portals.c

quakeIII源码这个不用我多说吧

		//nudge playerstart around if needed so clipping hulls allways
		//have a valid point
		if (!strcmp(cl, "info_player_start"))
		{
			for (x = -16; x <= 16; x += 16)
			{
				for (y = -16; y <= 16; y += 16)
				{
					origin[0] += x;
					origin[1] += y;
					if (PlaceOccupant(headnode, origin, &entities[i]))
					{
						inside = true;
						x = 999; //stop for this info_player_start
						break;
					} //end if
					origin[0] -= x;
					origin[1] -= y;
				} //end for
			} //end for
		} //end if
		else
		{
			if (PlaceOccupant(headnode, origin, &entities[i]))
			{
				inside = true;
			} //end if
		} //end else
	} //end for

	if (!inside)
	{
		Log_Print("WARNING: no entities inside\n");
	} //end if
	else if (tree->outside_node.occupied)
	{
		Log_Print("WARNING: entity reached from outside\n");
	} //end else if

	return (qboolean)(inside && !tree->outside_node.occupied);
} //end of the function FloodEntities

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

FILL OUTSIDE

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

int c_outside;
int c_inside;
int c_solid;

//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void FillOutside_r (node_t *node)
{
	if (node->planenum != PLANENUM_LEAF)
	{
		FillOutside_r (node->children[0]);
		FillOutside_r (node->children[1]);
		return;
	} //end if
	// anything not reachable by an entity
	// can be filled away (by setting solid contents)
	if (!node->occupied)
	{
		if (!(node->contents & CONTENTS_SOLID))
		{
			c_outside++;
			node->contents |= CONTENTS_SOLID;
		} //end if
		else
		{
			c_solid++;
		} //end else
	} //end if
	else
	{
		c_inside++;
	} //end else
} //end of the function FillOutside_r
//===========================================================================
// Fill all nodes that can't be reached by entities
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void FillOutside (node_t *headnode)
{
	c_outside = 0;
	c_inside = 0;
	c_solid = 0;
	Log_Print("------- FillOutside --------\n");
	FillOutside_r (headnode);
	Log_Print("%5i solid leaves\n", c_solid);
	Log_Print("%5i leaves filled\n", c_outside);
	Log_Print("%5i inside leaves\n", c_inside);
} //end of the function FillOutside

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

FLOOD AREAS

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

int		c_areas;

//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void FloodAreas_r (node_t *node)
{
	portal_t	*p;
	int			s;
	bspbrush_t	*b;
	entity_t	*e;

	if (node->contents == CONTENTS_AREAPORTAL)
	{
		// this node is part of an area portal
		b = node->brushlist;
		e = &entities[b->original->entitynum];

		// if the current area has allready touched this
		// portal, we are done
		if (e->portalareas[0] == c_areas || e->portalareas[1] == c_areas)
			return;

		// note the current area as bounding the portal
		if (e->portalareas[1])
		{
			Log_Print("WARNING: areaportal entity %i touches > 2 areas\n", b->original->entitynum);
			return;
		}
		if (e->portalareas[0])
			e->portalareas[1] = c_areas;
		else
			e->portalareas[0] = c_areas;

		return;
	} //end if

	if (node->area)
		return;		// allready got it
	node->area = c_areas;

	for (p=node->portals ; p ; p = p->next[s])
	{
		s = (p->nodes[1] == node);
#if 0
		if (p->nodes[!s]->occupied)
			continue;
#endif
		if (!Portal_EntityFlood (p, s))
			continue;

		FloodAreas_r (p->nodes[!s]);
	} //end for
} //end of the function FloodAreas_r
//===========================================================================
// Just decend the tree, and for each node that hasn't had an
// area set, flood fill out from there
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void FindAreas_r (node_t *node)
{
	if (node->planenum != PLANENUM_LEAF)
	{
		FindAreas_r (node->children[0]);
		FindAreas_r (node->children[1]);
		return;
	}

	if (node->area)
		return;		// allready got it

	if (node->contents & CONTENTS_SOLID)
		return;

	if (!node->occupied)
		return;			// not reachable by entities

	// area portals are allways only flooded into, never
	// out of
	if (node->contents == CONTENTS_AREAPORTAL)
		return;

	c_areas++;
	FloodAreas_r (node);
} //end of the function FindAreas_r
//===========================================================================
// Just decend the tree, and for each node that hasn't had an
// area set, flood fill out from there
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void SetAreaPortalAreas_r (node_t *node)
{
	bspbrush_t	*b;
	entity_t	*e;

	if (node->planenum != PLANENUM_LEAF)
	{
		SetAreaPortalAreas_r (node->children[0]);
		SetAreaPortalAreas_r (node->children[1]);
		return;
	} //end if

	if (node->contents == CONTENTS_AREAPORTAL)
	{
		if (node->area)
			return;		// allready set

