sv_world.c

quakeIII源码这个不用我多说吧

			break;		// crosses the node
	}
	
	// link it in
	ent->worldSector = node;
	ent->nextEntityInWorldSector = node->entities;
	node->entities = ent;

	gEnt->r.linked = qtrue;
}

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

AREA QUERY

Fills in a list of all entities who's absmin / absmax intersects the given
bounds.  This does NOT mean that they actually touch in the case of bmodels.
============================================================================
*/

typedef struct {
	const float	*mins;
	const float	*maxs;
	int			*list;
	int			count, maxcount;
} areaParms_t;


/*
====================
SV_AreaEntities_r

====================
*/
void SV_AreaEntities_r( worldSector_t *node, areaParms_t *ap ) {
	svEntity_t	*check, *next;
	sharedEntity_t *gcheck;
	int			count;

	count = 0;

	for ( check = node->entities  ; check ; check = next ) {
		next = check->nextEntityInWorldSector;

		gcheck = SV_GEntityForSvEntity( check );

		if ( gcheck->r.absmin[0] > ap->maxs[0]
		|| gcheck->r.absmin[1] > ap->maxs[1]
		|| gcheck->r.absmin[2] > ap->maxs[2]
		|| gcheck->r.absmax[0] < ap->mins[0]
		|| gcheck->r.absmax[1] < ap->mins[1]
		|| gcheck->r.absmax[2] < ap->mins[2]) {
			continue;
		}

		if ( ap->count == ap->maxcount ) {
			Com_Printf ("SV_AreaEntities: MAXCOUNT\n");
			return;
		}

		ap->list[ap->count] = check - sv.svEntities;
		ap->count++;
	}
	
	if (node->axis == -1) {
		return;		// terminal node
	}

	// recurse down both sides
	if ( ap->maxs[node->axis] > node->dist ) {
		SV_AreaEntities_r ( node->children[0], ap );
	}
	if ( ap->mins[node->axis] < node->dist ) {
		SV_AreaEntities_r ( node->children[1], ap );
	}
}

/*
================
SV_AreaEntities
================
*/
int SV_AreaEntities( const vec3_t mins, const vec3_t maxs, int *entityList, int maxcount ) {
	areaParms_t		ap;

	ap.mins = mins;
	ap.maxs = maxs;
	ap.list = entityList;
	ap.count = 0;
	ap.maxcount = maxcount;

	SV_AreaEntities_r( sv_worldSectors, &ap );

	return ap.count;
}



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


typedef struct {
	vec3_t		boxmins, boxmaxs;// enclose the test object along entire move
	const float	*mins;
	const float *maxs;	// size of the moving object
	const float	*start;
	vec3_t		end;
	trace_t		trace;
	int			passEntityNum;
	int			contentmask;
	int			capsule;
} moveclip_t;


/*
====================
SV_ClipToEntity

====================
*/
void SV_ClipToEntity( trace_t *trace, const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end, int entityNum, int contentmask, int capsule ) {
	sharedEntity_t	*touch;
	clipHandle_t	clipHandle;
	float			*origin, *angles;

	touch = SV_GentityNum( entityNum );

	Com_Memset(trace, 0, sizeof(trace_t));

	// if it doesn't have any brushes of a type we
	// are looking for, ignore it
	if ( ! ( contentmask & touch->r.contents ) ) {
		trace->fraction = 1.0;
		return;
	}

	// might intersect, so do an exact clip
	clipHandle = SV_ClipHandleForEntity (touch);

	origin = touch->r.currentOrigin;
	angles = touch->r.currentAngles;

	if ( !touch->r.bmodel ) {
		angles = vec3_origin;	// boxes don't rotate
	}

	CM_TransformedBoxTrace ( trace, (float *)start, (float *)end,
		(float *)mins, (float *)maxs, clipHandle,  contentmask,
		origin, angles, capsule);

	if ( trace->fraction < 1 ) {
		trace->entityNum = touch->s.number;
	}
}


/*
====================
SV_ClipMoveToEntities

====================
*/
void SV_ClipMoveToEntities( moveclip_t *clip ) {
	int			i, num;
	int			touchlist[MAX_GENTITIES];
	sharedEntity_t *touch;
	int			passOwnerNum;
	trace_t		trace;
	clipHandle_t	clipHandle;
	float		*origin, *angles;

	num = SV_AreaEntities( clip->boxmins, clip->boxmaxs, touchlist, MAX_GENTITIES);

	if ( clip->passEntityNum != ENTITYNUM_NONE ) {
		passOwnerNum = ( SV_GentityNum( clip->passEntityNum ) )->r.ownerNum;
		if ( passOwnerNum == ENTITYNUM_NONE ) {
			passOwnerNum = -1;
		}
	} else {
		passOwnerNum = -1;
	}

	for ( i=0 ; i<num ; i++ ) {
		if ( clip->trace.allsolid ) {
			return;
		}
		touch = SV_GentityNum( touchlist[i] );

