dist;
		dists[i] = dot;
		if( dot > epsilon )
			sides[i] = SIDE_FRONT;
		else if( dot < -epsilon )
			sides[i] = SIDE_BACK;
		else
		{
			sides[i] = SIDE_ON;
		}
		counts[sides[i]]++;
	}
	sides[i] = sides[0];
	dists[i] = dists[0];

	if( !counts[0] )
	{
		FreeWinding( in );
		*inout = NULL;
		return;
	}
	if( !counts[1] )
		return; // inout stays the same

	maxpts = in->numpoints + 4; // cant use counts[0]+2 because
	// of fp grouping errors

	f = AllocWinding( maxpts );

	for( i = 0; i < in->numpoints; i++ )
	{
		p1 = in->p[i];

		if( sides[i] == SIDE_ON )
		{
			VectorCopy( p1, f->p[f->numpoints] );
			f->numpoints++;
			continue;
		}

		if( sides[i] == SIDE_FRONT )
		{
			VectorCopy( p1, f->p[f->numpoints] );
			f->numpoints++;
		}

		if( sides[i + 1] == SIDE_ON || sides[i + 1] == sides[i] )
			continue;

		// generate a split point
		p2 = in->p[( i + 1 ) % in->numpoints];

		dot = dists[i] / ( dists[i] - dists[i + 1] );
		for( j = 0; j < 3; j++ )
		{ // avoid round off error when possible
			if( normal[j] == 1 )
				mid[j] = dist;
			else if( normal[j] == -1 )
				mid[j] = -dist;
			else
				mid[j] = p1[j] + dot * ( p2[j] - p1[j] );
		}

		VectorCopy( mid, f->p[f->numpoints] );
		f->numpoints++;
	}

	if( f->numpoints > maxpts )
		Error( "ClipWinding: points exceeded estimate" );
	if( f->numpoints > MAX_POINTS_ON_WINDING )
		Error( "ClipWinding: MAX_POINTS_ON_WINDING" );

	FreeWinding( in );
	*inout = f;
}

/*
=================
ChopWinding

Returns the fragment of in that is on the front side
of the cliping plane.  The original is freed.
=================
*/
winding_t *ChopWinding( winding_t *in, vec3_t normal, vec_t dist )
{
	winding_t *f, *b;

	ClipWindingEpsilon( in, normal, dist, ON_EPSILON, &f, &b );
	FreeWinding( in );
	if( b )
		FreeWinding( b );
	return f;
}

/*
=================
CheckWinding

=================
*/
void CheckWinding( winding_t *w )
{
	int    i, j;
	vec_t  *p1, *p2;
	vec_t  d, edgedist;
	vec3_t dir, edgenormal, facenormal;
	vec_t  area;
	vec_t  facedist;

	if( w->numpoints < 3 )
		Error( "CheckWinding: %i points", w->numpoints );

	area = WindingArea( w );
	if( area < 1 )
		Error( "CheckWinding: %f area", area );

	WindingPlane( w, facenormal, &facedist );

	for( i = 0; i < w->numpoints; i++ )
	{
		p1 = w->p[i];

		for( j = 0; j < 3; j++ )
			if( p1[j] > BOGUS_RANGE || p1[j] < -BOGUS_RANGE )
				Error( "CheckFace: BUGUS_RANGE: %f", p1[j] );

		j = i + 1 == w->numpoints ? 0 : i + 1;

		// check the point is on the face plane
		d = DotProduct( p1, facenormal ) - facedist;
		if( d < -ON_EPSILON || d > ON_EPSILON )
			Error( "CheckWinding: point off plane" );

		// check the edge isnt degenerate
		p2 = w->p[j];
		VectorSubtract( p2, p1, dir );

		if( VectorLength( dir ) < ON_EPSILON )
			Error( "CheckWinding: degenerate edge" );

		CrossProduct( facenormal, dir, edgenormal );
		VectorNormalize( edgenormal, edgenormal );
		edgedist = DotProduct( p1, edgenormal );
		edgedist += ON_EPSILON;

