bsp.cpp

Go to the documentation of this file.

/*
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.

*/

#include "common.h"
#include "qfiles.h"
#include "tracing.h"
#include "routing.h"
#include "../shared/parse.h"

static cBspSurface_t nullSurface;

/*
===============================================================================
MAP LOADING
===============================================================================
*/

static int CMod_ValidateLump (const lump_t* lump, const char* functionName, size_t elementSize, const char* elementName, int elementMaxCount)
{
    if (!lump)
        Com_Error(ERR_DROP, "%s: No lump given", functionName);
    if (lump->filelen % elementSize)
        Com_Error(ERR_DROP, "%s: funny lump size (%i => " UFO_SIZE_T ")", functionName, lump->filelen, elementSize);
    const int count = lump->filelen / elementSize;
    Com_DPrintf(DEBUG_ENGINE, S_COLOR_GREEN "...%s: %i\n", elementName, count);

    if (count < 1)
        Com_Error(ERR_DROP, "Map with no %s", elementName);
    if (count > elementMaxCount)
        Com_Error(ERR_DROP, "Map has too many %s: %i", elementName, count);

    return count;
}

static void CMod_LoadSubmodels (MapTile& tile, const byte* base, const lump_t* lump, const vec3_t shift)
{
    const int count = CMod_ValidateLump(lump, __FUNCTION__, sizeof(dBspModel_t), "models", MAX_MAP_MODELS);

    const dBspModel_t* in = (const dBspModel_t*) (base + lump->fileofs);

    cBspModel_t* out = Mem_PoolAllocTypeN(cBspModel_t, count + 6, com_cmodelSysPool);
    tile.models = out;
    tile.nummodels = count;

    for (int i = 0; i < count; i++, in++, out++) {
        /* Record the shift in case we need to undo it. */
        VectorCopy(shift, out->shift);
        /* spread the mins / maxs by a pixel */
        out->cbmBox.setFromLittleFloat(in->dbmBox);
        out->cbmBox.expand(1);
        out->cbmBox.shift(shift);
        out->headnode = LittleLong(in->headnode);
        out->tile = tile.idx; /* backlink to the loaded map tile */
    }
}


static void CMod_LoadSurfaces (MapTile& tile, const byte* base, const lump_t* lump)
{
    const int count = CMod_ValidateLump(lump, __FUNCTION__, sizeof(dBspTexinfo_t), "surfaces", MAX_MAP_TEXINFO);

    const dBspTexinfo_t* in = (const dBspTexinfo_t*) (base + lump->fileofs);

    cBspSurface_t* out = Mem_PoolAllocTypeN(cBspSurface_t, count, com_cmodelSysPool);

    tile.surfaces = out;
    tile.numtexinfo = count;

    for (int i = 0; i < count; i++, in++, out++) {
        Q_strncpyz(out->name, in->texture, sizeof(out->name));
        out->surfaceFlags = LittleLong(in->surfaceFlags);
    }
}


static void CMod_LoadNodes (MapTile& tile, const byte* base, const lump_t* lump, const vec3_t shift)
{
    const int count = CMod_ValidateLump(lump, __FUNCTION__, sizeof(dBspNode_t), "nodes", MAX_MAP_NODES);

    const dBspNode_t* in = (const dBspNode_t*) (base + lump->fileofs);

    /* add some for the box */
    cBspNode_t* out = Mem_PoolAllocTypeN(cBspNode_t, count + 6, com_cmodelSysPool);

    tile.numnodes = count;
    tile.nodes = out;

    for (int i = 0; i < count; i++, out++, in++) {
        if (LittleLong(in->planenum) == PLANENUM_LEAF)
            out->plane = nullptr;
        else
            out->plane = tile.planes + LittleLong(in->planenum);

        /* in case this is a map assemble */
        for (int j = 0; j < 3; j++) {
            out->mins[j] = LittleShort(in->mins[j]) + shift[j];
            out->maxs[j] = LittleShort(in->maxs[j]) + shift[j];
        }

        for (int j = 0; j < 2; j++) {
            int child = LittleLong(in->children[j]);
            out->children[j] = child;
        }
    }
}

static void CMod_LoadBrushes (MapTile& tile, const byte* base, const lump_t* lump)
{
    const int count = CMod_ValidateLump(lump, __FUNCTION__, sizeof(dBspBrush_t), "brushes", MAX_MAP_BRUSHES);

    const dBspBrush_t* in = (const dBspBrush_t*) (base + lump->fileofs);

