sv_world.c

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/*
Copyright (C) 1997-2001 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.
 
*/
// world.c -- world query functions
 
#include "server.h"
#include <inttypes.h>
 
/*
===============================================================================
 
ENTITY AREA CHECKING
 
FIXME: this use of "area" is different from the bsp file use
===============================================================================
*/
 
// (type *)STRUCT_FROM_LINK(link_t *link, type, member)
// ent = STRUCT_FROM_LINK(link,entity_t,order)
// FIXME: remove this mess!
#define STRUCT_FROM_LINK(l,t,m) ((t *)((byte *)l - (intptr_t)&(((t *)0)->m)))
 
#define EDICT_FROM_AREA(l) STRUCT_FROM_LINK(l,edict_t,area)
 
typedef struct areanode_s
{
    int     axis;       // -1 = leaf node
    float   dist;
    struct areanode_s   *children[2];
    link_t  trigger_edicts;
    link_t  solid_edicts;
} areanode_t;
 
#define AREA_DEPTH  4
#define AREA_NODES  32
 
areanode_t  sv_areanodes[AREA_NODES];
int         sv_numareanodes;
 
float   *area_mins, *area_maxs;
edict_t **area_list;
int     area_count, area_maxcount;
int     area_type;
 
int SV_HullForEntity (edict_t *ent);
 
 
// ClearLink is used for new headnodes
void ClearLink (link_t *l)
{
    l->prev = l->next = l;
}
 
void RemoveLink (link_t *l)
{
    l->next->prev = l->prev;
    l->prev->next = l->next;
}
 
void InsertLinkBefore (link_t *l, link_t *before)
{
    l->next = before;
    l->prev = before->prev;
    l->prev->next = l;
    l->next->prev = l;
}
 
/*
===============
SV_CreateAreaNode
 
Builds a uniformly subdivided tree for the given world size
===============
*/
areanode_t *SV_CreateAreaNode (int depth, vec3_t mins, vec3_t maxs)
{
    areanode_t  *anode;
    vec3_t      size;
    vec3_t      mins1, maxs1, mins2, maxs2;
 
    anode = &sv_areanodes[sv_numareanodes];
    sv_numareanodes++;
 
    ClearLink (&anode->trigger_edicts);
    ClearLink (&anode->solid_edicts);
    
    if (depth == AREA_DEPTH)
    {
        anode->axis = -1;
        anode->children[0] = anode->children[1] = NULL;
        return anode;
    }
    
    VectorSubtract (maxs, mins, size);
    if (size[0] > size[1])
        anode->axis = 0;
    else
        anode->axis = 1;
    
    anode->dist = 0.5 * (maxs[anode->axis] + mins[anode->axis]);
    VectorCopy (mins, mins1);   
    VectorCopy (mins, mins2);   
    VectorCopy (maxs, maxs1);   
    VectorCopy (maxs, maxs2);   
    
    maxs1[anode->axis] = mins2[anode->axis] = anode->dist;
    
    anode->children[0] = SV_CreateAreaNode (depth+1, mins2, maxs2);
    anode->children[1] = SV_CreateAreaNode (depth+1, mins1, maxs1);
 
    return anode;
}
 
/*
===============
SV_ClearWorld
 
===============
*/
void SV_ClearWorld (void)
{
    memset (sv_areanodes, 0, sizeof(sv_areanodes));
    sv_numareanodes = 0;
    SV_CreateAreaNode (0, sv.models[1]->mins, sv.models[1]->maxs);
}
 
 
/*
===============
SV_UnlinkEdict
 
===============
*/
void SV_UnlinkEdict (edict_t *ent)
{
    if (!ent->area.prev)
        return;     // not linked in anywhere
    RemoveLink (&ent->area);
    ent->area.prev = ent->area.next = NULL;
}
 
 
/*
===============
SV_LinkEdict
 
===============
*/
#define MAX_TOTAL_ENT_LEAFS     128
void SV_LinkEdict (edict_t *ent)
{
    areanode_t  *node;
    int         leafs[MAX_TOTAL_ENT_LEAFS];
    int         clusters[MAX_TOTAL_ENT_LEAFS];
    int         num_leafs;
    int         i, j, k;
    int         area;
    int         topnode;
 
    if (ent->area.prev)
        SV_UnlinkEdict (ent);   // unlink from old position
        
    if (ent == ge->edicts)
        return;     // don't add the world
 
    if (!ent->inuse)
        return;
 