		// all other points must be on front side
		for( j = 0; j < w->numpoints; j++ )
		{
			if( j == i )
				continue;
			d = DotProduct( w->p[j], edgenormal );
			if( d > edgedist )
				Error( "CheckWinding: non-convex" );
		}
	}
}

/*
============
WindingOnPlaneSide
============
*/
int WindingOnPlaneSide( winding_t *w, vec3_t normal, vec_t dist )
{
	qboolean front, back;
	int      i;
	vec_t    d;

	front = qfalse;
	back = qfalse;
	for( i = 0; i < w->numpoints; i++ )
	{
		d = DotProduct( w->p[i], normal ) - dist;
		if( d < -ON_EPSILON )
		{
			if( front )
				return SIDE_CROSS;
			back = qtrue;
			continue;
		}
		if( d > ON_EPSILON )
		{
			if( back )
				return SIDE_CROSS;
			front = qtrue;
			continue;
		}
	}

	if( back )
		return SIDE_BACK;
	if( front )
		return SIDE_FRONT;
	return SIDE_ON;
}

/*
=================
AddWindingToConvexHull

Both w and *hull are on the same plane
=================
*/
#define MAX_HULL_POINTS 128
void AddWindingToConvexHull( winding_t *w, winding_t **hull, vec3_t normal )
{
	int      i, j, k;
	float    *p, *copy;
	vec3_t   dir;
	float    d;
	int      numHullPoints, numNew;
	vec3_t   hullPoints[MAX_HULL_POINTS];
	vec3_t   newHullPoints[MAX_HULL_POINTS];
	vec3_t   hullDirs[MAX_HULL_POINTS];
	qboolean hullSide[MAX_HULL_POINTS];
	qboolean outside;

	if( !*hull )
	{
		*hull = CopyWinding( w );
		return;
	}

	numHullPoints = ( *hull )->numpoints;
	memcpy( hullPoints, ( *hull )->p, numHullPoints * sizeof( vec3_t ));

	for( i = 0; i < w->numpoints; i++ )
	{
		p = w->p[i];

		// calculate hull side vectors
		for( j = 0; j < numHullPoints; j++ )
		{
			k = ( j + 1 ) % numHullPoints;

			VectorSubtract( hullPoints[k], hullPoints[j], dir );
			VectorNormalize( dir, dir );
			CrossProduct( normal, dir, hullDirs[j] );
		}

		outside = qfalse;
		for( j = 0; j < numHullPoints; j++ )
		{
			VectorSubtract( p, hullPoints[j], dir );
			d = DotProduct( dir, hullDirs[j] );
			if( d >= ON_EPSILON )
			{
				outside = qtrue;
			}
			if( d >= -ON_EPSILON )
			{
				hullSide[j] = qtrue;
			}
			else
			{
				hullSide[j] = qfalse;
			}
		}

		// if the point is effectively inside, do nothing
		if( !outside )
		{
			continue;
		}

		// find the back side to front side transition
		for( j = 0; j < numHullPoints; j++ )
		{
			if( !hullSide[ j % numHullPoints ] && hullSide[ ( j + 1 ) % numHullPoints ] )
			{
				break;
			}
		}
		if( j == numHullPoints )
		{
			continue;
		}

		// insert the point here
		VectorCopy( p, newHullPoints[0] );
		numNew = 1;

		// copy over all points that aren't double fronts
		j = ( j + 1 ) % numHullPoints;
		for( k = 0; k < numHullPoints; k++ )
		{
			if( hullSide[ ( j + k ) % numHullPoints ] && hullSide[ ( j + k + 1 ) % numHullPoints ] )
			{
				continue;
			}
			copy = hullPoints[ ( j + k + 1 ) % numHullPoints ];
			VectorCopy( copy, newHullPoints[numNew] );
			numNew++;
		}

		numHullPoints = numNew;
		memcpy( hullPoints, newHullPoints, numHullPoints * sizeof( vec3_t ));
	}

	FreeWinding( *hull );
	w = AllocWinding( numHullPoints );
	w->numpoints = numHullPoints;
	*hull = w;
	memcpy( w->p, hullPoints, numHullPoints * sizeof( vec3_t ));
}
