world.c

quake1 dos源代码最新版本

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

POINT TESTING IN HULLS

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

#if	!id386

/*
==================
SV_HullPointContents

==================
*/
int SV_HullPointContents (hull_t *hull, int num, vec3_t p)
{
	float		d;
	dclipnode_t	*node;
	mplane_t	*plane;

	while (num >= 0)
	{
		if (num < hull->firstclipnode || num > hull->lastclipnode)
			Sys_Error ("SV_HullPointContents: bad node number");

		node = hull->clipnodes + num;
		plane = hull->planes + node->planenum;

		if (plane->type < 3)
			d = p[plane->type] - plane->dist;
		else
			d = DotProduct (plane->normal, p) - plane->dist;
		if (d < 0)
			num = node->children[1];
		else
			num = node->children[0];
	}

	return num;
}

#endif	// !id386


/*
==================
SV_PointContents

==================
*/
int SV_PointContents (vec3_t p)
{
	int		cont;

	cont = SV_HullPointContents (&sv.worldmodel->hulls[0], 0, p);
	if (cont <= CONTENTS_CURRENT_0 && cont >= CONTENTS_CURRENT_DOWN)
		cont = CONTENTS_WATER;
	return cont;
}

int SV_TruePointContents (vec3_t p)
{
	return SV_HullPointContents (&sv.worldmodel->hulls[0], 0, p);
}

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

/*
============
SV_TestEntityPosition

This could be a lot more efficient...
============
*/
edict_t	*SV_TestEntityPosition (edict_t *ent)
{
	trace_t	trace;

	trace = SV_Move (ent->v.origin, ent->v.mins, ent->v.maxs, ent->v.origin, 0, ent);

	if (trace.startsolid)
		return sv.edicts;

	return NULL;
}


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

LINE TESTING IN HULLS

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

// 1/32 epsilon to keep floating point happy
#define	DIST_EPSILON	(0.03125)

/*
==================
SV_RecursiveHullCheck

==================
*/
qboolean SV_RecursiveHullCheck (hull_t *hull, int num, float p1f, float p2f, vec3_t p1, vec3_t p2, trace_t *trace)
{
	dclipnode_t	*node;
	mplane_t	*plane;
	float		t1, t2;
	float		frac;
	int			i;
	vec3_t		mid;
	int			side;
	float		midf;

// check for empty
	if (num < 0)
	{
		if (num != CONTENTS_SOLID)
		{
			trace->allsolid = false;
			if (num == CONTENTS_EMPTY)
				trace->inopen = true;
			else
				trace->inwater = true;
		}
		else
			trace->startsolid = true;
		return true;		// empty
	}

	if (num < hull->firstclipnode || num > hull->lastclipnode)
		Sys_Error ("SV_RecursiveHullCheck: bad node number");

//
// find the point distances
//
	node = hull->clipnodes + num;
	plane = hull->planes + node->planenum;

	if (plane->type < 3)
	{
		t1 = p1[plane->type] - plane->dist;
		t2 = p2[plane->type] - plane->dist;
	}
	else
	{
		t1 = DotProduct (plane->normal, p1) - plane->dist;
		t2 = DotProduct (plane->normal, p2) - plane->dist;
	}

#if 1
	if (t1 >= 0 && t2 >= 0)
		return SV_RecursiveHullCheck (hull, node->children[0], p1f, p2f, p1, p2, trace);
	if (t1 < 0 && t2 < 0)
		return SV_RecursiveHullCheck (hull, node->children[1], p1f, p2f, p1, p2, trace);
#else
	if ( (t1 >= DIST_EPSILON && t2 >= DIST_EPSILON) || (t2 > t1 && t1 >= 0) )
		return SV_RecursiveHullCheck (hull, node->children[0], p1f, p2f, p1, p2, trace);
	if ( (t1 <= -DIST_EPSILON && t2 <= -DIST_EPSILON) || (t2 < t1 && t1 <= 0) )
		return SV_RecursiveHullCheck (hull, node->children[1], p1f, p2f, p1, p2, trace);
#endif

