world.c

quake1 dos源代码最新版本

/*
Copyright (C) 1996-1997 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 "quakedef.h"

/*

entities never clip against themselves, or their owner

line of sight checks trace->crosscontent, but bullets don't

*/


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;
	int			type;
	edict_t		*passedict;
} moveclip_t;


int SV_HullPointContents (hull_t *hull, int num, vec3_t p);

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

HULL BOXES

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


static	hull_t		box_hull;
static	dclipnode_t	box_clipnodes[6];
static	mplane_t	box_planes[6];

/*
===================
SV_InitBoxHull

Set up the planes and clipnodes so that the six floats of a bounding box
can just be stored out and get a proper hull_t structure.
===================
*/
void SV_InitBoxHull (void)
{
	int		i;
	int		side;

	box_hull.clipnodes = box_clipnodes;
	box_hull.planes = box_planes;
	box_hull.firstclipnode = 0;
	box_hull.lastclipnode = 5;

	for (i=0 ; i<6 ; i++)
	{
		box_clipnodes[i].planenum = i;

		side = i&1;

		box_clipnodes[i].children[side] = CONTENTS_EMPTY;
		if (i != 5)
			box_clipnodes[i].children[side^1] = i + 1;
		else
			box_clipnodes[i].children[side^1] = CONTENTS_SOLID;

		box_planes[i].type = i>>1;
		box_planes[i].normal[i>>1] = 1;
	}

}


/*
===================
SV_HullForBox

To keep everything totally uniform, bounding boxes are turned into small
BSP trees instead of being compared directly.
===================
*/
hull_t	*SV_HullForBox (vec3_t mins, vec3_t maxs)
{
	box_planes[0].dist = maxs[0];
	box_planes[1].dist = mins[0];
	box_planes[2].dist = maxs[1];
	box_planes[3].dist = mins[1];
	box_planes[4].dist = maxs[2];
	box_planes[5].dist = mins[2];

	return &box_hull;
}



/*
================
SV_HullForEntity

Returns a hull 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.
================
*/
hull_t *SV_HullForEntity (edict_t *ent, vec3_t mins, vec3_t maxs, vec3_t offset)
{
	model_t		*model;
	vec3_t		size;
	vec3_t		hullmins, hullmaxs;
	hull_t		*hull;

// decide which clipping hull to use, based on the size
	if (ent->v.solid == SOLID_BSP)
	{	// explicit hulls in the BSP model
		if (ent->v.movetype != MOVETYPE_PUSH)
			Sys_Error ("SOLID_BSP without MOVETYPE_PUSH");

		model = sv.models[ (int)ent->v.modelindex ];

		if (!model || model->type != mod_brush)
// 1999-10-07 MOVETYPE_PUSH fix by LordHavoc/Maddes  start
//			Sys_Error ("MOVETYPE_PUSH with a non bsp model");
			Sys_Error ("SOLID_BSP with a non bsp model");
// 1999-10-07 MOVETYPE_PUSH fix by LordHavoc/Maddes  end

		VectorSubtract (maxs, mins, size);
		if (size[0] < 3)
			hull = &model->hulls[0];
		else if (size[0] <= 32)
			hull = &model->hulls[1];
		else
			hull = &model->hulls[2];

// calculate an offset value to center the origin
		VectorSubtract (hull->clip_mins, mins, offset);
		VectorAdd (offset, ent->v.origin, offset);
	}
	else
	{	// create a temp hull from bounding box sizes

		VectorSubtract (ent->v.mins, maxs, hullmins);
		VectorSubtract (ent->v.maxs, mins, hullmaxs);
		hull = SV_HullForBox (hullmins, hullmaxs);

		VectorCopy (ent->v.origin, offset);
	}


	return hull;
}

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

ENTITY AREA CHECKING

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

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

static	areanode_t	sv_areanodes[AREA_NODES];
static	int			sv_numareanodes;

/*
===============
SV_CreateAreaNode

===============
*/
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)
{
	SV_InitBoxHull ();

	memset (sv_areanodes, 0, sizeof(sv_areanodes));
	sv_numareanodes = 0;
	SV_CreateAreaNode (0, sv.worldmodel->mins, sv.worldmodel->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_TouchLinks
====================
*/
void SV_TouchLinks ( edict_t *ent, areanode_t *node )
{
	link_t		*l, *next;
	edict_t		*touch;
	int			old_self, old_other;