		// see if we should ignore this entity
		if ( clip->passEntityNum != ENTITYNUM_NONE ) {
			if ( touchlist[i] == clip->passEntityNum ) {
				continue;	// don't clip against the pass entity
			}
			if ( touch->r.ownerNum == clip->passEntityNum ) {
				continue;	// don't clip against own missiles
			}
			if ( touch->r.ownerNum == passOwnerNum ) {
				continue;	// don't clip against other missiles from our owner
			}
		}

		// if it doesn't have any brushes of a type we
		// are looking for, ignore it
		if ( ! ( clip->contentmask & touch->r.contents ) ) {
			continue;
		}

		// might intersect, so do an exact clip
		clipHandle = SV_ClipHandleForEntity (touch);

		origin = touch->r.currentOrigin;
		angles = touch->r.currentAngles;


		if ( !touch->r.bmodel ) {
			angles = vec3_origin;	// boxes don't rotate
		}

		CM_TransformedBoxTrace ( &trace, (float *)clip->start, (float *)clip->end,
			(float *)clip->mins, (float *)clip->maxs, clipHandle,  clip->contentmask,
			origin, angles, clip->capsule);

		if ( trace.allsolid ) {
			clip->trace.allsolid = qtrue;
			trace.entityNum = touch->s.number;
		} else if ( trace.startsolid ) {
			clip->trace.startsolid = qtrue;
			trace.entityNum = touch->s.number;
		}

		if ( trace.fraction < clip->trace.fraction ) {
			qboolean	oldStart;

			// make sure we keep a startsolid from a previous trace
			oldStart = clip->trace.startsolid;

			trace.entityNum = touch->s.number;
			clip->trace = trace;
			clip->trace.startsolid |= oldStart;
		}
	}
}


/*
==================
SV_Trace

Moves the given mins/maxs volume through the world from start to end.
passEntityNum and entities owned by passEntityNum are explicitly not checked.
==================
*/
void SV_Trace( trace_t *results, const vec3_t start, vec3_t mins, vec3_t maxs, const vec3_t end, int passEntityNum, int contentmask, int capsule ) {
	moveclip_t	clip;
	int			i;

	if ( !mins ) {
		mins = vec3_origin;
	}
	if ( !maxs ) {
		maxs = vec3_origin;
	}

	Com_Memset ( &clip, 0, sizeof ( moveclip_t ) );

	// clip to world
	CM_BoxTrace( &clip.trace, start, end, mins, maxs, 0, contentmask, capsule );
	clip.trace.entityNum = clip.trace.fraction != 1.0 ? ENTITYNUM_WORLD : ENTITYNUM_NONE;
	if ( clip.trace.fraction == 0 ) {
		*results = clip.trace;
		return;		// blocked immediately by the world
	}

	clip.contentmask = contentmask;
	clip.start = start;
//	VectorCopy( clip.trace.endpos, clip.end );
	VectorCopy( end, clip.end );
	clip.mins = mins;
	clip.maxs = maxs;
	clip.passEntityNum = passEntityNum;
	clip.capsule = capsule;

	// create the bounding box of the entire move
	// we can limit it to the part of the move not
	// already clipped off by the world, which can be
	// a significant savings for line of sight and shot traces
	for ( i=0 ; i<3 ; i++ ) {
		if ( end[i] > start[i] ) {
			clip.boxmins[i] = clip.start[i] + clip.mins[i] - 1;
			clip.boxmaxs[i] = clip.end[i] + clip.maxs[i] + 1;
		} else {
			clip.boxmins[i] = clip.end[i] + clip.mins[i] - 1;
			clip.boxmaxs[i] = clip.start[i] + clip.maxs[i] + 1;
		}
	}

	// clip to other solid entities
	SV_ClipMoveToEntities ( &clip );

	*results = clip.trace;
}



/*
=============
SV_PointContents
=============
*/
int SV_PointContents( const vec3_t p, int passEntityNum ) {
	int			touch[MAX_GENTITIES];
	sharedEntity_t *hit;
	int			i, num;
	int			contents, c2;
	clipHandle_t	clipHandle;
	float		*angles;

	// get base contents from world
	contents = CM_PointContents( p, 0 );

	// or in contents from all the other entities
	num = SV_AreaEntities( p, p, touch, MAX_GENTITIES );

	for ( i=0 ; i<num ; i++ ) {
		if ( touch[i] == passEntityNum ) {
			continue;
		}
		hit = SV_GentityNum( touch[i] );
		// might intersect, so do an exact clip
		clipHandle = SV_ClipHandleForEntity( hit );
		angles = hit->s.angles;
		if ( !hit->r.bmodel ) {
			angles = vec3_origin;	// boxes don't rotate
		}

		c2 = CM_TransformedPointContents (p, clipHandle, hit->s.origin, hit->s.angles);

		contents |= c2;
	}

	return contents;
}