// put the crosspoint DIST_EPSILON pixels on the near side
	if (t1 < 0)
		frac = (t1 + DIST_EPSILON)/(t1-t2);
	else
		frac = (t1 - DIST_EPSILON)/(t1-t2);
	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]);

	side = (t1 < 0);

// move up to the node
	if (!SV_RecursiveHullCheck (hull, node->children[side], p1f, midf, p1, mid, trace) )
		return false;

#ifdef PARANOID
	if (SV_HullPointContents (sv_hullmodel, mid, node->children[side])
	== CONTENTS_SOLID)
	{
		Con_Printf ("mid PointInHullSolid\n");
		return false;
	}
#endif

	if (SV_HullPointContents (hull, node->children[side^1], mid)
	!= CONTENTS_SOLID)
// go past the node
		return SV_RecursiveHullCheck (hull, node->children[side^1], midf, p2f, mid, p2, trace);

	if (trace->allsolid)
		return false;		// never got out of the solid area

//==================
// the other side of the node is solid, this is the impact point
//==================
	if (!side)
	{
		VectorCopy (plane->normal, trace->plane.normal);
		trace->plane.dist = plane->dist;
	}
	else
	{
		VectorSubtract (vec3_origin, plane->normal, trace->plane.normal);
		trace->plane.dist = -plane->dist;
	}

	while (SV_HullPointContents (hull, hull->firstclipnode, mid)
	== CONTENTS_SOLID)
	{ // shouldn't really happen, but does occasionally
		frac -= 0.1;
		if (frac < 0)
		{
			trace->fraction = midf;
			VectorCopy (mid, trace->endpos);
			Con_DPrintf ("backup past 0\n");
			return false;
		}
		midf = p1f + (p2f - p1f)*frac;
		for (i=0 ; i<3 ; i++)
			mid[i] = p1[i] + frac*(p2[i] - p1[i]);
	}

	trace->fraction = midf;
	VectorCopy (mid, trace->endpos);

	return false;
}


/*
==================
SV_ClipMoveToEntity

Handles selection or creation of a clipping hull, and offseting (and
eventually rotation) of the end points
==================
*/
trace_t SV_ClipMoveToEntity (edict_t *ent, vec3_t start, vec3_t mins, vec3_t maxs, vec3_t end)
{
	trace_t		trace;
	vec3_t		offset;
	vec3_t		start_l, end_l;
	hull_t		*hull;

// fill in a default trace
	memset (&trace, 0, sizeof(trace_t));
	trace.fraction = 1;
	trace.allsolid = true;
	VectorCopy (end, trace.endpos);

// get the clipping hull
	hull = SV_HullForEntity (ent, mins, maxs, offset);

	VectorSubtract (start, offset, start_l);
	VectorSubtract (end, offset, end_l);

#ifdef QUAKE2
	// rotate start and end into the models frame of reference
	if (ent->v.solid == SOLID_BSP &&
	(ent->v.angles[0] || ent->v.angles[1] || ent->v.angles[2]) )
	{
		vec3_t	a;
		vec3_t	forward, right, up;
		vec3_t	temp;

		AngleVectors (ent->v.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);
	}
#endif

// trace a line through the apropriate clipping hull
	SV_RecursiveHullCheck (hull, hull->firstclipnode, 0, 1, start_l, end_l, &trace);

#ifdef QUAKE2
	// rotate endpos back to world frame of reference
	if (ent->v.solid == SOLID_BSP &&
	(ent->v.angles[0] || ent->v.angles[1] || ent->v.angles[2]) )
	{
		vec3_t	a;
		vec3_t	forward, right, up;
		vec3_t	temp;

		if (trace.fraction != 1)
		{
			VectorSubtract (vec3_origin, ent->v.angles, a);
			AngleVectors (a, forward, right, up);