    // set the size
    VectorSubtract (ent->maxs, ent->mins, ent->size);
    
    // encode the size into the entity_state for client prediction
    if (ent->solid == SOLID_BBOX && !(ent->svflags & SVF_DEADMONSTER))
    {   // assume that x/y are equal and symetric
        i = ent->maxs[0]/8;
        if (i<1)
            i = 1;
        if (i>31)
            i = 31;
 
        // z is not symetric
        j = (-ent->mins[2])/8;
        if (j<1)
            j = 1;
        if (j>31)
            j = 31;
 
        // and z maxs can be negative...
        k = (ent->maxs[2]+32)/8;
        if (k<1)
            k = 1;
        if (k>63)
            k = 63;
 
        ent->s.solid = (k<<10) | (j<<5) | i;
    }
    else if (ent->solid == SOLID_BSP)
    {
        ent->s.solid = 31;      // a solid_bbox will never create this value
    }
    else
        ent->s.solid = 0;
 
    // set the abs box
    if (ent->solid == SOLID_BSP && 
    (ent->s.angles[0] || ent->s.angles[1] || ent->s.angles[2]) )
    {   // expand for rotation
        float       max, v;
        int         i;
 
        max = 0;
        for (i=0 ; i<3 ; i++)
        {
            v =fabs( ent->mins[i]);
            if (v > max)
                max = v;
            v =fabs( ent->maxs[i]);
            if (v > max)
                max = v;
        }
        for (i=0 ; i<3 ; i++)
        {
            ent->absmin[i] = ent->s.origin[i] - max;
            ent->absmax[i] = ent->s.origin[i] + max;
        }
    }
    else
    {   // normal
        VectorAdd (ent->s.origin, ent->mins, ent->absmin);  
        VectorAdd (ent->s.origin, ent->maxs, ent->absmax);
    }
 
    // because movement is clipped an epsilon away from an actual edge,
    // we must fully check even when bounding boxes don't quite touch
    ent->absmin[0] -= 1;
    ent->absmin[1] -= 1;
    ent->absmin[2] -= 1;
    ent->absmax[0] += 1;
    ent->absmax[1] += 1;
    ent->absmax[2] += 1;
 
// link to PVS leafs
    ent->num_clusters = 0;
    ent->areanum = 0;
    ent->areanum2 = 0;
 
    //get all leafs, including solids
    num_leafs = CM_BoxLeafnums (ent->absmin, ent->absmax,
        leafs, MAX_TOTAL_ENT_LEAFS, &topnode);
 
    // set areas
    for (i=0 ; i<num_leafs ; i++)
    {
        clusters[i] = CM_LeafCluster (leafs[i]);
        area = CM_LeafArea (leafs[i]);
        if (area)
        {   // doors may legally straggle two areas,
            // but nothing should evern need more than that
            if (ent->areanum && ent->areanum != area)
            {
                if (ent->areanum2 && ent->areanum2 != area && sv.state == ss_loading)
                    Com_DPrintf ("Object touching 3 areas at %f %f %f\n",
                    ent->absmin[0], ent->absmin[1], ent->absmin[2]);
                ent->areanum2 = area;
            }
            else
                ent->areanum = area;
        }
    }
 
    if (num_leafs >= MAX_TOTAL_ENT_LEAFS)
    {   // assume we missed some leafs, and mark by headnode
        ent->num_clusters = -1;
        ent->headnode = topnode;
    }
    else
    {
        ent->num_clusters = 0;
        for (i=0 ; i<num_leafs ; i++)
        {
            if (clusters[i] == -1)
                continue;       // not a visible leaf
            for (j=0 ; j<i ; j++)
                if (clusters[j] == clusters[i])
                    break;
            if (j == i)
            {
                if (ent->num_clusters == MAX_ENT_CLUSTERS)
                {   // assume we missed some leafs, and mark by headnode
                    ent->num_clusters = -1;
                    ent->headnode = topnode;
                    break;
                }
 
                ent->clusternums[ent->num_clusters++] = clusters[i];
            }
        }
    }
 
    // if first time, make sure old_origin is valid
    if (!ent->linkcount)
    {
        VectorCopy (ent->s.origin, ent->s.old_origin);
    }
    ent->linkcount++;
 
    if (ent->solid == SOLID_NOT)
        return;
 
// find the first node that the ent's box crosses
    node = sv_areanodes;
    while (1)
    {
        if (node->axis == -1)
            break;
        if (ent->absmin[node->axis] > node->dist)
            node = node->children[0];
        else if (ent->absmax[node->axis] < node->dist)
            node = node->children[1];
        else
            break;      // crosses the node
    }
    