    /* add some for the box */
    cBspBrush_t* out = Mem_PoolAllocTypeN(cBspBrush_t, count + 1, com_cmodelSysPool);

    tile.numbrushes = count;
    tile.brushes = out;

    for (int i = 0; i < count; i++, out++, in++) {
        out->firstbrushside = LittleLong(in->firstbrushside);
        out->numsides = LittleLong(in->numsides);
        out->brushContentFlags = LittleLong(in->brushContentFlags);
    }
}

static void CMod_LoadLeafs (MapTile& tile, const byte* base, const lump_t* lump)
{
    const int count = CMod_ValidateLump(lump, __FUNCTION__, sizeof(dBspLeaf_t), "leafs", MAX_MAP_LEAFS);

    const dBspLeaf_t* in = (const dBspLeaf_t*) (base + lump->fileofs);

    /* add some for the box */
    cBspLeaf_t* out = Mem_PoolAllocTypeN(cBspLeaf_t, count + 1, com_cmodelSysPool);

    tile.numleafs = count;
    tile.leafs = out;

    for (int i = 0; i < count; i++, in++, out++) {
        out->contentFlags = LittleLong(in->contentFlags);
        out->firstleafbrush = LittleShort(in->firstleafbrush);
        out->numleafbrushes = LittleShort(in->numleafbrushes);
    }

    if (tile.leafs[0].contentFlags != CONTENTS_SOLID)
        Com_Error(ERR_DROP, "Map leaf 0 is not CONTENTS_SOLID");
    tile.emptyleaf = -1;
    for (int i = 1; i < tile.numleafs; i++) {
        if (!tile.leafs[i].contentFlags) {
            tile.emptyleaf = i;
            break;
        }
    }
    if (tile.emptyleaf == -1)
        Com_Error(ERR_DROP, "Map does not have an empty leaf");
}

static void CMod_LoadPlanes (MapTile& tile, const byte* base, const lump_t* lump, const vec3_t shift)
{
    const int count = CMod_ValidateLump(lump, __FUNCTION__, sizeof(dBspPlane_t), "planes", MAX_MAP_PLANES);

    const dBspPlane_t* in = (const dBspPlane_t*) (base + lump->fileofs);

    /* add some for the box */
    cBspPlane_t* out = Mem_PoolAllocTypeN(cBspPlane_t, count + 12, com_cmodelSysPool);

    tile.numplanes = count;
    tile.planes = out;

    for (int i = 0; i < count; i++, in++, out++) {
        out->dist = LittleFloat(in->dist);
        out->type = LittleLong(in->type);

        /* load normals and shift (map assembly) */
        for (int j = 0; j < 3; j++) {
            out->normal[j] = LittleFloat(in->normal[j]);
            out->dist += out->normal[j] * shift[j];
        }
    }
}

static void CMod_LoadLeafBrushes (MapTile& tile, const byte* base, const lump_t* lump)
{
    const int count = CMod_ValidateLump(lump, __FUNCTION__, sizeof(unsigned short), "leafbrushes", MAX_MAP_LEAFBRUSHES);

    const unsigned short* in = (const unsigned short*) (base + lump->fileofs);

    /* add some for the box */
    unsigned short* out = Mem_PoolAllocTypeN(unsigned short, count + 1, com_cmodelSysPool);

    tile.numleafbrushes = count;
    tile.leafbrushes = out;

    for (int i = 0; i < count; i++, in++, out++)
        *out = LittleShort(*in);
}

static void CMod_LoadBrushSides (MapTile& tile, const byte* base, const lump_t* lump)
{
    const int count = CMod_ValidateLump(lump, __FUNCTION__, sizeof(dBspBrushSide_t), "brushsides", MAX_MAP_BRUSHSIDES);

    const dBspBrushSide_t* in = (const dBspBrushSide_t*) (base + lump->fileofs);

    /* add some for the box */
    cBspBrushSide_t* out = Mem_PoolAllocTypeN(cBspBrushSide_t, count + 6, com_cmodelSysPool);

    tile.numbrushsides = count;
    tile.brushsides = out;

    for (int i = 0; i < count; i++, in++, out++) {
        const int num = LittleShort(in->planenum);
        const int j = LittleShort(in->texinfo);
        if (j >= tile.numtexinfo)
            Com_Error(ERR_DROP, "Bad brushside texinfo");
        out->plane = &tile.planes[num];
        out->surface = &tile.surfaces[j];
    }
}

static int CMod_DeCompressRouting (const byte**  source, byte*  dataStart)
{
    byte* data_p = dataStart;
    const byte* src = *source;

    while (*src) {
        int c;

        if (*src & 0x80) {
            /* repetitions */
            c = *src++ & ~0x80;
            /* Remember that the total bytes that are the same is c + 2 */
            for (int i = 0; i < c + 2; i++)
                *data_p++ = *src;
            src++;
        } else {
            /* identities */
            c = *src++;
            for (int i = 0; i < c; i++)
                *data_p++ = *src++;
        }
    }