			VectorCopy (trace.endpos, temp);
			trace.endpos[0] = DotProduct (temp, forward);
			trace.endpos[1] = -DotProduct (temp, right);
			trace.endpos[2] = DotProduct (temp, 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);
		}
	}
#endif

// fix trace up by the offset
	if (trace.fraction != 1)
		VectorAdd (trace.endpos, offset, trace.endpos);

// did we clip the move?
	if (trace.fraction < 1 || trace.startsolid  )
		trace.ent = ent;

	return trace;
}

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

/*
====================
SV_ClipToLinks

Mins and maxs enclose the entire area swept by the move
====================
*/
void SV_ClipToLinks ( areanode_t *node, moveclip_t *clip )
{
	link_t		*l, *next;
	edict_t		*touch;
	trace_t		trace;

// touch linked edicts
	for (l = node->solid_edicts.next ; l != &node->solid_edicts ; l = next)
	{
		next = l->next;
		touch = EDICT_FROM_AREA(l);
		if (touch->v.solid == SOLID_NOT)
			continue;
		if (touch == clip->passedict)
			continue;
		if (touch->v.solid == SOLID_TRIGGER)
			Sys_Error ("Trigger in clipping list");

		if (clip->type == MOVE_NOMONSTERS && touch->v.solid != SOLID_BSP)
			continue;

		if (clip->boxmins[0] > touch->v.absmax[0]
		|| clip->boxmins[1] > touch->v.absmax[1]
		|| clip->boxmins[2] > touch->v.absmax[2]
		|| clip->boxmaxs[0] < touch->v.absmin[0]
		|| clip->boxmaxs[1] < touch->v.absmin[1]
		|| clip->boxmaxs[2] < touch->v.absmin[2] )
			continue;

		if (clip->passedict && clip->passedict->v.size[0] && !touch->v.size[0])
			continue;	// points never interact

	// might intersect, so do an exact clip
		if (clip->trace.allsolid)
			return;
		if (clip->passedict)
		{
		 	if (PROG_TO_EDICT(touch->v.owner) == clip->passedict)
				continue;	// don't clip against own missiles
			if (PROG_TO_EDICT(clip->passedict->v.owner) == touch)
				continue;	// don't clip against owner
		}

		if ((int)touch->v.flags & FL_MONSTER)
			trace = SV_ClipMoveToEntity (touch, clip->start, clip->mins2, clip->maxs2, clip->end);
		else
			trace = SV_ClipMoveToEntity (touch, clip->start, clip->mins, clip->maxs, clip->end);
		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;
	}

// recurse down both sides
	if (node->axis == -1)
		return;

	if ( clip->boxmaxs[node->axis] > node->dist )
		SV_ClipToLinks ( node->children[0], clip );
	if ( clip->boxmins[node->axis] < node->dist )
		SV_ClipToLinks ( node->children[1], clip );
}


/*
==================
SV_MoveBounds
==================
*/
void SV_MoveBounds (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_Move
==================
*/
trace_t SV_Move (vec3_t start, vec3_t mins, vec3_t maxs, vec3_t end, int type, edict_t *passedict)
{
	moveclip_t	clip;
	int			i;

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

// clip to world
	clip.trace = SV_ClipMoveToEntity ( sv.edicts, start, mins, maxs, end );

	clip.start = start;
	clip.end = end;
	clip.mins = mins;
	clip.maxs = maxs;
	clip.type = type;
	clip.passedict = passedict;

	if (type == MOVE_MISSILE)
	{
		for (i=0 ; i<3 ; i++)
		{
			clip.mins2[i] = -15;
			clip.maxs2[i] = 15;
		}
	}
	else
	{
		VectorCopy (mins, clip.mins2);
		VectorCopy (maxs, clip.maxs2);
	}

// create the bounding box of the entire move
	SV_MoveBounds ( start, clip.mins2, clip.maxs2, end, clip.boxmins, clip.boxmaxs );

// clip to entities
	SV_ClipToLinks ( sv_areanodes, &clip );

	return clip.trace;
}