324 lines
12 KiB
C
324 lines
12 KiB
C
/*
|
|
// ----------------------------------------------------------------------------
|
|
//
|
|
//
|
|
// OpenSteer -- Steering Behaviors for Autonomous Characters
|
|
//
|
|
// Copyright (c) 2002-2005, Sony Computer Entertainment America
|
|
// Original author: Craig Reynolds <craig_reynolds@playstation.sony.com>
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person obtaining a
|
|
// copy of this software and associated documentation files (the "Software"),
|
|
// to deal in the Software without restriction, including without limitation
|
|
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
|
// and/or sell copies of the Software, and to permit persons to whom the
|
|
// Software is furnished to do so, subject to the following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be included in
|
|
// all copies or substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
|
// DEALINGS IN THE SOFTWARE.
|
|
//
|
|
// ----------------------------------------------------------------------------
|
|
*/
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* */
|
|
/* Locality Query (LQ) Facility */
|
|
/* */
|
|
/* ------------------------------------------------------------------ */
|
|
/*
|
|
|
|
This utility is a spatial database which stores objects each of
|
|
which is associated with a 3d point (a location in a 3d space).
|
|
The points serve as the "search key" for the associated object.
|
|
It is intended to efficiently answer "sphere inclusion" queries,
|
|
also known as range queries: basically questions like:
|
|
|
|
Which objects are within a radius R of the location L?
|
|
|
|
In this context, "efficiently" means significantly faster than the
|
|
naive, brute force O(n) testing of all known points. Additionally
|
|
it is assumed that the objects move along unpredictable paths, so
|
|
that extensive preprocessing (for example, constructing a Delaunay
|
|
triangulation of the point set) may not be practical.
|
|
|
|
The implementation is a "bin lattice": a 3d rectangular array of
|
|
brick-shaped (rectangular parallelepipeds) regions of space. Each
|
|
region is represented by a pointer to a (possibly empty) doubly-
|
|
linked list of objects. All of these sub-bricks are the same
|
|
size. All bricks are aligned with the global coordinate axes.
|
|
|
|
Terminology used here: the region of space associated with a bin
|
|
is called a sub-brick. The collection of all sub-bricks is called
|
|
the super-brick. The super-brick should be specified to surround
|
|
the region of space in which (almost) all the key-points will
|
|
exist. If key-points move outside the super-brick everything will
|
|
continue to work, but without the speed advantage provided by the
|
|
spatial subdivision. For more details about how to specify the
|
|
super-brick's position, size and subdivisions see lqCreateDatabase
|
|
below.
|
|
|
|
Overview of usage: an application using this facility would first
|
|
create a database with lqCreateDatabase. For each client object
|
|
the application wants to put in the database it creates a
|
|
lqClientProxy and initializes it with lqInitClientProxy. When a
|
|
client object moves, the application calls lqUpdateForNewLocation.
|
|
To perform a query lqMapOverAllObjectsInLocality is passed an
|
|
application-supplied call-back function to be applied to all
|
|
client objects in the locality. See lqCallBackFunction below for
|
|
more detail. The lqFindNearestNeighborWithinRadius function can
|
|
be used to find a single nearest neighbor using the database.
|
|
|
|
Note that "locality query" is also known as neighborhood query,
|
|
neighborhood search, near neighbor search, and range query. For
|
|
additional information on this and related topics see:
|
|
http://www.red3d.com/cwr/boids/ips.html
|
|
|
|
For some description and illustrations of this database in use,
|
|
see this paper: http://www.red3d.com/cwr/papers/2000/pip.html
|
|
|
|
*/
|
|
|
|
#ifndef _lq_h
|
|
#define _lq_h
|
|
|
|
#ifdef __cplusplus
|
|
extern "C"
|
|
{
|
|
#endif
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* */
|
|
/* Data types use by LQ */
|
|
/* */
|
|
/* ------------------------------------------------------------------ */
|
|
/* This structure represents the spatial database. Typically one of
|
|
these would be created (by a call to lqCreateDatabase) for a given
|
|
application. */
|
|
|
|
|
|
typedef struct lqInternalDB lqDB;
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* This structure is a proxy for (and contains a pointer to) a client
|
|
(application) object in the spatial database. One of these exists
|
|
for each client object. This might be included within the
|
|
structure of a client object, or could be allocated separately. */
|
|
|
|
|
|
typedef struct lqClientProxy
|
|
{
|
|
/* previous object in this bin, or NULL */
|
|
struct lqClientProxy* prev;
|
|
|
|
/* next object in this bin, or NULL */
|
|
struct lqClientProxy* next;
|
|
|
|
/* bin ID (pointer to pointer to bin contents list) */
|
|
struct lqClientProxy** bin;
|
|
|
|
/* pointer to client object */
|
|
void* object;
|
|
|
|
/* the object's location ("key point") used for spatial sorting */
|
|
float x;
|
|
float y;
|
|
float z;
|
|
} lqClientProxy;
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* */
|
|
/* Basic API */
|
|
/* */
|
|
/* ------------------------------------------------------------------ */
|
|
/* Allocate and initialize an LQ database, returns a pointer to it.
|
|
The application needs to call this before using the LQ facility.
|
|
The nine parameters define the properties of the "super-brick":
|
|
(1) origin: coordinates of one corner of the super-brick, its
|
|
minimum x, y and z extent.
