/* Copyright (C) 2002-2003 Charles Hollemeersch 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. PENTA: Quake 3 collision/areaportals code Heavily based on the public quake2 source */ #include "quakedef.h" mplane_t *box_planes; int box_firstbrush; mbrush_t *box_brush; #define M sv.worldmodel //timestamp variables int c_pointcontents = 0; int c_brush_traces = 0; int checkcount = 0; int c_traces = 0; /* =================== CM_InitBoxHull Set up the planes and nodes so that the six floats of a bounding box can just be stored out and get a proper clipping hull structure. =================== */ void CM_InitBoxHull (void) { int i; int side; mplane_t *p; mbrushside_t *s; box_planes = &M->planes[M->numplanes]; box_firstbrush = M->numbrushes; box_brush = &M->brushes[M->numbrushes]; box_brush->numsides = 6; box_brush->firstbrushside = M->numbrushsides; box_brush->contents = CONTENTS_EMPTY; for (i=0 ; i<6 ; i++) { side = i&1; // brush sides s = &M->brushsides[M->numbrushsides+i]; s->plane = M->planes + (M->numplanes+i*2+side); s->texture = NULL; // planes p = &box_planes[i*2]; p->type = i>>1; p->signbits = 0; VectorClear (p->normal); p->normal[i>>1] = 1; p = &box_planes[i*2+1]; p->type = 3 + (i>>1); p->signbits = 0; VectorClear (p->normal); p->normal[i>>1] = -1; } } /* =================== CM_HeadnodeForBox To keep everything totally uniform, bounding boxes are turned into small BSP trees instead of being compared directly. =================== *//* int CM_HeadnodeForBox (vec3_t mins, vec3_t maxs) { box_planes[0].dist = maxs[0]; box_planes[1].dist = -maxs[0]; box_planes[2].dist = mins[0]; box_planes[3].dist = -mins[0]; box_planes[4].dist = maxs[1]; box_planes[5].dist = -maxs[1]; box_planes[6].dist = mins[1]; box_planes[7].dist = -mins[1]; box_planes[8].dist = maxs[2]; box_planes[9].dist = -maxs[2]; box_planes[10].dist = mins[2]; box_planes[11].dist = -mins[2]; return box_headnode; } */ /* =================== CM_BrushForBox =================== */ int CM_BrushForBox (vec3_t mins, vec3_t maxs) { box_planes[0].dist = maxs[0]; box_planes[1].dist = -maxs[0]; box_planes[2].dist = mins[0]; box_planes[3].dist = -mins[0]; box_planes[4].dist = maxs[1]; box_planes[5].dist = -maxs[1]; box_planes[6].dist = mins[1]; box_planes[7].dist = -mins[1]; box_planes[8].dist = maxs[2]; box_planes[9].dist = -maxs[2]; box_planes[10].dist = mins[2]; box_planes[11].dist = -mins[2]; return box_firstbrush; } /* ================== CM_PointLeafnum_r ================== */ int CM_PointLeafnum_r (vec3_t p, int num) { float d; mnode_t *node; mplane_t *plane; while (num >= 0) { node = M->nodes + num; plane = node->plane; if (plane->type < 3) d = p[plane->type] - plane->dist; else d = DotProduct (plane->normal, p) - plane->dist; if (d < 0) num = node->ichildren[1]; else num = node->ichildren[0]; } c_pointcontents++; // optimize counter return -1 - num; } int CM_PointLeafnum (vec3_t p) { if (!M->numplanes) return 0; // sound may call this without map loaded return CM_PointLeafnum_r (p, 0); } /* ============= CM_BoxLeafnums Fills in a list of all the leafs touched ============= */ int leaf_count, leaf_maxcount; int *leaf_list; float *leaf_mins, *leaf_maxs; int leaf_topnode; void CM_BoxLeafnums_r (int nodenum) { mplane_t *plane; mnode_t *node; int s; while (1) { if (nodenum < 0) { if (leaf_count >= leaf_maxcount) { // Com_Printf ("CM_BoxLeafnums_r: overflow\n"); return; } leaf_list[leaf_count++] = -1 - nodenum; return; } node = &M->nodes[nodenum]; plane = node->plane; // s = BoxOnPlaneSide (leaf_mins, leaf_maxs, plane); s = BOX_ON_PLANE_SIDE(leaf_mins, leaf_maxs, plane); if (s == 1) nodenum = node->ichildren[0]; else if (s == 