    src++;
    *source = src;

    return data_p - dataStart;
}

/*
===============================================================================
TRACING NODES
===============================================================================
*/

static void CM_MakeTracingNodes (MapTile& tile)
{
    tnode_t* tnode = tile.tnodes = Mem_PoolAllocTypeN(tnode_t, tile.numnodes + 6, com_cmodelSysPool);

    tile.numtheads = 0;
    tile.numcheads = 0;

    for (int i = 0; i < tile.nummodels; i++) {
        if (tile.models[i].headnode == LEAFNODE || tile.models[i].headnode >= tile.numnodes + 6)
            continue;

        tile.thead[tile.numtheads] = tnode - tile.tnodes;
        tile.theadlevel[tile.numtheads] = i;
        tile.numtheads++;
        assert(tile.numtheads < LEVEL_MAX);

        /* If this level (i) is the last visible level or earlier, then trace it.
         * Otherwise don't; we have separate checks for entities. */
        if (i < NUM_REGULAR_MODELS)
            TR_BuildTracingNode_r(&tile, &tnode, tile.models[i].headnode, i);
    }
}

static void CMod_LoadRouting (MapTile& tile, mapData_t* mapData, const byte* base, const char* name, const lump_t* lump, const int sX, const int sY, const int sZ)
{
    Routing* tempMap = static_cast<Routing*>(Mem_Alloc(sizeof(Routing)));
    const int targetLength = sizeof(tile.wpMins) + sizeof(tile.wpMaxs) + sizeof(Routing);

    double start = time(nullptr);

    if (!lump)
        Com_Error(ERR_DROP, "CMod_LoadRouting: No lump given");

    if (!lump->filelen)
        Com_Error(ERR_DROP, "CMod_LoadRouting: Map has NO routing lump");

    assert((sX > -(PATHFINDING_WIDTH / 2)) && (sX < (PATHFINDING_WIDTH / 2)));
    assert((sY > -(PATHFINDING_WIDTH / 2)) && (sY < (PATHFINDING_WIDTH / 2)));
    assert((sZ >= 0) && (sZ < PATHFINDING_HEIGHT));

    const byte* source = base + lump->fileofs;

    int length = CMod_DeCompressRouting(&source, (byte*)tile.wpMins);
    length += CMod_DeCompressRouting(&source, (byte*)tile.wpMaxs);
    length += CMod_DeCompressRouting(&source, (byte*)tempMap);

    if (length != targetLength)
        Com_Error(ERR_DROP, "CMod_LoadRouting: Map has BAD routing lump; expected %i got %i", targetLength, length);

    /* endian swap possibly necessary */
    for (int i = 0; i < 3; i++) {
        tile.wpMins[i] = LittleLong(tile.wpMins[i]);
        tile.wpMaxs[i] = LittleLong(tile.wpMaxs[i]);
    }

    Com_DPrintf(DEBUG_ROUTING, "Map:%s  Offset:(%i, %i, %i)\n", name, sX, sY, sZ);
    Com_DPrintf(DEBUG_ROUTING, "wpMins:(%i, %i, %i) wpMaxs:(%i, %i, %i)\n", tile.wpMins[0], tile.wpMins[1],
            tile.wpMins[2], tile.wpMaxs[0], tile.wpMaxs[1], tile.wpMaxs[2]);

    /* wpMins and wpMaxs have the map size data from the initial build.
     * Offset this by the given parameters so the stored values are in real coordinates. */
    tile.wpMins[0] += sX;
    tile.wpMins[1] += sY;
    tile.wpMins[2] += sZ;
    tile.wpMaxs[0] += sX;
    tile.wpMaxs[1] += sY;
    tile.wpMaxs[2] += sZ;

    Com_DPrintf(DEBUG_ROUTING, "Shifted wpMins:(%i, %i, %i) wpMaxs:(%i, %i, %i)\n", tile.wpMins[0],
            tile.wpMins[1], tile.wpMins[2], tile.wpMaxs[0], tile.wpMaxs[1], tile.wpMaxs[2]);

    /* Things that need to be done:
     * The floor, ceiling, and route data can be copied over from the map.
     * All data must be regenerated for cells with overlapping content or where new
     * model data is adjacent to a cell with existing model data. */

    /* Copy the routing information into our master table */
    const int minX = std::max(tile.wpMins[0], 0);
    const int minY = std::max(tile.wpMins[1], 0);
    const int minZ = std::max(tile.wpMins[2], 0);
    const int maxX = std::min(tile.wpMaxs[0], PATHFINDING_WIDTH - 1);
    const int maxY = std::min(tile.wpMaxs[1], PATHFINDING_WIDTH - 1);
    const int maxZ = std::min(tile.wpMaxs[2], PATHFINDING_HEIGHT - 1);

    assert(minX <= maxX);
    assert(minY <= maxY);
    assert(minZ <= maxZ);

