/*
Copyright (C) 1996-1997 Id Software, Inc.

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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/
// r_efrag.c

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

mnode_t	*r_pefragtopnode;


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

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

					ENTITY FRAGMENT FUNCTIONS

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

efrag_t		**lastlink;

vec3_t		r_emins, r_emaxs;

entity_t	*r_addent;


//Edited added from
// mh - extended efrags - begin
#define EXTRA_EFRAGS   64 //32 Edited

void R_GetMoreEfrags(void)
{
    int i;

    cl.free_efrags = (efrag_t *) Hunk_Alloc(EXTRA_EFRAGS * sizeof(efrag_t));

    for (i = 0; i < EXTRA_EFRAGS - 1; i++) {
        cl.free_efrags[i].entnext = &cl.free_efrags[i + 1];
    }

    cl.free_efrags[i].entnext = NULL;
}
// mh - extended efrags - end


/*
================
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
===================
*/
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) {
            // mh - extended efrags - begin
            R_GetMoreEfrags();
            ef = cl.free_efrags;
            // mh - extended efrags - end
        }
        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)
{
    model_t		*entmodel;
    int			i;

    if (!ent->model) {
        return;
    }

    if (ent == cl_entities) {
        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;
    model_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)) {
                cl_visedicts[cl_numvisedicts++] = pent;

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

            ppefrag = &pefrag->leafnext;
            break;

        default:
            Sys_Error("R_StoreEfrags: Bad entity type %d\n", clmodel->type);
        }
    }
}


