com.threed.jpct
Class Portals

java.lang.Object
  com.threed.jpct.Portals

All Implemented Interfaces:

java.io.Serializable

public final class Portals

extends java.lang.Object

implements java.io.Serializable

Portals handles the sectors and portals used for portal rendering. Portal rendering is a visibility algorithm (mostly) for indoor scenes. The basic idea is to connect different sectors (defined by a sector-number) with portals (n-polygons). Portal rendering can speed up rendering significantly, because it reduces overdraw by a very large amount. To get the idea better, one may have a look at some of the more detailed papers about this topic out there. Portals is always part of the World object.

See Also:

World.getPortals(), Serialized Form

Field Summary

static int	PORTAL_NOTDEFINITE The portal is not definite (can be the case if more than one portal from a sector into other sectors is visible).
static int	SECTOR_UNDEFINED The sector is undefined (this is sector 0).

Method Summary

void	addPortalCoord(float x, float y, float z) Adds a new vertex to the portal.
void	addPortalCoord(SimpleVector vert) Adds a new vertex to the portal.
void	completePortal() Signals that all vertices have been added to the portal and that the attributes have been set.
void	setAABoundingBox(int sector, float minx, float miny, float minz, float maxx, float maxy, float maxz) Sets the axis-aligned bounding box for a sector.
void	setPortalAttributes(int from, int to) Sets the attributes of the portal.
void	startNewPortal() Starts a new portal definition.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

PORTAL_NOTDEFINITE

public static final int PORTAL_NOTDEFINITE

The portal is not definite (can be the case if more than one portal from a sector into other sectors is visible). I can't recall where this information is given to the application, so consider this as an internal thing :-)

See Also:

Constant Field Values

SECTOR_UNDEFINED

public static final int SECTOR_UNDEFINED

The sector is undefined (this is sector 0). Objects that belong to an undefined sector will be processed regardless from the sector/portal combination in the current scene.

See Also:

Constant Field Values

Method Detail

startNewPortal

public void startNewPortal()

Starts a new portal definition. This method should be called before adding portal coordinates to a portal. The normal procedure is like this:
Portals p=theWorld.getPortals(); p.startNewPortal();
p.addPortalCoord(......); <- add as many coordinates as this portal has
... p.setPortalAttributes(from, to);
p.completePortal();

addPortalCoord

public void addPortalCoord(SimpleVector vert)

Adds a new vertex to the portal. Portals don't have to be triangles. Vertices have to be added counter-clockwise, because portals are backface culled.

Parameters:

vert - the new portal vertex

addPortalCoord

public void addPortalCoord(float x,
                           float y,
                           float z)

Adds a new vertex to the portal. Portals don't have to be triangles. Vertices have to be added counter-clockwise, because portals are backface culled.

Parameters:

x - the x component of the new portal vertex

y - the y component of the new portal vertex

z - the z component of the new portal vertex

setPortalAttributes

public void setPortalAttributes(int from,
                                int to)

Sets the attributes of the portal. A portal always goes from one sector into another. To connect two sectors (A and B), two portals are needed (at least): One connects A with B, the other one connects B with A. Portals are backface culled.

Parameters:

from - the "from-sector"

to - the "to-sector"

completePortal

public void completePortal()

Signals that all vertices have been added to the portal and that the attributes have been set.

setAABoundingBox

public void setAABoundingBox(int sector,
                             float minx,
                             float miny,
                             float minz,
                             float maxx,
                             float maxy,
                             float maxz)

Sets the axis-aligned bounding box for a sector. Normally, calling this method is not required as this information is automatically derived from the main world when calling build() for the main world's object.

Parameters:

sector - the sector's number (anything greater than zero)

minx - the minimum x-value of the bounding box

miny - the minimum y-value of the bounding box

minz - the minimum z-value of the bounding box

maxx - the maximum x-value of the bounding box

maxy - the maximum y-value of the bounding box

maxz - the maximum z-value of the bounding box

See Also:

Object3D.build()