    Com_DPrintf(DEBUG_ROUTING, "Tile bounds: (%i, %i, %i) to (%i, %i, %i)\n", minX, minY, minZ, maxX, maxY, maxZ);
    Com_DPrintf(DEBUG_ROUTING, "Source bounds: (%i, %i, %i) to (%i, %i, %i)\n", minX - sX, minY - sY, minZ - sZ,
            maxX - sX, maxY - sY, maxZ - sZ);

    for (actorSizeEnum_t size = 0; size < ACTOR_MAX_SIZE; size++)
        /* Adjust starting x and y by size to catch large actor cell overlap. */
        for (int y = minY - size; y <= maxY; y++)
            for (int x = minX - size; x <= maxX; x++) {
                /* Just incase x or y start negative. */
                if (x < 0 || y < 0)
                    continue;
                for (int z = minZ; z <= maxZ; z++) {
                    mapData->routing.copyPosData(*tempMap, size + 1, x, y, z, sX, sY, sZ);
                }
                /* Update the reroute table */
                if (!mapData->reroute[size][y][x]) {
                    mapData->reroute[size][y][x] = tile.idx + 1;
                } else {
                    mapData->reroute[size][y][x] = ROUTING_NOT_REACHABLE;
                }
            }

    Com_DPrintf(DEBUG_ROUTING, "Done copying data.\n");

    double end = time(nullptr);
    Com_DPrintf(DEBUG_ROUTING, "Loaded routing for tile %s in %5.1fs\n", name, end - start);

    Mem_Free(tempMap);
}


static void CMod_LoadEntityString (MapTile& tile, const char* entityString, mapData_t* mapData, const byte* base, const lump_t* l, const vec3_t shift)
{
    if (!l)
        Com_Error(ERR_DROP, "CMod_LoadEntityString: No lump given (entitystring: '%s')", entityString ? entityString : "none");

    if (!l->filelen)
        Com_Error(ERR_DROP, "CMod_LoadEntityString: Map has NO entity lump (offset: %u, length: %u, entitystring: '%s')", l->fileofs, l->filelen, entityString ? entityString : "none");

    if (l->filelen + 1 > MAX_MAP_ENTSTRING)
        Com_Error(ERR_DROP, "CMod_LoadEntityString: Map has too large entity lump (offset: %u, length: %u, entitystring: '%s')", l->fileofs, l->filelen, entityString ? entityString : "none");

    /* merge entitystring information */
    const char* es = (const char*) (base + l->fileofs);
    while (1) {
        cBspModel_t* model = nullptr;
        /* parse the opening brace */
        const char* token = Com_Parse(&es);
        if (!es)
            break;
        if (token[0] != '{')
            Com_Error(ERR_DROP, "CMod_LoadEntityString: found %s when expecting { (offset: %u, length: %u, remaining: '%s')", token, l->fileofs, l->filelen, es);

        /* new entity */
        Q_strcat(mapData->mapEntityString, sizeof(mapData->mapEntityString), "{ ");

        /* go through all the dictionary pairs */
        while (1) {
            /* parse key */
            token = Com_Parse(&es);
            if (token[0] == '}')
                break;
            if (!es)
                Com_Error(ERR_DROP, "CMod_LoadEntityString: EOF without closing brace");

            char keyname[256];
            Q_strncpyz(keyname, token, sizeof(keyname));

            /* parse value */
            token = Com_Parse(&es);
            if (!es)
                Com_Error(ERR_DROP, "CMod_LoadEntityString: EOF without closing brace");

            if (token[0] == '}')
                Com_Error(ERR_DROP, "CMod_LoadEntityString: closing brace without data for keyname %s", keyname);