|
|
(2) size: the width, height and depth of the super-brick.
|
|
(3) the number of subdivisions (sub-bricks) along each axis.
|
|
This routine also allocates the bin array, and initialize its
|
|
contents. */
|
|
|
|
|
|
lqDB* lqCreateDatabase (float originx, float originy, float originz,
|
|
float sizex, float sizey, float sizez,
|
|
int divx, int divy, int divz);
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* Deallocates the LQ database */
|
|
|
|
|
|
void lqDeleteDatabase (lqDB*);
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* The application needs to call this once on each lqClientProxy at
|
|
setup time to initialize its list pointers and associate the proxy
|
|
with its client object. */
|
|
|
|
|
|
void lqInitClientProxy (lqClientProxy* proxy, void* clientObject);
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* Call for each client object every time its location changes. For
|
|
example, in an animation application, this would be called each
|
|
frame for every moving object. */
|
|
|
|
|
|
void lqUpdateForNewLocation (lqDB* lq,
|
|
lqClientProxy* object,
|
|
float x, float y, float z);
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* Apply an application-specific function to all objects in a certain
|
|
locality. The locality is specified as a sphere with a given
|
|
center and radius. All objects whose location (key-point) is
|
|
within this sphere are identified and the function is applied to
|
|
them. The application-supplied function takes three arguments:
|
|
|
|
(1) a void* pointer to an lqClientProxy's "object".
|
|
(2) the square of the distance from the center of the search
|
|
locality sphere (x,y,z) to object's key-point.
|
|
(3) a void* pointer to the caller-supplied "client query state"
|
|
object -- typically NULL, but can be used to store state
|
|
between calls to the lqCallBackFunction.
|
|
|
|
This routine uses the LQ database to quickly reject any objects in
|
|
bins which do not overlap with the sphere of interest. Incremental
|
|
calculation of index values is used to efficiently traverse the
|
|
bins of interest. */
|
|
|
|
|
|
/* type for a pointer to a function used to map over client objects */
|
|
typedef void (* lqCallBackFunction) (void* clientObject,
|
|
float distanceSquared,
|
|
void* clientQueryState);
|
|
|
|
|
|
void lqMapOverAllObjectsInLocality (lqDB* lq,
|
|
float x, float y, float z,
|
|
float radius,
|
|
lqCallBackFunction func,
|
|
void* clientQueryState);
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* */
|
|
/* Other API */
|
|
/* */
|
|
/* ------------------------------------------------------------------ */
|
|
/* Search the database to find the object whose key-point is nearest
|
|
to a given location yet within a given radius. That is, it finds
|
|
the object (if any) within a given search sphere which is nearest
|
|
to the sphere's center. The ignoreObject argument can be used to
|
|
exclude an object from consideration (or it can be NULL). This is
|
|
useful when looking for the nearest neighbor of an object in the
|
|
database, since otherwise it would be its own nearest neighbor.
|
|
The function returns a void* pointer to the nearest object, or
|
|
NULL if none is found. */
|
|
|
|
|
|
void* lqFindNearestNeighborWithinRadius (lqDB* lq,
|
|
float x, float y, float z,
|
|
float radius,
|
|
void* ignoreObject);
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* Adds a given client object to a given bin, linking it into the bin
|
|
contents list. */
|
|
|
|
|
|
void lqAddToBin (lqClientProxy* object, lqClientProxy** bin);
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* Removes a given client object from its current bin, unlinking it
|
|
from the bin contents list. */
|
|
|
|
|
|
void lqRemoveFromBin (lqClientProxy* object);
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* Given an LQ database object and the nine basic parameters: fill in
|
|
the object's slots, allocate the bin array, and initialize its
|
|
contents. Normally the application does NOT call this directly, it
|
|
is called by lqCreateDatabase. */
|
|
|
|
|
|
void lqInitDatabase (lqDB* lq,
|
|
float originx, float originy, float originz,
|
|
float sizex, float sizey, float sizez,
|
|
int divx, int divy, int divz);
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* Find the bin ID for a location in space. The location is given in
|
|
terms of its XYZ coordinates. The bin ID is a pointer to a pointer
|
|
to the bin contents list. */
|
|
|
|
|
|
lqClientProxy** lqBinForLocation (lqDB* lq, float x, float y, float z);
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* Apply a user-supplied function to all objects in the database,
|
|
regardless of locality (cf lqMapOverAllObjectsInLocality) */
|
|
|
|
|
|
void lqMapOverAllObjects (lqDB* lq,
|
|
lqCallBackFunction func,
|
|
void* clientQueryState);
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* Removes (all proxies for) all objects from all bins */
|
|
|
|
|
|
void lqRemoveAllObjects (lqDB* lq);
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* Get statistics about bin populations: min, max and average of
|
|
non-empty bins. */
|
|
|
|
|
|
#ifndef NO_LQ_BIN_STATS
|
|
void lqGetBinPopulationStats (lqDB* lq,
|
|
int* min,
|
|
int* max,
|
|
float* average);
|
|
#endif /* NO_LQ_BIN_STATS */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
|
|
|
|
#ifndef NULL
|
|
#define NULL 0
|
|
#endif
|
|
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* _lq_h */
|