#include "quakedef.h"

/*

============================================================================

Physics functions (common)
*/

#if	!id386

/*
==================
SV_HullPointContents

==================
*/
static int Q1_HullPointContents (hull_t *hull, int num, vec3_t p)
{
	float		d;
	dclipnode_t	*node;
	mplane_t	*plane;

	while (num >= 0)
	{
		if (num < hull->firstclipnode || num > hull->lastclipnode)
			Sys_Error ("SV_HullPointContents: bad node number");
	
		node = hull->clipnodes + num;
		plane = hull->planes + node->planenum;
		
		if (plane->type < 3)
			d = p[plane->type] - plane->dist;
		else
			d = DotProduct (plane->normal, p) - plane->dist;
		if (d < 0)
			num = node->children[1];
		else
			num = node->children[0];
	}
	
	return num;
}
#else
int VARGS Q1_HullPointContents (hull_t *hull, int num, vec3_t p);
#endif	// !id386



#define	DIST_EPSILON	(0.03125)
qboolean Q1BSP_RecursiveHullCheck (hull_t *hull, int num, float p1f, float p2f, vec3_t p1, vec3_t p2, trace_t *trace)
{
	dclipnode_t	*node;
	mplane_t	*plane;
	float		t1, t2;
	float		frac;
	int			i;
	vec3_t		mid;
	int			side;
	float		midf;

// check for empty
	if (num < 0)
	{
		if (num != Q1CONTENTS_SOLID)
		{
			trace->allsolid = false;
			if (num == Q1CONTENTS_EMPTY)
				trace->inopen = true;
			else
				trace->inwater = true;
		}
		else
			trace->startsolid = true;
		return true;		// empty
	}

	if (num < hull->firstclipnode || num > hull->lastclipnode)
		Sys_Error ("Q1BSP_RecursiveHullCheck: bad node number");

//
// find the point distances
//
	node = hull->clipnodes + num;
	plane = hull->planes + node->planenum;

	if (plane->type < 3)
	{
		t1 = p1[plane->type] - plane->dist;
		t2 = p2[plane->type] - plane->dist;
	}
	else
	{
		t1 = DotProduct (plane->normal, p1) - plane->dist;
		t2 = DotProduct (plane->normal, p2) - plane->dist;
	}
	
#if 1
	if (t1 >= 0 && t2 >= 0)
		return Q1BSP_RecursiveHullCheck (hull, node->children[0], p1f, p2f, p1, p2, trace);
	if (t1 < 0 && t2 < 0)
		return Q1BSP_RecursiveHullCheck (hull, node->children[1], p1f, p2f, p1, p2, trace);
#else
	if ( (t1 >= DIST_EPSILON && t2 >= DIST_EPSILON) || (t2 > t1 && t1 >= 0) )
		return Q1BSP_RecursiveHullCheck (hull, node->children[0], p1f, p2f, p1, p2, trace);
	if ( (t1 <= -DIST_EPSILON && t2 <= -DIST_EPSILON) || (t2 < t1 && t1 <= 0) )
		return Q1BSP_RecursiveHullCheck (hull, node->children[1], p1f, p2f, p1, p2, trace);
#endif

// put the crosspoint DIST_EPSILON pixels on the near side
	if (t1 < 0)
		frac = (t1 + DIST_EPSILON)/(t1-t2);
	else
		frac = (t1 - DIST_EPSILON)/(t1-t2);
	if (frac < 0)
		frac = 0;
	if (frac > 1)
		frac = 1;

	midf = p1f + (p2f - p1f)*frac;
	for (i=0 ; i<3 ; i++)
		mid[i] = p1[i] + frac*(p2[i] - p1[i]);

	side = (t1 < 0);

// move up to the node
	if (!Q1BSP_RecursiveHullCheck (hull, node->children[side], p1f, midf, p1, mid, trace) )
		return false;

#ifdef PARANOID
	if (Q1BSP_RecursiveHullCheck (sv_hullmodel, mid, node->children[side])
	== Q1CONTENTS_SOLID)
	{
		Con_Printf ("mid PointInHullSolid\n");
		return false;
	}
#endif
	
	if (Q1_HullPointContents (hull, node->children[side^1], mid)
	!= Q1CONTENTS_SOLID)
// go past the node
		return Q1BSP_RecursiveHullCheck (hull, node->children[side^1], midf, p2f, mid, p2, trace);
	
	if (trace->allsolid)
		return false;		// never got out of the solid area
		
//==================
// the other side of the node is solid, this is the impact point
//==================
	if (!side)
	{
		VectorCopy (plane->normal, trace->plane.normal);
		trace->plane.dist = plane->dist;
	}
	else
	{
		VectorSubtract (vec3_origin, plane->normal, trace->plane.normal);
		trace->plane.dist = -plane->dist;
	}

	while (Q1_HullPointContents (hull, hull->firstclipnode, mid)
	== Q1CONTENTS_SOLID)
	{ // shouldn't really happen, but does occasionally
		frac -= 0.1;
		if (frac < 0)
		{
			trace->fraction = midf;
			VectorCopy (mid, trace->endpos);
			Con_DPrintf ("backup past 0\n");
			return false;
		}
		midf = p1f + (p2f - p1f)*frac;
		for (i=0 ; i<3 ; i++)
			mid[i] = p1[i] + frac*(p2[i] - p1[i]);
	}

	trace->fraction = midf;
	VectorCopy (mid, trace->endpos);

	return false;
}

int Q1BSP_HullPointContents(hull_t *hull, vec3_t p)
{
	switch(Q1_HullPointContents(hull, hull->firstclipnode, p))
	{
	case Q1CONTENTS_EMPTY:
		return FTECONTENTS_EMPTY;
	case Q1CONTENTS_SOLID:
		return FTECONTENTS_SOLID;
	case Q1CONTENTS_WATER:
		return FTECONTENTS_WATER;
	case Q1CONTENTS_SLIME:
		return FTECONTENTS_SLIME;
	case Q1CONTENTS_LAVA:
		return FTECONTENTS_LAVA;
	case Q1CONTENTS_SKY:
		return FTECONTENTS_SKY;
	default:
		Sys_Error("Q1_PointContents: Unknown contents type");
		return FTECONTENTS_SOLID;
	}
}

void Q1BSP_SetHullFuncs(hull_t *hull)
{
	hull->funcs.RecursiveHullCheck = Q1BSP_RecursiveHullCheck;
	hull->funcs.HullPointContents = Q1BSP_HullPointContents;
}