            /* alter value, if needed */
            if (Q_streq(keyname, "origin")) {
                /* origins are shifted */
                vec3_t v;
                if (sscanf(token, "%f %f %f", &(v[0]), &(v[1]), &(v[2])) != 3)
                    Com_Error(ERR_DROP, "CMod_LoadEntityString: invalid origin token '%s' for keyname %s", token, keyname);
                VectorAdd(v, shift, v);
                Q_strcat(mapData->mapEntityString, sizeof(mapData->mapEntityString), "%s \"%f %f %f\" ", keyname, v[0], v[1], v[2]);
                /* If we have a model, then unadjust it's mins and maxs. */
                if (model) {
                    VectorSubtract(model->cbmBox.mins, shift, model->cbmBox.mins);
                    VectorSubtract(model->cbmBox.maxs, shift, model->cbmBox.maxs);
                    model = nullptr; /* reset it, or the next origin will shift it again */
                }
            } else if (Q_streq(keyname, "model") && token[0] == '*') {
                /* adapt inline model number */
                int num = atoi(token + 1);
                /* Get the model */
                model = &tile.models[NUM_REGULAR_MODELS + num - 1];
                /* Now update the model number to reflect prior tiles loaded. */
                num += mapData->numInline;
                Q_strcat(mapData->mapEntityString, sizeof(mapData->mapEntityString), "%s *%i ", keyname, num);
            } else if (Q_streq(keyname, "targetname") || Q_streq(keyname, "target")) {
                Q_strcat(mapData->mapEntityString, sizeof(mapData->mapEntityString), "%s \"%s-%i\" ", keyname, token, tile.idx);
            } else {
                if (Q_streq(keyname, "classname") && Q_streq(token, "worldspawn")) {
                    if (Q_strvalid(entityString))
                        Q_strcat(mapData->mapEntityString, sizeof(mapData->mapEntityString), "%s", entityString);
                }
                /* just store key and value */
                Q_strcat(mapData->mapEntityString, sizeof(mapData->mapEntityString), "%s \"%s\" ", keyname, token);
            }
        }

        /* finish entity */
        Q_strcat(mapData->mapEntityString, sizeof(mapData->mapEntityString), "} ");
    }
}

static void CMod_LoadLighting (MapTile& tile, const byte* base, const lump_t* lump)
{
    if (lump->filelen == 0)
        return;

    tile.lightdata = Mem_PoolAllocTypeN(byte, lump->filelen, com_cmodelSysPool);
    memcpy(tile.lightdata, base + lump->fileofs, lump->filelen);
}

static void CM_InitBoxHull (MapTile& tile)
{
    tile.box_headnode = tile.numnodes;
    tile.box_planes = &tile.planes[tile.numplanes];
    /* sanity check if you only use one maptile => no map assembly */
    if (tile.idx == 1 && (tile.numnodes + 6 > MAX_MAP_NODES
        || tile.numbrushes + 1 > MAX_MAP_BRUSHES
        || tile.numleafbrushes + 1 > MAX_MAP_LEAFBRUSHES
        || tile.numbrushsides + 6 > MAX_MAP_BRUSHSIDES
        || tile.numplanes + 12 > MAX_MAP_PLANES))
        Com_Error(ERR_DROP, "Not enough room for box tree");

    tile.box_brush = &tile.brushes[tile.numbrushes];
    tile.box_brush->numsides = 6;
    tile.box_brush->firstbrushside = tile.numbrushsides;
    tile.box_brush->brushContentFlags = CONTENTS_WEAPONCLIP;

    tile.box_leaf = &tile.leafs[tile.numleafs];
    tile.box_leaf->contentFlags = CONTENTS_WEAPONCLIP;
    tile.box_leaf->firstleafbrush = tile.numleafbrushes;
    tile.box_leaf->numleafbrushes = 1;

    tile.leafbrushes[tile.numleafbrushes] = tile.numbrushes;

    /* each side */
    for (int i = 0; i < 6; i++) {
        const int side = i & 1;

        /* brush sides */
        cBspBrushSide_t* s = &tile.brushsides[tile.numbrushsides + i];
        s->plane = tile.planes + (tile.numplanes + i * 2 + side);
        s->surface = &nullSurface;

        /* nodes */
        cBspNode_t* c = &tile.nodes[tile.box_headnode + i];
        c->plane = tile.planes + (tile.numplanes + i * 2);
        c->children[side] = -1 - tile.emptyleaf;
        if (i != 5)
            c->children[side ^ 1] = tile.box_headnode + i + 1;
        else
            c->children[side ^ 1] = LEAFNODE - tile.numleafs;

        /* planes */
        cBspPlane_t* p = &tile.box_planes[i * 2];
        p->type = i >> 1;
        VectorClear(p->normal);
        p->normal[i >> 1] = 1;

        p = &tile.box_planes[i * 2 + 1];
        p->type = PLANE_ANYX + (i >> 1);
        VectorClear(p->normal);
        p->normal[i >> 1] = -1;
    }
}

