/*
 * r_efrag.c -- entity fragments
 * $Id: r_efrag.c,v 1.9 2008-04-22 13:06:07 sezero Exp $
 *
 * Copyright (C) 1996-1997  Id Software, Inc.
 * Copyright (C) 1997-1998  Raven Software Corp.
 *
 * This program 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.
 *
 * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "quakedef.h"
#include "r_local.h"

mnode_t		*r_pefragtopnode;


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

					ENTITY FRAGMENT FUNCTIONS

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

static efrag_t		**lastlink;
static entity_t		*r_addent;
vec3_t			r_emins, r_emaxs;


/*
================
R_RemoveEfrags

Call when removing an object from the world or moving it to another position
================
*/
void R_RemoveEfrags (entity_t *ent)
{
	efrag_t		*ef, *old, *walk, **prev;

	ef = ent->efrag;

	while (ef)
	{
		prev = &ef->leaf->efrags;
		while (1)
		{
			walk = *prev;
			if (!walk)
				break;
			if (walk == ef)
			{	// remove this fragment
				*prev = ef->leafnext;
				break;
			}
			else
				prev = &walk->leafnext;
		}

		old = ef;
		ef = ef->entnext;

	// put it on the free list
		old->entnext = cl.free_efrags;
		cl.free_efrags = old;
	}

	ent->efrag = NULL;
}

/*
===================
R_SplitEntityOnNode
===================
*/
static void R_SplitEntityOnNode (mnode_t *node)
{
	efrag_t		*ef;
	mplane_t	*splitplane;
	mleaf_t		*leaf;
	int			sides;

	if (node->contents == CONTENTS_SOLID)
	{
		return;
	}

// add an efrag if the node is a leaf

	if ( node->contents < 0)
	{
		if (!r_pefragtopnode)
			r_pefragtopnode = node;

		leaf = (mleaf_t *)node;

// grab an efrag off the free list
		ef = cl.free_efrags;
		if (!ef)
		{
			Con_Printf ("Too many efrags!\n");
			return;		// no free fragments...
		}
		cl.free_efrags = cl.free_efrags->entnext;

		ef->entity = r_addent;

// add the entity link
		*lastlink = ef;
		lastlink = &ef->entnext;
		ef->entnext = NULL;

// set the leaf links
		ef->leaf = leaf;
		ef->leafnext = leaf->efrags;
		leaf->efrags = ef;

		return;
	}

// NODE_MIXED

	splitplane = node->plane;
	sides = BOX_ON_PLANE_SIDE(r_emins, r_emaxs, splitplane);

	if (sides == 3)
	{
	// split on this plane
	// if this is the first splitter of this bmodel, remember it
		if (!r_pefragtopnode)
			r_pefragtopnode = node;
	}

// recurse down the contacted sides
	if (sides & 1)
		R_SplitEntityOnNode (node->children[0]);

	if (sides & 2)
		R_SplitEntityOnNode (node->children[1]);
}


/*
===================
R_SplitEntityOnNode2
===================
*/
void R_SplitEntityOnNode2 (mnode_t *node)
{
	mplane_t	*splitplane;
	int			sides;

	if (node->visframe != r_visframecount)
		return;

	if (node->contents < 0)
	{
		if (node->contents != CONTENTS_SOLID)
			r_pefragtopnode = node;	// we've reached a non-solid leaf, so it's
						// visible and not BSP clipped
		return;
	}

	splitplane = node->plane;
	sides = BOX_ON_PLANE_SIDE(r_emins, r_emaxs, splitplane);

	if (sides == 3)
	{
	// remember first splitter
		r_pefragtopnode = node;
		return;
	}

// not split yet; recurse down the contacted side
	if (sides & 1)
		R_SplitEntityOnNode2 (node->children[0]);
	else
		R_SplitEntityOnNode2 (node->children[1]);
}


/*
===========
R_AddEfrags
===========
*/
void R_AddEfrags (entity_t *ent)
{
	qmodel_t	*entmodel;
	int			i;

	if (!ent->model)
		return;

	if (ent == &r_worldentity)
		return;		// never add the world

	r_addent = ent;

	lastlink = &ent->efrag;
	r_pefragtopnode = NULL;

	entmodel = ent->model;

	for (i = 0; i < 3; i++)
	{
		r_emins[i] = ent->origin[i] + entmodel->mins[i];
		r_emaxs[i] = ent->origin[i] + entmodel->maxs[i];
	}

	R_SplitEntityOnNode (cl.worldmodel->nodes);

	ent->topnode = r_pefragtopnode;
}


/*
================
R_StoreEfrags

// FIXME: a lot of this goes away with edge-based
================
*/
void R_StoreEfrags (efrag_t **ppefrag)
{
	entity_t	*pent;
	qmodel_t	*clmodel;
	efrag_t		*pefrag;

	while ((pefrag = *ppefrag) != NULL)
	{
		pent = pefrag->entity;
		clmodel = pent->model;

		switch (clmodel->type)
		{
		case mod_alias:
		case mod_brush:
		case mod_sprite:
			pent = pefrag->entity;

			if ((pent->visframe != r_framecount) &&
				(cl_numvisedicts < MAX_VISEDICTS))
			{

#if defined (H2W)
				cl_visedicts[cl_numvisedicts++] = *pent;
#else
				cl_visedicts[cl_numvisedicts++] = pent;
#endif

			// mark that we've recorded this entity for this frame
				pent->visframe = r_framecount;
			}

			ppefrag = &pefrag->leafnext;
			break;

		default:
			Sys_Error ("%s: Bad entity type %d", __thisfunc__, clmodel->type);
		}
	}
}