// touch linked edicts
	for (l = node->trigger_edicts.next ; l != &node->trigger_edicts ; l = next)
	{
		next = l->next;
		touch = EDICT_FROM_AREA(l);
		if (touch == ent)
			continue;
		if (!touch->v.touch || touch->v.solid != SOLID_TRIGGER)
			continue;
		if (ent->v.absmin[0] > touch->v.absmax[0]
		|| ent->v.absmin[1] > touch->v.absmax[1]
		|| ent->v.absmin[2] > touch->v.absmax[2]
		|| ent->v.absmax[0] < touch->v.absmin[0]
		|| ent->v.absmax[1] < touch->v.absmin[1]
		|| ent->v.absmax[2] < touch->v.absmin[2] )
			continue;
		old_self = pr_global_struct->self;
		old_other = pr_global_struct->other;

		pr_global_struct->self = EDICT_TO_PROG(touch);
		pr_global_struct->other = EDICT_TO_PROG(ent);
		pr_global_struct->time = sv.time;
		PR_ExecuteProgram (touch->v.touch);

		pr_global_struct->self = old_self;
		pr_global_struct->other = old_other;
	}

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

	if ( ent->v.absmax[node->axis] > node->dist )
		SV_TouchLinks ( ent, node->children[0] );
	if ( ent->v.absmin[node->axis] < node->dist )
		SV_TouchLinks ( ent, node->children[1] );
}


/*
===============
SV_FindTouchedLeafs

===============
*/
void SV_FindTouchedLeafs (edict_t *ent, mnode_t *node)
{
	mplane_t	*splitplane;
	mleaf_t		*leaf;
	int			sides;
	int			leafnum;

	if (node->contents == CONTENTS_SOLID)
		return;

// add an efrag if the node is a leaf

	if ( node->contents < 0)
	{
		if (ent->num_leafs == MAX_ENT_LEAFS)
			return;

		leaf = (mleaf_t *)node;
		leafnum = leaf - sv.worldmodel->leafs - 1;

		ent->leafnums[ent->num_leafs] = leafnum;
		ent->num_leafs++;
		return;
	}

// NODE_MIXED

	splitplane = node->plane;
	sides = BOX_ON_PLANE_SIDE(ent->v.absmin, ent->v.absmax, splitplane);

// recurse down the contacted sides
	if (sides & 1)
		SV_FindTouchedLeafs (ent, node->children[0]);

	if (sides & 2)
		SV_FindTouchedLeafs (ent, node->children[1]);
}

/*
===============
SV_LinkEdict

===============
*/
void SV_LinkEdict (edict_t *ent, qboolean touch_triggers)
{
	areanode_t	*node;

	if (ent->area.prev)
		SV_UnlinkEdict (ent);	// unlink from old position

	if (ent == sv.edicts)
		return;		// don't add the world

	if (ent->free)
		return;

// set the abs box

#ifdef QUAKE2
	if (ent->v.solid == SOLID_BSP &&
	(ent->v.angles[0] || ent->v.angles[1] || ent->v.angles[2]) )
	{	// expand for rotation
		float		max, v;
		int			i;

// 2001-12-17 Incorrect bounding box of rotating bmodels fix by LordHavoc  start
/*
		max = 0;
		for (i=0 ; i<3 ; i++)
		{
			v =fabs( ent->v.mins[i]);
			if (v > max)
				max = v;
			v =fabs( ent->v.maxs[i]);
			if (v > max)
				max = v;
		}
*/

		max = DotProduct(ent->v.mins, ent->v.mins);
		v = DotProduct(ent->v.maxs, ent->v.maxs);
		if (v > max)
		{
			max = v;
		}
		max = sqrt(max);
// 2001-12-17 Incorrect bounding box of rotating bmodels fix by LordHavoc  end

		for (i=0 ; i<3 ; i++)
		{
			ent->v.absmin[i] = ent->v.origin[i] - max;
			ent->v.absmax[i] = ent->v.origin[i] + max;
		}
	}
	else
#endif
	{
		VectorAdd (ent->v.origin, ent->v.mins, ent->v.absmin);
		VectorAdd (ent->v.origin, ent->v.maxs, ent->v.absmax);
	}

//
// to make items easier to pick up and allow them to be grabbed off
// of shelves, the abs sizes are expanded
//
	if ((int)ent->v.flags & FL_ITEM)
	{
		ent->v.absmin[0] -= 15;
		ent->v.absmin[1] -= 15;
		ent->v.absmax[0] += 15;
		ent->v.absmax[1] += 15;
	}
	else
	{	// because movement is clipped an epsilon away from an actual edge,
		// we must fully check even when bounding boxes don't quite touch
		ent->v.absmin[0] -= 1;
		ent->v.absmin[1] -= 1;
		ent->v.absmin[2] -= 1;
		ent->v.absmax[0] += 1;
		ent->v.absmax[1] += 1;
		ent->v.absmax[2] += 1;
	}

// link to PVS leafs
	ent->num_leafs = 0;
	if (ent->v.modelindex)
		SV_FindTouchedLeafs (ent, sv.worldmodel->nodes);

	if (ent->v.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->v.absmin[node->axis] > node->dist)
			node = node->children[0];
		else if (ent->v.absmax[node->axis] < node->dist)
			node = node->children[1];
		else
			break;		// crosses the node
	}

// link it in

	if (ent->v.solid == SOLID_TRIGGER)
		InsertLinkBefore (&ent->area, &node->trigger_edicts);
	else
		InsertLinkBefore (&ent->area, &node->solid_edicts);

// if touch_triggers, touch all entities at this node and decend for more
	if (touch_triggers)
		SV_TouchLinks ( ent, sv_areanodes );
}