void CM_LoadBsp (MapTile& tile, const dBspHeader_t& header, const vec3_t shift, const byte* base)
{
    /* load into heap */
    CMod_LoadSurfaces(tile, base, &header.lumps[LUMP_TEXINFO]);
    CMod_LoadLeafs(tile, base, &header.lumps[LUMP_LEAFS]);
    CMod_LoadLeafBrushes(tile, base, &header.lumps[LUMP_LEAFBRUSHES]);
    CMod_LoadPlanes(tile, base, &header.lumps[LUMP_PLANES], shift);
    CMod_LoadBrushes(tile, base, &header.lumps[LUMP_BRUSHES]);
    CMod_LoadBrushSides(tile, base, &header.lumps[LUMP_BRUSHSIDES]);
    CMod_LoadSubmodels(tile, base, &header.lumps[LUMP_MODELS], shift);
    CMod_LoadNodes(tile, base, &header.lumps[LUMP_NODES], shift);
}

static void CM_AddMapTile (const char* name, const char* entityString, const bool day, const int sX, const int sY, const byte sZ, mapData_t* mapData, mapTiles_t* mapTiles)
{
    Com_DPrintf(DEBUG_ENGINE, "CM_AddMapTile: %s at %i,%i,%i\n", name, sX, sY, sZ);
    assert(name);
    assert(name[0]);
    assert((sX > -(PATHFINDING_WIDTH / 2)) && (sX < (PATHFINDING_WIDTH / 2)));
    assert((sY > -(PATHFINDING_WIDTH / 2)) && (sY < (PATHFINDING_WIDTH / 2)));
    assert(sZ < PATHFINDING_HEIGHT);

    /* load the file */
    char filename[MAX_QPATH];
    Com_sprintf(filename, sizeof(filename), "maps/%s.bsp", name);
    byte* buf;
    const int length = FS_LoadFile(filename, &buf);
    if (!buf)
        Com_Error(ERR_DROP, "Couldn't load %s", filename);

    const unsigned checksum = LittleLong(Com_BlockChecksum(buf, length));

    dBspHeader_t header = *(dBspHeader_t*) buf;
    BSP_SwapHeader(&header, filename);

    if (header.version != BSPVERSION)
        Com_Error(ERR_DROP, "CM_AddMapTile: %s has wrong version number (%i should be %i)", name, header.version, BSPVERSION);

    const byte* base = (const byte*) buf;

    /* init */
    if (mapTiles->numTiles >= MAX_MAPTILES)
        Com_Error(ERR_FATAL, "CM_AddMapTile: too many tiles loaded %i", mapTiles->numTiles);

    MapTile& tile = mapTiles->mapTiles[mapTiles->numTiles];
    OBJZERO(tile);
    tile.idx = mapTiles->numTiles;
    Q_strncpyz(tile.name, name, sizeof(tile.name));

    /* use for random map assembly for shifting origins and so on */
    vec3_t shift;
    /* pathfinding and the like must be shifted on the worldplane when we
     * are assembling a map */
    VectorSet(shift, sX * UNIT_SIZE, sY * UNIT_SIZE, sZ * UNIT_HEIGHT);

    CM_LoadBsp(tile, header, shift, base);
    CMod_LoadEntityString(tile, entityString, mapData, base, &header.lumps[LUMP_ENTITIES], shift);
    if (day)
        CMod_LoadLighting(tile, base, &header.lumps[LUMP_LIGHTING_DAY]);
    else
        CMod_LoadLighting(tile, base, &header.lumps[LUMP_LIGHTING_NIGHT]);

    CM_InitBoxHull(tile);
    CM_MakeTracingNodes(tile);

    mapData->numInline += tile.nummodels - NUM_REGULAR_MODELS;

    CMod_LoadRouting(tile, mapData, base, name, &header.lumps[LUMP_ROUTING], sX, sY, sZ);

    /* now increase the amount of loaded tiles */
    mapTiles->numTiles++;

    /* Now find the map bounds with the updated numTiles. */
    /* calculate new border after merge */
    RT_GetMapSize(mapTiles, mapData->mapBox);

    FS_FreeFile(buf);

    mapData->mapChecksum += checksum;
}

static void CMod_RerouteMap (mapTiles_t* mapTiles, mapData_t* mapData)
{
    int x, y, z;
    int cols = 0;
    /* stopwatch */
    const double start = time(nullptr);

    GridBox rBox(mapData->mapBox);  /* the box we will actually reroute */
    rBox.clipToMaxBoundaries();