2) nodenum = node->ichildren[1]; else { // go down both if (leaf_topnode == -1) leaf_topnode = nodenum; CM_BoxLeafnums_r (node->ichildren[0]); nodenum = node->ichildren[1]; } } } int CM_BoxLeafnums_headnode (vec3_t mins, vec3_t maxs, int *list, int listsize, int headnode, int *topnode) { leaf_list = list; leaf_count = 0; leaf_maxcount = listsize; leaf_mins = mins; leaf_maxs = maxs; leaf_topnode = -1; CM_BoxLeafnums_r (headnode); if (topnode) *topnode = leaf_topnode; return leaf_count; } int CM_BoxLeafnums (vec3_t mins, vec3_t maxs, int *list, int listsize, int *topnode) { return CM_BoxLeafnums_headnode (mins, maxs, list, listsize, 0 /*headnode??*/, topnode); } /* ================== CM_PointContents ================== */ int CM_PointContents (vec3_t p, int headnode) { int l, contents, i, j; mleaf_t *leaf; mbrush_t *brush; mbrushside_t *brushside; if (!M->numnodes) // map not loaded return 0; l = CM_PointLeafnum_r (p, 0 /*headnode*/); //PENTA: Based on qfusion contents soucre leaf = &M->leafs[l]; if ( leaf->contents & CONTENTS_NODROP ) { contents = CONTENTS_NODROP; } else { contents = 0; } for (i = 0; i < leaf->numbrushes; i++) { brush = &M->brushes[M->leafbrushes[leaf->firstbrush + i]]; // check if brush actually adds something to contents if ( (contents & brush->contents) == brush->contents ) { continue; } brushside = &M->brushsides[brush->firstbrushside]; for ( j = 0; j < brush->numsides; j++, brushside++ ) { if ((DotProduct(p, brushside->plane->normal) -brushside->plane->dist) > 0) break; } if (j == brush->numsides) contents |= brush->contents; } return contents; } /* ================== CM_TransformedPointContents Handles offseting and rotation of the end points for moving and rotating entities ================== */ int CM_TransformedPointContents (vec3_t p, int headnode, vec3_t origin, vec3_t angles) { vec3_t p_l; vec3_t temp; vec3_t forward, right, up; int l; // subtract origin offset VectorSubtract (p, origin, p_l); // rotate start and end into the models frame of reference if (angles[0] || angles[1] || angles[2]) { AngleVectors (angles, forward, right, up); VectorCopy (p_l, temp); p_l[0] = DotProduct (temp, forward); p_l[1] = -DotProduct (temp, right); p_l[2] = DotProduct (temp, up); } l = CM_PointLeafnum_r (p_l, headnode); return M->leafs[l].contents; } /* =============================================================================== BOX TRACING =============================================================================== */ // 1/32 epsilon to keep floating point happy #define DIST_EPSILON (0.03125) vec3_t trace_start, trace_end; vec3_t trace_mins, trace_maxs; vec3_t trace_extents; trace_t trace_trace; int trace_contents; qboolean trace_ispoint; // optimized case /* ================ CM_ClipBoxToBrush ================ */ void CM_ClipBoxToBrush (vec3_t mins, vec3_t maxs, vec3_t p1, vec3_t p2, trace_t *trace, mbrush_t *brush) { int i, j; mplane_t *plane, *clipplane; float dist; float enterfrac, leavefrac; vec3_t ofs; float d1, d2; qboolean getout, startout; float f; mbrushside_t *side, *leadside; enterfrac = -1; leavefrac = 1; clipplane = NULL; if (!brush->numsides) return; c_brush_traces++; getout = false; startout = false; leadside = NULL; for (i=0 ; inumsides ; i++) { side = &M->brushsides[brush->firstbrushside+i]; plane = side->plane; // FIXME: special case for axial if (!trace_ispoint) { // general box case // push the plane out apropriately for mins/maxs // FIXME: use signbits into 8 way lookup for each mins/maxs for (j=0 ; j<3 ; j++) { if (plane->normal[j] < 0) ofs[j] = maxs[j]; else ofs[j] = mins[j]; } dist = DotProduct (ofs, plane->normal); dist = plane->dist - dist; } else { // special point case dist = plane->dist; } d1 = DotProduct (p1, plane->normal) - dist; d2 = DotProduct (p2, plane->normal) - dist; if (d2 > 0) getout = true; // endpoint is not in solid if (d1 > 0) startout = true; // if completely in front of face, no intersection if (d1 > 0 && d2 >= d1) return; if (d1 <= 0 && d2 <= 0) continue; // crosses face if (d1 > d2) { // enter f = (d1-DIST_EPSILON) / (d1-d2); if (f > enterfrac) { enterfrac = f; clipplane = plane; leadside = side; } } else { // leave f = (d1+DIST_EPSILON) / (d1-d2); if (f < leavefrac) leavefrac = f; } } if (!startout) { // original point was inside brush trace->startsolid = true; if (!getout) trace->allsolid = true; return; } if (enterfrac < leavefrac) { if (enterfrac > -1 && enterfrac < trace->fraction) { if (enterfrac < 0) enterfrac = 0; trace->fraction = enterfrac; //trace->plane = *clipplane; //trace->surface = &(leadside->surface->c); VectorCopy(clipplane->normal,trace->plane.normal); trace->plane.dist = clipplane->dist; //trace->contents = brush->contents; } } } /* ================ CM_TestBoxInBrush ================ */ void CM_TestBoxInBrush (vec3_t mins, vec3_t maxs, vec3_t p1, trace_t *trace, mbrush_t *brush) { int i, j; mplane_t *plane; float dist; vec3_t ofs; float d1; mbrushside_t *side; if (!brush->numsides) return; for (i=0 ; inumsides ; i++) { side = &M->brushsides[brush->firstbrushside+i]; plane = side->plane; // FIXME: special case for axial // general box case // push the plane out apropriately for mins/maxs // FIXME: use signbits into 8 way lookup for each mins/maxs for (j=0 ; j<3 ; j++) { if (plane->normal[j] < 0) ofs[j] = maxs[j]; else ofs[j] = mins[j]; } dist = DotProduct (ofs, plane->normal); dist = plane->dist - dist; d1 = DotProduct (p1, plane->normal) - dist; // if completely in front of face, no intersection if (d1 > 0) return; } // inside this brush trace->startsolid = trace->allsolid = true; trace->fraction = 0; //trace->contents = brush->contents; } /* ================ CM_TraceToLeaf ================ */ void CM_TraceToLeaf (int leafnum) { int k; int brushnum; mleaf_t *leaf; mbrush_t *b; leaf = &M->leafs[leafnum]; //if ( !(leaf->contents & trace_contents)) // return; // trace line against all brushes in the leaf for (k=0 ; knumbrushes ; k++) { brushnum = M->leafbrushes[leaf->firstbrush+k]; b = &M->brushes[brushnum]; /* Con_Printf("Checkbrush %i",brushnum); if (brushnum == 1800) { int j; for (j=0; jnumsides; j++) { Con_Printf("Side: %f %f %f %f\n",M->brushsides[j+b->firstbrushside].plane->normal[0], M->brushsides[j+b->firstbrushside].plane->normal[1], M->brushsides[j+b->firstbrushside].plane->normal[2], M->brushsides[j+b->firstbrushside].plane->dist); } } */ if (b->checkcount == checkcount) continue; // already checked this brush in another leaf b->checkcount = checkcount; if ( !(b->contents & trace_contents)) continue; CM_ClipBoxToBrush (trace_mins, trace_maxs, trace_start, trace_end, &trace_trace, b); if (!trace_trace.fraction) return; } } /* ================ CM_TraceToBrushModel PENTA: Clips to the given brush model Q3 doesn't have bsp's associated with map models anymore, just a list of brushes ================ */ void CM_TraceToBrushModel (int firstbrush, int numbrushes, vec3_t mins, vec3_t maxs, vec3_t start, vec3_t end, trace_t *trace, int brushmask) { int i, brushnum; mbrush_t *b; //Con_Printf("CM_TraceToBrushModel"); if (!M->numnodes) // map not loaded return; trace_contents = brushmask; trace_ispoint = false; for (i=0; ileafbrushes[firstbrush+i]; b = &M->brushes[firstbrush+i]; if ( !