Package de.extio.spacecraft.shared.world

Class WorldUtils

java.lang.Object

de.extio.spacecraft.shared.world.WorldUtils

public final class WorldUtils
extends Object

Library for geometric problems

Constructor Summary

Constructors

Constructor	Description
WorldUtils()

Method Summary

Modifier and Type	Method	Description
static int	calcEdgeRequirement(CoordI2 c0, CoordI2 c1)	Calculates edge required at c1 to block the path from c0 to c1.
static List<CoordI2>	evade(HasPositionAndDimension2 origin, double velOrigin, CoordD2 vOrigin, HasPositionAndDimension2 target, CoordD2 vTarget, CoordI2 oTarget, CoordI2 pInterception_)	Calculates waypoints to evade a collision between origin and target.
static CoordI2	getClosestPoint(CoordI2 origin, HasPositionAndDimension2 target)	Get's the closest point at area target from origin
static double	getDistance(CoordD2 v)	The Pythagorean theorem
static double	getDistance(CoordD2 c0, CoordD2 c1)	The Pythagorean theorem
static double	getDistance(CoordI2 v)	The Pythagorean theorem
static double	getDistance(CoordI2 c0, CoordI2 c1)	The Pythagorean theorem
static double	getDistance(HasPosition2 p0, HasPosition2 p1)	The Pythagorean theorem
static CoordD2	getPedal(CoordI2 a, CoordI2 b, CoordI2 c)	Calculates the pedal of altitude c of triangle A.B,C
static CoordD2	getPedalOnLineSegmentAB(CoordI2 a, CoordI2 b, CoordI2 c)	Get's the pedal of altitude c of triangle A.B,C or the closest point on line segment a,b
static CoordI2	getRandomPointInCircle(CoordI2 center, int radius)	Returns a random point in a circle
static CoordI2	getRandomPointInCircle(CoordI2 center, int radius, Random random)	Returns a point in a circle
static CoordI2	getRandomPointOnCircle(CoordI2 center, int radius)	Returns a random point on a circle
static CoordI2	getRandomPointOnCircle(CoordI2 center, int radius, Random random)	Returns a random point on a circle
static CoordI2	getReproduciblePointOnCircle(CoordI2 center, int radius, AtomicInteger counter)	Returns a reproducible point on a circle
static Edge2	getSector(CoordI2 point, HasPositionAndDimension2 source)	Returns the sector the point is located from source's view
static List<Area2>	getSides(HasPositionAndDimension2 obj)	x-----x | | | | x-----x
static double	getVectorAngle(CoordD2 v)	Calculate the direction of a vector
static double	getVectorAngle(CoordD2 v0, CoordD2 v1)	Calculate the angle between 2 vectors
static double	getVectorAngle(CoordI2 v)	Calculate the direction of a vector
static double	getVectorAngle(CoordI2 v0, CoordI2 v1)	Calculate the angle between 2 vectors
static double	getVectorDotProduct(CoordD2 v0, CoordD2 v1)	Calculate the dot product
static List<CoordI2>	getVertices(HasPositionAndDimension2 obj)	x-----x | | | | x-----x
static CoordI2	intercept(CoordI2 pOrigin_, double velOrigin, CoordI2 pTarget_, CoordD2 vTarget_)	Calculates the point of intersection to intercept target from origin with velocity velOrigin
static Area2	intersectAreas(HasPositionAndDimension2 a0, HasPositionAndDimension2 a1)	Intersects 2 areas
static RectI2	intersectRectangles(RectI2 r0, RectI2 r1)	Intersects 2 recangles
static boolean	intersects(CoordI2 position0, CoordI2 dimension0, CoordI2 position1, CoordI2 dimension1)	Checks whether 2 objects intersect
static boolean	intersects(HasPositionAndDimension2 obj0, HasPositionAndDimension2 obj1)	Checks whether 2 objects intersect
static boolean	isInBounds(CoordI2 coord, CoordI2 dimension)	Checks whether coord is within bounds (e.g.
static boolean	isInBounds(HasPosition2 hasPosition, CoordI2 dimension)	Checks whether coord is within bounds (e.g.
static Area2	pointsToArea(CoordI2... points)	Builds an aligned Area2 from arbitrary points
static CoordD2	rotateVector(CoordD2 v, double θ)	Rotates a vector
static int	strictSignum(double n)	Signum function that strictly returns -1 or 1.
static int	strictSignum(int n)	Signum function that strictly returns -1 or 1.
static CoordI2	translateEntityPosToWorldPos(AbstractCompositeEntity compositeEntity, CoordI2 entityPos)	Translates coordinate within composite entity to absolute world coordinate
static CoordI2	translateWorldPosToEntityPos(AbstractCompositeEntity compositeEntity, CoordI2 worldPos, boolean ignoreBounds)	Translates world coordinate to relative coordinate within composite entity