    /* First, close the borders of the map. This is needed once we produce tiles with open borders.
     * It's done by setting the connection (height) to 0 */
    for (actorSizeEnum_t actorSize = 1; actorSize <= ACTOR_MAX_SIZE; actorSize++) {
        for (z = rBox.getMinZ(); z <= rBox.getMaxZ(); z++) {
            for (y = rBox.getMinY(); y <= rBox.getMaxY(); y++) {
                x = rBox.getMinX();
                mapData->routing.setConn(actorSize, x, y, z, 6, 0); /* NX-PY */
                mapData->routing.setConn(actorSize, x, y, z, 1, 0); /* NX */
                mapData->routing.setConn(actorSize, x, y, z, 5, 0); /* NX-NY */
                x = rBox.getMaxX();
                mapData->routing.setConn(actorSize, x, y, z, 4, 0); /* PX-PY */
                mapData->routing.setConn(actorSize, x, y, z, 0, 0); /* PX */
                mapData->routing.setConn(actorSize, x, y, z, 7, 0); /* PX-NY */
            }
            for (x = rBox.getMinX(); x <= rBox.getMaxX(); x++) {
                y = rBox.getMinY();
                mapData->routing.setConn(actorSize, x, y, z, 5, 0); /* NY-NX */
                mapData->routing.setConn(actorSize, x, y, z, 3, 0); /* NY */
                mapData->routing.setConn(actorSize, x, y, z, 7, 0); /* NY-PX */
                y = rBox.getMaxY();
                mapData->routing.setConn(actorSize, x, y, z, 6, 0); /* PY-NX */
                mapData->routing.setConn(actorSize, x, y, z, 2, 0); /* PY */
                mapData->routing.setConn(actorSize, x, y, z, 4, 0); /* PY-PX */
            }
        }
    }

    /* Floor pass */
    for (actorSizeEnum_t actorSize = ACTOR_SIZE_INVALID; actorSize < ACTOR_MAX_SIZE; actorSize++) {
        for (y = rBox.getMinY(); y <= rBox.getMaxY(); y++) {
            for (x = rBox.getMinX(); x <= rBox.getMaxX(); x++) {
                if (mapData->reroute[actorSize][y][x] == ROUTING_NOT_REACHABLE) {
                    cols++;
                    for (z = rBox.getMaxZ(); z >= rBox.getMinZ(); z--) {
                        const int newZ = RT_CheckCell(mapTiles, mapData->routing, actorSize + 1, x, y, z, nullptr);
                        assert(newZ <= z);
                        z = newZ;
                    }
                }
            }
        }
    }

    /* Wall pass */
    for (actorSizeEnum_t actorSize = ACTOR_SIZE_INVALID; actorSize < ACTOR_MAX_SIZE; actorSize++) {
        for (y = rBox.getMinY(); y <= rBox.getMaxY(); y++) {
            for (x = rBox.getMinX(); x <= rBox.getMaxX(); x++) {
                const byte tile = mapData->reroute[actorSize][y][x];
                if (tile) {
                    byte fromTile1 = 0;
                    byte fromTile2 = 0;
                    byte fromTile3 = 0;
                    mapTiles->getTilesAt(x ,y, fromTile1, fromTile2, fromTile3);
                    for (int dir = 0; dir < CORE_DIRECTIONS; dir++) {
                        const int dx = x + dvecs[dir][0];
                        const int dy = y + dvecs[dir][1];
                        /* Skip if the destination is out of bounds. */
                        if (dx < 0 || dx >= PATHFINDING_WIDTH || dy < 0 || dy >= PATHFINDING_WIDTH)
                            continue;
                        const int tile2 = mapData->reroute[actorSize][dy][dx];
                        /* Both cells are present and if either cell is ROUTING_NOT_REACHABLE or if the cells are different. */
                        if (tile2 && (tile2 == ROUTING_NOT_REACHABLE || tile2 != tile)) {
#if 0   // this causes problems eg. at baseattack entrance (see bug 5292). Disabled until the underlying problem is found
                            byte toTile1 = 0;
                            byte toTile2 = 0;
                            byte toTile3 = 0;
                            mapTiles->getTilesAt(dx ,dy, toTile1, toTile2, toTile3);

                            int minZ = 0;
                            int maxZ = PATHFINDING_HEIGHT;
                            if (fromTile1 == toTile1) {         /* same tile */
                                if (fromTile2 && toTile2) {     /* and there are stacked tiles */
                                    if (fromTile2 == toTile2) { /* the stacked tiles are also the same */
                                        mapTiles->getTileOverlap(toTile1, toTile2, minZ, maxZ); /* reduce the z-range to reroute */
                                    }
                                }
                            }
                            RT_UpdateConnectionColumn(mapTiles, mapData->routing, actorSize + 1, x, y, dir, nullptr, minZ, maxZ);
#else
                            RT_UpdateConnectionColumn(mapTiles, mapData->routing, actorSize + 1, x, y, dir);
#endif // 1
                        }
                    }
                }
            }
        }
    }
    const double end = time(nullptr);
    Com_Printf("Rerouted %i cols for RMA in %5.1fs\n", cols, end - start);
}

void CM_LoadMap (const char* tiles, bool day, const char* pos, const char* entityString, mapData_t* mapData, mapTiles_t* mapTiles)
{
    char name[MAX_VAR];
    char base[MAX_QPATH];