(b->contents & trace_contents)) continue; CM_ClipBoxToBrush (mins, maxs, start, end, trace, b); if (!trace->fraction) return; } if (trace->fraction == 1) { VectorCopy (end, trace->endpos); } else { for (i=0 ; i<3 ; i++) trace->endpos[i] = start[i] + trace->fraction * (end[i] - start[i]); } } /* ================ CM_TestInLeaf ================ */ void CM_TestInLeaf (int leafnum) { int k; int brushnum; mleaf_t *leaf; mbrush_t *b; leaf = &M->leafs[leafnum]; //if ( !(leaf->contents & trace_contents)) // return; // trace line against all brushes in the leaf for (k=0 ; knumbrushes ; k++) { brushnum = M->leafbrushes[leaf->firstbrush+k]; b = &M->brushes[brushnum]; if (b->checkcount == checkcount) continue; // already checked this brush in another leaf b->checkcount = checkcount; if ( !(b->contents & trace_contents)) continue; CM_TestBoxInBrush (trace_mins, trace_maxs, trace_start, &trace_trace, b); if (!trace_trace.fraction) return; } } /* ================== CM_RecursiveHullCheck ================== */ void CM_RecursiveHullCheck (int num, float p1f, float p2f, vec3_t p1, vec3_t p2) { mnode_t *node; mplane_t *plane; float t1, t2, offset; float frac, frac2; float idist; int i; vec3_t mid; int side; float midf; if (trace_trace.fraction <= p1f) return; // already hit something nearer // if < 0, we are in a leaf node if (num < 0) { CM_TraceToLeaf (-1-num); return; } // // find the point distances to the seperating plane // and the offset for the size of the box // node = M->nodes + num; plane = node->plane; if (plane->type < 3) { t1 = p1[plane->type] - plane->dist; t2 = p2[plane->type] - plane->dist; offset = trace_extents[plane->type]; } else { t1 = DotProduct (plane->normal, p1) - plane->dist; t2 = DotProduct (plane->normal, p2) - plane->dist; if (trace_ispoint) offset = 0; else offset = fabs(trace_extents[0]*plane->normal[0]) + fabs(trace_extents[1]*plane->normal[1]) + fabs(trace_extents[2]*plane->normal[2]); } #if 0 CM_RecursiveHullCheck (node->ichildren[0], p1f, p2f, p1, p2); CM_RecursiveHullCheck (node->ichildren[1], p1f, p2f, p1, p2); return; #endif // see which sides we need to consider if (t1 >= offset && t2 >= offset) { CM_RecursiveHullCheck (node->ichildren[0], p1f, p2f, p1, p2); return; } if (t1 < -offset && t2 < -offset) { CM_RecursiveHullCheck (node->ichildren[1], p1f, p2f, p1, p2); return; } // put the crosspoint DIST_EPSILON pixels on the near side if (t1 < t2) { idist = 1.0/(t1-t2); side = 1; frac2 = (t1 + offset + DIST_EPSILON)*idist; frac = (t1 - offset + DIST_EPSILON)*idist; } else if (t1 > t2) { idist = 1.0/(t1-t2); side = 0; frac2 = (t1 - offset - DIST_EPSILON)*idist; frac = (t1 + offset + DIST_EPSILON)*idist; } else { side = 0; frac = 1; frac2 = 0; } // move up to the node 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]); CM_RecursiveHullCheck (node->ichildren[side], p1f, midf, p1, mid); // go past the node if (frac2 < 0) frac2 = 0; if (frac2 > 1) frac2 = 1; midf = p1f + (p2f - p1f)*frac2; for (i=0 ; i<3 ; i++) mid[i] = p1[i] + frac2*(p2[i] - p1[i]); CM_RecursiveHullCheck (node->ichildren[side^1], midf, p2f, mid, p2); } //====================================================================== /* ================== CM_BoxTrace ================== */ trace_t CM_BoxTrace (vec3_t start, vec3_t end, vec3_t mins, vec3_t maxs, int headnode, int brushmask) { int i; // Con_Printf("CM_BoxTrace"); checkcount++; // for multi-check avoidance c_traces++; // for statistics, may be zeroed // fill in a default trace memset (&trace_trace, 0, sizeof(trace_trace)); trace_trace.fraction = 1; //trace_trace.surface = &(nullsurface.c); if (!M->numnodes) // map not loaded return trace_trace; trace_contents = brushmask; VectorCopy (start, trace_start); VectorCopy (end, trace_end); VectorCopy (mins, trace_mins); VectorCopy (maxs, trace_maxs); // // check for position test special case // if (start[0] == end[0] && start[1] == end[1] && start[2] == end[2]) { int leafs[1024]; int i, numleafs; vec3_t c1, c2; int topnode; VectorAdd (start, mins, c1); VectorAdd (start, maxs, c2); for (i=0 ; i<3 ; i++) { c1[i] -= 1; c2[i] += 1; } numleafs = CM_BoxLeafnums_headnode (c1, c2, leafs, 1024, headnode, &topnode); for (i=0 ; i maxs[0] ? -mins[0] : maxs[0]; trace_extents[1] = -mins[1] > maxs[1] ? -mins[1] : maxs[1]; trace_extents[2] = -mins[2] > maxs[2] ? -mins[2] : maxs[2]; } // // general sweeping through world // CM_RecursiveHullCheck (headnode, 0, 1, start, end); if (trace_trace.fraction == 1) { VectorCopy (end, trace_trace.endpos); } else { for (i=0 ; i<3 ; i++) trace_trace.endpos[i] = start[i] + trace_trace.fraction * (end[i] - start[i]); } return trace_trace; } /* ================== CM_TransformedBoxTrace Handles offseting and rotation of the end points for moving and rotating entities ================== */ #ifdef _WIN32 #pragma optimize( "", off ) #endif trace_t CM_TransformedBoxTrace (vec3_t start, vec3_t end, vec3_t mins, vec3_t maxs, int headnode, int brushmask, vec3_t origin, vec3_t angles) { trace_t trace; vec3_t start_l, end_l; vec3_t a; vec3_t forward, right, up; vec3_t temp; qboolean rotated; // subtract origin offset VectorSubtract (start, origin, start_l); VectorSubtract (end, origin, end_l); // rotate start and end into the models frame of reference if (angles[0] || angles[1] || angles[2] ) rotated = true; else rotated = false; if (rotated) { AngleVectors (angles, forward, right, up); VectorCopy (start_l, temp); start_l[0] = DotProduct (temp, forward); start_l[1] = -DotProduct (temp, right); start_l[2] = DotProduct (temp, up); VectorCopy (end_l, temp); end_l[0] = DotProduct (temp, forward); end_l[1] = -DotProduct (temp, right); end_l[2] = DotProduct (temp, up); } // sweep the box through the model trace = CM_BoxTrace (start_l, end_l, mins, maxs, headnode, brushmask); if (rotated && trace.fraction != 1.0) { // FIXME: figure out how to do this with existing angles VectorNegate (angles, a); AngleVectors (a, forward, right, up); VectorCopy (trace.plane.normal, temp); trace.plane.normal[0] = DotProduct (temp, forward); trace.plane.normal[1] = -DotProduct (temp, right); trace.plane.normal[2] = DotProduct (temp, up); } trace.endpos[0] = start[0] + trace.fraction * (end[0] - start[0]); trace.endpos[1] = start[1] + trace.fraction * (end[1] - start[1]); trace.endpos[2] = start[2] + trace.fraction * (end[2] - start[2]); return trace; } #ifdef _WIN32 #pragma optimize( "", on ) #endif /* =============================================================================== PVS / PHS =============================================================================== */ /* =================== CM_DecompressVis =================== */ /* void CM_DecompressVis (byte *in, byte *out) { int c; byte *out_p; int row; row = (numclusters+7)>>3; out_p = out; if (!in || !numvisibility) { // no vis info, so make all visible while (row) { *out_p++ = 0xff; row--; } return; } do { if (*in) { *out_p++ = *in++; continue; } c = in[1]; in += 2; if ((out_p - out) + c > row) { c = row - (out_p - out); Com_DPrintf ("warning: Vis decompression overrun\n"); } while (c) { *out_p++ = 0; c--; } } while (out_p - out < row); } byte pvsrow[MAX_MAP_LEAFS/8]; byte phsrow[MAX_MAP_LEAFS/8]; byte *CM_ClusterPVS (int cluster) { if (cluster == -1) memset (pvsrow, 0, (numclusters+7)>>3); else CM_DecompressVis (map_visibility + map_vis->bitofs[cluster][DVIS_PVS], pvsrow); return pvsrow; } byte *CM_ClusterPHS (int