    // link it in   
    if (ent->solid == SOLID_TRIGGER)
        InsertLinkBefore (&ent->area, &node->trigger_edicts);
    else
        InsertLinkBefore (&ent->area, &node->solid_edicts);
 
}
 
 
/*
====================
SV_AreaEdicts_r
 
====================
*/
void SV_AreaEdicts_r (areanode_t *node)
{
    link_t      *l, *next, *start;
    edict_t     *check;
    int         count;
 
    count = 0;
 
    // touch linked edicts
    if (area_type == AREA_SOLID)
        start = &node->solid_edicts;
    else
        start = &node->trigger_edicts;
 
    for (l=start->next  ; l != start ; l = next)
    {
        next = l->next;
        check = EDICT_FROM_AREA(l);
 
        if (check->solid == SOLID_NOT)
            continue;       // deactivated
        if (check->absmin[0] > area_maxs[0]
        || check->absmin[1] > area_maxs[1]
        || check->absmin[2] > area_maxs[2]
        || check->absmax[0] < area_mins[0]
        || check->absmax[1] < area_mins[1]
        || check->absmax[2] < area_mins[2])
            continue;       // not touching
 
        if (area_count == area_maxcount)
        {
            Com_Printf ("SV_AreaEdicts: MAXCOUNT\n");
            return;
        }
 
        area_list[area_count] = check;
        area_count++;
    }
    
    if (node->axis == -1)
        return;     // terminal node
 
    // recurse down both sides
    if ( area_maxs[node->axis] > node->dist )
        SV_AreaEdicts_r ( node->children[0] );
    if ( area_mins[node->axis] < node->dist )
        SV_AreaEdicts_r ( node->children[1] );
}
 
/*
================
SV_AreaEdicts
================
*/
int SV_AreaEdicts (vec3_t mins, vec3_t maxs, edict_t **list,
    int maxcount, int areatype)
{
    area_mins = mins;
    area_maxs = maxs;
    area_list = list;
    area_count = 0;
    area_maxcount = maxcount;
    area_type = areatype;
 
    SV_AreaEdicts_r (sv_areanodes);
 
    return area_count;
}
 
 
//===========================================================================
 
/*
=============
SV_PointContents
=============
*/
int SV_PointContents (vec3_t p)
{
    edict_t     *touch[MAX_EDICTS], *hit;
    int         i, num;
    int         contents, c2;
    int         headnode;
    float       *angles;
 
    // get base contents from world
    contents = CM_PointContents (p, sv.models[1]->headnode);
 
    // or in contents from all the other entities
    num = SV_AreaEdicts (p, p, touch, MAX_EDICTS, AREA_SOLID);
 
    for (i=0 ; i<num ; i++)
    {
        hit = touch[i];
 
        // might intersect, so do an exact clip
        headnode = SV_HullForEntity (hit);
        angles = hit->s.angles;
        if (hit->solid != SOLID_BSP)
            angles = vec3_origin;   // boxes don't rotate
 
        c2 = CM_TransformedPointContents (p, headnode, hit->s.origin, hit->s.angles);
 
        contents |= c2;
    }
 
    return contents;
}
 
 
 
typedef struct
{
    vec3_t      boxmins, boxmaxs;// enclose the test object along entire move
    float       *mins, *maxs;   // size of the moving object
    vec3_t      mins2, maxs2;   // size when clipping against mosnters
    float       *start, *end;
    trace_t     trace;
    edict_t     *passedict;
    int         contentmask;
} moveclip_t;
 
 
 
/*
================
SV_HullForEntity
 
Returns a headnode that can be used for testing or clipping an
object of mins/maxs size.
Offset is filled in to contain the adjustment that must be added to the
testing object's origin to get a point to use with the returned hull.
================
*/
int SV_HullForEntity (edict_t *ent)
{
    cmodel_t    *model;
 