    Mem_FreePool(com_cmodelSysPool);

    /* init */
    base[0] = 0;

    /* Reset the map related data */
    OBJZERO(*mapData);
    OBJZERO(*mapTiles);

    /* load tiles */
    while (tiles) {
        /* get tile name */
        const char* token = Com_Parse(&tiles);
        if (!tiles) {
            CMod_RerouteMap(mapTiles, mapData);
            return;
        }

        /* get base path */
        if (token[0] == '-') {
            Q_strncpyz(base, token + 1, sizeof(base));
            continue;
        }

        /* get tile name */
        Com_DPrintf(DEBUG_ENGINE, "CM_LoadMap: token: %s\n", token);
        if (token[0] == '+')
            Com_sprintf(name, sizeof(name), "%s%s", base, token + 1);
        else
            Q_strncpyz(name, token, sizeof(name));

        if (pos && pos[0]) {
            ipos3_t sh;
            /* get position and add a tile */
            for (int i = 0; i < 3; i++) {
                token = Com_Parse(&pos);
                if (!pos)
                    Com_Error(ERR_DROP, "CM_LoadMap: invalid positions");
                sh[i] = atoi(token);
            }
            if (sh[0] <= -(PATHFINDING_WIDTH / 2) || sh[0] >= PATHFINDING_WIDTH / 2)
                Com_Error(ERR_DROP, "CM_LoadMap: invalid x position given: %i\n", sh[0]);
            if (sh[1] <= -(PATHFINDING_WIDTH / 2) || sh[1] >= PATHFINDING_WIDTH / 2)
                Com_Error(ERR_DROP, "CM_LoadMap: invalid y position given: %i\n", sh[1]);
            if (sh[2] >= PATHFINDING_HEIGHT)
                Com_Error(ERR_DROP, "CM_LoadMap: invalid z position given: %i\n", sh[2]);
            CM_AddMapTile(name, entityString, day, sh[0], sh[1], sh[2], mapData, mapTiles);
        } else {
            /* load only a single tile, if no positions are specified */
            CM_AddMapTile(name, entityString, day, 0, 0, 0, mapData, mapTiles);
            return;
        }
    }

    Com_Error(ERR_DROP, "CM_LoadMap: invalid tile names");
}

cBspModel_t* CM_InlineModel (const mapTiles_t* mapTiles, const char* name)
{
    /* we only want inline models here */
    if (!name || name[0] != '*')
        Com_Error(ERR_DROP, "CM_InlineModel: bad name: '%s'", name ? name : "");
    /* skip the '*' character and get the inline model number */
    int num = atoi(name + 1) - 1;
    if (num < 0 || num >= MAX_MODELS)
        Com_Error(ERR_DROP, "CM_InlineModel: bad number %i - max inline models are %i", num, MAX_MODELS);

    /* search all the loaded tiles for the given inline model */
    for (int i = 0; i < mapTiles->numTiles; i++) {
        const int models = mapTiles->mapTiles[i].nummodels - NUM_REGULAR_MODELS;
        assert(models >= 0);

        if (num >= models)
            num -= models;
        else
            return &(mapTiles->mapTiles[i].models[NUM_REGULAR_MODELS + num]);
    }

    Com_Error(ERR_DROP, "CM_InlineModel: Error cannot find model '%s'\n", name);
}

cBspModel_t* CM_SetInlineModelOrientation (mapTiles_t* mapTiles, const char* name, const vec3_t origin, const vec3_t angles)
{
    cBspModel_t* model = CM_InlineModel(mapTiles, name);
    assert(model);
    VectorCopy(origin, model->origin);
    VectorCopy(angles, model->angles);

    return model;
}

void CM_GetInlineModelAABB (mapTiles_t* mapTiles, const char* name, AABB& aabb)
{
    const cBspModel_t* model = CM_InlineModel(mapTiles, name);
    assert(model);
    CalculateMinsMaxs(model->angles, model->cbmBox, model->origin, aabb);
}

float CM_GetVisibility (const mapTiles_t* mapTiles, const pos3_t position)
{
    for (int i = 0; i < mapTiles->numTiles; i++) {
        const MapTile& tile = mapTiles->mapTiles[i];
        if (VectorInside(position, tile.wpMins, tile.wpMaxs)) {
            if (tile.lightdata == nullptr)
                return 1.0f;
            return 1.0f;
        }
    }

    /* point is outside of any loaded tile */
    Com_Printf("given point %i:%i:%i is not inside of any loaded tile\n", position[0], position[1], position[2]);
    return 1.0f;
}