cluster) { if (cluster == -1) memset (phsrow, 0, (numclusters+7)>>3); else CM_DecompressVis (map_visibility + map_vis->bitofs[cluster][DVIS_PHS], phsrow); return phsrow; } */ /* =============================================================================== AREAPORTALS PENTA: Areaportals seem to have changed somewhat from quake2 this is based on the qfusion source who supports quake3 style areaportals =============================================================================== */ /* ==================== FloodAreaConnections ==================== */ void FloodAreaConnections (void) { int i, j; // area 0 is not used for (i=1 ; inumareas ; i++) { for ( j = 1; j < M->numareas; j++ ) { M->areas[i].numareaportals[j] = ( j == i ); } } } void CM_SetAreaPortalState (int area1, int area2, qboolean open) { if (area1 > M->numareas || area2 > M->numareas) { Con_Printf ("CM_SetAreaPortalState: area > M->numareas\n"); return; } if ( open ) { M->areas[area1].numareaportals[area2]++; M->areas[area2].numareaportals[area1]++; Con_Printf("Open portal between %i and %i\n", area1, area2); } else { M->areas[area1].numareaportals[area2]--; //shouln't really happen if (M->areas[area1].numareaportals[area2] < 0) M->areas[area1].numareaportals[area2] = 0; M->areas[area2].numareaportals[area1]--; //shouln't really happen if (M->areas[area2].numareaportals[area1] < 0) M->areas[area2].numareaportals[area1] = 0; Con_Printf("Close portal between %i and %i\n", area1, area2); } } qboolean CM_AreasConnected (int area1, int area2) { int i; /* if (cm_noAreas->value) return true; */ if (area1 > M->numareas || area2 > M->numareas) Sys_Error ("CM_AreasConnected: area > numareas"); if ( M->areas[area1].numareaportals[area2] ) return true; // area 0 is not used for (i=1 ; inumareas ; i++) { if ( M->areas[i].numareaportals[area1] && M->areas[i].numareaportals[area2] ) return true; } return false; } /* ================= CM_WriteAreaBits Writes a length byte followed by a bit vector of all the areas that area in the same flood as the area parameter This is used by the client refreshes to cull visibility ================= */ int CM_WriteAreaBits (byte *buffer, int area) { int i; int bytes; bytes = (M->numareas+7)>>3; /* if (cm_noAreas->value) { // for debugging, send everything memset (buffer, 255, bytes); } else */ { memset (buffer, 0, bytes); for (i=1 ; inumareas ; i++) { if (!area || CM_AreasConnected ( i, area ) || i == area) buffer[i>>3] |= 1<<(i&7); } } buffer[area>>3] |= 1<<(area&7); return bytes; } /* ================= CM_MergeAreaBits ================= */ void CM_MergeAreaBits (byte *buffer, int area) { int i; for (i=1 ; inumareas ; i++) { if ( CM_AreasConnected ( i, area ) || i == area) buffer[i>>3] |= 1<<(i&7); } } /* =================== CM_WritePortalState Writes the portal state to a savegame file =================== */ void CM_WritePortalState (FILE *f) { } /* =================== CM_ReadPortalState Reads the portal state from a savegame file and recalculates the area connections =================== */ void CM_ReadPortalState (FILE *f) { } /* ============= CM_HeadnodeVisible Returns true if any leaf under headnode has a cluster that is potentially visible ============= */ /* qboolean CM_HeadnodeVisible (int nodenum, byte *visbits) { int leafnum; int cluster; mnode_t *node; if (nodenum < 0) { leafnum = -1-nodenum; cluster = map_leafs[leafnum].cluster; if (cluster == -1) return false; if (visbits[cluster>>3] & (1<<(cluster&7))) return true; return false; } node = &map_nodes[nodenum]; if (CM_HeadnodeVisible(node->ichildren[0], visbits)) return true; return CM_HeadnodeVisible(node->ichildren[1], visbits); } */