/*
Physics functions (common)

============================================================================

Rendering functions (Client only)
*/
#ifndef SERVERONLY

extern int	r_dlightframecount;

//goes through the nodes marking the surfaces near the dynamic light as lit.
void Q1BSP_MarkLights (dlight_t *light, int bit, mnode_t *node)
{
	mplane_t	*splitplane;
	float		dist;
	msurface_t	*surf;
	int			i;
	
	if (node->contents < 0)
		return;	

	splitplane = node->plane;
	dist = DotProduct (light->origin, splitplane->normal) - splitplane->dist;
	
	if (dist > light->radius)
	{
		Q1BSP_MarkLights (light, bit, node->children[0]);
		return;
	}
	if (dist < -light->radius)
	{
		Q1BSP_MarkLights (light, bit, node->children[1]);
		return;
	}
		
// mark the polygons
	surf = cl.worldmodel->surfaces + node->firstsurface;
	for (i=0 ; i<node->numsurfaces ; i++, surf++)
	{
		if (surf->dlightframe != r_dlightframecount)
		{
			surf->dlightbits = 0;
			surf->dlightframe = r_dlightframecount;
		}
		surf->dlightbits |= bit;
	}

	Q1BSP_MarkLights (light, bit, node->children[0]);
	Q1BSP_MarkLights (light, bit, node->children[1]);
}

#endif
/*
Rendering functions (Client only)

==============================================================================

Server only functions
*/
#ifndef CLIENTONLY

extern int		fatbytes;
extern qbyte	fatpvs[(MAX_MAP_LEAFS+1)/4];

//does the recursive work of Q1BSP_FatPVS
void SV_Q1BSP_AddToFatPVS (vec3_t org, mnode_t *node)
{
	int		i;
	qbyte	*pvs;
	mplane_t	*plane;
	float	d;

	while (1)
	{
	// if this is a leaf, accumulate the pvs bits
		if (node->contents < 0)
		{
			if (node->contents != Q1CONTENTS_SOLID)
			{
				pvs = Mod_Q1LeafPVS ( (mleaf_t *)node, sv.worldmodel, NULL);
				for (i=0 ; i<fatbytes ; i++)
					fatpvs[i] |= pvs[i];
			}
			return;
		}
	
		plane = node->plane;
		d = DotProduct (org, plane->normal) - plane->dist;
		if (d > 8)
			node = node->children[0];
		else if (d < -8)
			node = node->children[1];
		else
		{	// go down both
			SV_Q1BSP_AddToFatPVS (org, node->children[0]);
			node = node->children[1];
		}
	}
}

/*
=============
Q1BSP_FatPVS

Calculates a PVS that is the inclusive or of all leafs within 8 pixels of the
given point.
=============
*/
void Q1BSP_FatPVS (vec3_t org, qboolean add)
{
	fatbytes = (sv.worldmodel->numleafs+31)>>3;
	if (!add)
		Q_memset (fatpvs, 0, fatbytes);
	SV_Q1BSP_AddToFatPVS (org, sv.worldmodel->nodes);
}

qboolean Q1BSP_EdictInFatPVS(edict_t *ent)
{
	int i;
	for (i=0 ; i < ent->num_leafs ; i++)
		if (fatpvs[ent->leafnums[i] >> 3] & (1 << (ent->leafnums[i]&7) ))
			return true;	//we might be able to see this one.
		
	return false;	//none of this ents leafs were visible, so neither is the ent.
}

/*
===============
SV_FindTouchedLeafs

Links the edict to the right leafs so we can get it's potential visability.
===============
*/
void Q1BSP_RFindTouchedLeafs (edict_t *ent, mnode_t *node)
{
	mplane_t	*splitplane;
	mleaf_t		*leaf;
	int			sides;
	int			leafnum;

	if (node->contents == Q1CONTENTS_SOLID)
		return;
	
// add an efrag if the node is a leaf

	if ( node->contents < 0)
	{
		if (ent->num_leafs == MAX_ENT_LEAFS)
			return;

		leaf = (mleaf_t *)node;
		leafnum = leaf - sv.worldmodel->leafs - 1;

		ent->leafnums[ent->num_leafs] = leafnum;
		ent->num_leafs++;			
		return;
	}
	
// NODE_MIXED

	splitplane = node->plane;
	sides = BOX_ON_PLANE_SIDE(ent->v->absmin, ent->v->absmax, splitplane);
	
// recurse down the contacted sides
	if (sides & 1)
		Q1BSP_RFindTouchedLeafs (ent, node->children[0]);
		
	if (sides & 2)
		Q1BSP_RFindTouchedLeafs (ent, node->children[1]);
}
void Q1BSP_FindTouchedLeafs(edict_t *ent)
{
	ent->num_leafs = 0;
	if (ent->v->modelindex)
		Q1BSP_RFindTouchedLeafs (ent, sv.worldmodel->nodes);
}

#endif
/*
Server only functions

==============================================================================

*/