// decide which clipping hull to use, based on the size
    if (ent->solid == SOLID_BSP)
    {   // explicit hulls in the BSP model
        model = sv.models[ ent->s.modelindex ];
 
        if (!model)
            Com_Error (ERR_FATAL, "MOVETYPE_PUSH with a non bsp model");
 
        return model->headnode;
    }
 
    // create a temp hull from bounding box sizes
 
    return CM_HeadnodeForBox (ent->mins, ent->maxs);
}
 
 
//===========================================================================
 
/*
====================
SV_ClipMoveToEntities
 
====================
*/
void SV_ClipMoveToEntities ( moveclip_t *clip )
{
    int         i, num;
    edict_t     *touchlist[MAX_EDICTS], *touch;
    trace_t     trace;
    int         headnode;
    float       *angles;
 
    num = SV_AreaEdicts (clip->boxmins, clip->boxmaxs, touchlist
        , MAX_EDICTS, AREA_SOLID);
 
    // be careful, it is possible to have an entity in this
    // list removed before we get to it (killtriggered)
    for (i=0 ; i<num ; i++)
    {
        touch = touchlist[i];
        if (touch->solid == SOLID_NOT)
            continue;
        if (touch == clip->passedict)
            continue;
        if (clip->trace.allsolid)
            return;
        if (clip->passedict)
        {
            if (touch->owner == clip->passedict)
                continue;   // don't clip against own missiles
            if (clip->passedict->owner == touch)
                continue;   // don't clip against owner
        }
 
        if ( !(clip->contentmask & CONTENTS_DEADMONSTER)
        && (touch->svflags & SVF_DEADMONSTER) )
                continue;
 
        // might intersect, so do an exact clip
        headnode = SV_HullForEntity (touch);
        angles = touch->s.angles;
        if (touch->solid != SOLID_BSP)
            angles = vec3_origin;   // boxes don't rotate
 
        if (touch->svflags & SVF_MONSTER)
            trace = CM_TransformedBoxTrace (clip->start, clip->end,
                clip->mins2, clip->maxs2, headnode, clip->contentmask,
                touch->s.origin, angles);
        else
            trace = CM_TransformedBoxTrace (clip->start, clip->end,
                clip->mins, clip->maxs, headnode,  clip->contentmask,
                touch->s.origin, angles);
 
        if (trace.allsolid || trace.startsolid ||
        trace.fraction < clip->trace.fraction)
        {
            trace.ent = touch;
            if (clip->trace.startsolid)
            {
                clip->trace = trace;
                clip->trace.startsolid = true;
            }
            else
                clip->trace = trace;
        }
        else if (trace.startsolid)
            clip->trace.startsolid = true;
    }
}
 
 
/*
==================
SV_TraceBounds
==================
*/
void SV_TraceBounds (vec3_t start, vec3_t mins, vec3_t maxs, vec3_t end, vec3_t boxmins, vec3_t boxmaxs)
{
#if 0
// debug to test against everything
boxmins[0] = boxmins[1] = boxmins[2] = -9999;
boxmaxs[0] = boxmaxs[1] = boxmaxs[2] = 9999;
#else
    int     i;
    
    for (i=0 ; i<3 ; i++)
    {
        if (end[i] > start[i])
        {
            boxmins[i] = start[i] + mins[i] - 1;
            boxmaxs[i] = end[i] + maxs[i] + 1;
        }
        else
        {
            boxmins[i] = end[i] + mins[i] - 1;
            boxmaxs[i] = start[i] + maxs[i] + 1;
        }
    }
#endif
}
 
/*
==================
SV_Trace
 
Moves the given mins/maxs volume through the world from start to end.
 
Passedict and edicts owned by passedict are explicitly not checked.
 
==================
*/
trace_t SV_Trace (vec3_t start, vec3_t mins, vec3_t maxs, vec3_t end, edict_t *passedict, int contentmask)
{
    moveclip_t  clip;
 
    if (!mins)
        mins = vec3_origin;
    if (!maxs)
        maxs = vec3_origin;
 
    memset ( &clip, 0, sizeof ( moveclip_t ) );
 
    // clip to world
    clip.trace = CM_BoxTrace (start, end, mins, maxs, 0, contentmask);
    clip.trace.ent = ge->edicts;
    if (clip.trace.fraction == 0)
        return clip.trace;      // blocked by the world
 
    clip.contentmask = contentmask;
    clip.start = start;
    clip.end = end;
    clip.mins = mins;
    clip.maxs = maxs;
    clip.passedict = passedict;
 
    VectorCopy (mins, clip.mins2);
    VectorCopy (maxs, clip.maxs2);
    
    // create the bounding box of the entire move
    SV_TraceBounds ( start, clip.mins2, clip.maxs2, end, clip.boxmins, clip.boxmaxs );
 
    // clip to other solid entities
    SV_ClipMoveToEntities ( &clip );
 
    return clip.trace;
}