		b = node->brushlist;
		e = &entities[b->original->entitynum];
		node->area = e->portalareas[0];
		if (!e->portalareas[1])
		{
			Log_Print("WARNING: areaportal entity %i doesn't touch two areas\n", b->original->entitynum);
			return;
		} //end if
	} //end if
} //end of the function SetAreaPortalAreas_r
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
/*
void EmitAreaPortals(node_t *headnode)
{
	int				i, j;
	entity_t		*e;
	dareaportal_t	*dp;

	if (c_areas > MAX_MAP_AREAS)
		Error ("MAX_MAP_AREAS");
	numareas = c_areas+1;
	numareaportals = 1;		// leave 0 as an error

	for (i=1 ; i<=c_areas ; i++)
	{
		dareas[i].firstareaportal = numareaportals;
		for (j=0 ; j<num_entities ; j++)
		{
			e = &entities[j];
			if (!e->areaportalnum)
				continue;
			dp = &dareaportals[numareaportals];
			if (e->portalareas[0] == i)
			{
				dp->portalnum = e->areaportalnum;
				dp->otherarea = e->portalareas[1];
				numareaportals++;
			} //end if
			else if (e->portalareas[1] == i)
			{
				dp->portalnum = e->areaportalnum;
				dp->otherarea = e->portalareas[0];
				numareaportals++;
			} //end else if
		} //end for
		dareas[i].numareaportals = numareaportals - dareas[i].firstareaportal;
	} //end for

	Log_Print("%5i numareas\n", numareas);
	Log_Print("%5i numareaportals\n", numareaportals);
} //end of the function EmitAreaPortals
*/
//===========================================================================
// Mark each leaf with an area, bounded by CONTENTS_AREAPORTAL
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void FloodAreas (tree_t *tree)
{
	Log_Print("--- FloodAreas ---\n");
	FindAreas_r (tree->headnode);
	SetAreaPortalAreas_r (tree->headnode);
	Log_Print("%5i areas\n", c_areas);
} //end of the function FloodAreas
//===========================================================================
// Finds a brush side to use for texturing the given portal
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void FindPortalSide (portal_t *p)
{
	int			viscontents;
	bspbrush_t	*bb;
	mapbrush_t	*brush;
	node_t		*n;
	int			i,j;
	int			planenum;
	side_t		*side, *bestside;
	float		dot, bestdot;
	plane_t		*p1, *p2;

	// decide which content change is strongest
	// solid > lava > water, etc
	viscontents = VisibleContents (p->nodes[0]->contents ^ p->nodes[1]->contents);
	if (!viscontents)
		return;

	planenum = p->onnode->planenum;
	bestside = NULL;
	bestdot = 0;

	for (j=0 ; j<2 ; j++)
	{
		n = p->nodes[j];
		p1 = &mapplanes[p->onnode->planenum];
		for (bb=n->brushlist ; bb ; bb=bb->next)
		{
			brush = bb->original;
			if ( !(brush->contents & viscontents) )
				continue;
			for (i=0 ; i<brush->numsides ; i++)
			{
				side = &brush->original_sides[i];
				if (side->flags & SFL_BEVEL)
					continue;
				if (side->texinfo == TEXINFO_NODE)
					continue;		// non-visible
				if ((side->planenum&~1) == planenum)
				{	// exact match
					bestside = &brush->original_sides[i];
					goto gotit;
				} //end if
				// see how close the match is
				p2 = &mapplanes[side->planenum&~1];
				dot = DotProduct (p1->normal, p2->normal);
				if (dot > bestdot)
				{
					bestdot = dot;
					bestside = side;
				} //end if
			} //end for
		} //end for
	} //end for

gotit:
	if (!bestside)
		Log_Print("WARNING: side not found for portal\n");

	p->sidefound = true;
	p->side = bestside;
} //end of the function FindPortalSide
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void MarkVisibleSides_r (node_t *node)
{
	portal_t *p;
	int s;

	if (node->planenum != PLANENUM_LEAF)
	{
		MarkVisibleSides_r (node->children[0]);
		MarkVisibleSides_r (node->children[1]);
		return;
	} //end if

	// empty leaves are never boundary leaves
	if (!node->contents) return;

	// see if there is a visible face
	for (p=node->portals ; p ; p = p->next[!s])
	{
		s = (p->nodes[0] == node);
		if (!p->onnode)
			continue;		// edge of world
		if (!p->sidefound)
			FindPortalSide (p);
		if (p->side)
			p->side->flags |= SFL_VISIBLE;
	} //end for
} //end of the function MarkVisibleSides_r
//===========================================================================
//
// Parameter:				-
// Returns:					-
// Changes Globals:		-
//===========================================================================
void MarkVisibleSides(tree_t *tree, int startbrush, int endbrush)
{
	int		i, j;
	mapbrush_t	*mb;
	int		numsides;

	Log_Print("--- MarkVisibleSides ---\n");

	// clear all the visible flags
	for (i=startbrush ; i<endbrush ; i++)
	{
		mb = &mapbrushes[i];

		numsides = mb->numsides;
		for (j=0 ; j<numsides ; j++)
			mb->original_sides[j].flags &= ~SFL_VISIBLE;
	}

	// set visible flags on the sides that are used by portals
	MarkVisibleSides_r (tree->headnode);
} //end of the function MarkVisibleSides