Methods inherited from class java.lang.Object

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

Constructor Detail

WorldUtils

public WorldUtils()

Method Detail

getDistance

public static double getDistance(CoordI2 v)

The Pythagorean theorem

Parameters:

v - Vector

Returns:

Length of vector v

getDistance

public static double getDistance(CoordD2 v)

The Pythagorean theorem

Parameters:

v - Vector

Returns:

Length of vector v

getDistance

public static double getDistance(HasPosition2 p0,
                                 HasPosition2 p1)

The Pythagorean theorem

Parameters:

p0 - Coordinate 0

p1 - Coordinate 1

Returns:

Distance

getDistance

public static double getDistance(CoordI2 c0,
                                 CoordI2 c1)

The Pythagorean theorem

Parameters:

c0 - Coordinate 0

c1 - Coordinate 1

Returns:

Distance

getDistance

public static double getDistance(CoordD2 c0,
                                 CoordD2 c1)

The Pythagorean theorem

Parameters:

c0 - Coordinate 0

c1 - Coordinate 1

Returns:

Distance

getVectorAngle

public static double getVectorAngle(CoordI2 v0,
                                    CoordI2 v1)

Calculate the angle between 2 vectors

Parameters:

v0 - Vector 0

v1 - Vector 1

Returns:

Angle (radians)

getVectorAngle

public static double getVectorAngle(CoordD2 v0,
                                    CoordD2 v1)

Calculate the angle between 2 vectors

Parameters:

v0 - Vector 0

v1 - Vector 1

Returns:

Angle (radians)

getVectorAngle

public static double getVectorAngle(CoordI2 v)

Calculate the direction of a vector

Parameters:

v0 - Vector 0

v1 - Vector 1

Returns:

Angle (radians)

getVectorAngle

public static double getVectorAngle(CoordD2 v)

Calculate the direction of a vector

Parameters:

v0 - Vector 0

v1 - Vector 1

Returns:

Angle (radians)

getVectorDotProduct

public static double getVectorDotProduct(CoordD2 v0,
                                         CoordD2 v1)

Calculate the dot product

Parameters:

v0 - Vector 0

v1 - Vector 1

Returns:

Dot product

rotateVector

public static CoordD2 rotateVector(CoordD2 v,
                                   double θ)

Rotates a vector

Returns:

Rotated vector

isInBounds

public static boolean isInBounds(HasPosition2 hasPosition,
                                 CoordI2 dimension)

Checks whether coord is within bounds (e.g. composite entity)

Parameters:

hasPosition -

Returns:

isInBounds

public static boolean isInBounds(CoordI2 coord,
                                 CoordI2 dimension)

Checks whether coord is within bounds (e.g. composite entity)

Parameters:

coord -

Returns:

strictSignum

public static int strictSignum(int n)

Signum function that strictly returns -1 or 1.

Parameters:

n -

Returns:

Mathematical signum function that returns -1 if n is negative and 1 if n is positive (including 0)

strictSignum

public static int strictSignum(double n)

Signum function that strictly returns -1 or 1.

Parameters:

n -

Returns:

Mathematical signum function that returns -1 if n is negative and 1 if n is positive (including 0)

intersectRectangles

public static RectI2 intersectRectangles(RectI2 r0,
                                         RectI2 r1)

Intersects 2 recangles

Parameters:

r0 - Rectangle 0

r1 - Rectangle 1

Returns:

The intersected area if r0 and r1 overlap, else null

intersectAreas

public static Area2 intersectAreas(HasPositionAndDimension2 a0,
                                   HasPositionAndDimension2 a1)

Intersects 2 areas

Parameters:

r0 - Area 0

r1 - Area 1

Returns:

The intersected area if r0 and r1 overlap, else null

intersects

public static boolean intersects(HasPositionAndDimension2 obj0,
                                 HasPositionAndDimension2 obj1)

Checks whether 2 objects intersect

Parameters:

obj0 - HasPositionAndDimension2 object 0

obj1 - HasPositionAndDimension2 object 1

Returns:

true / false whether obj0 intersects with obj1

intersects

public static boolean intersects(CoordI2 position0,
                                 CoordI2 dimension0,
                                 CoordI2 position1,
                                 CoordI2 dimension1)

Checks whether 2 objects intersect

Parameters:

position0 - position of object 0

dimension0 - dimension of object 0

position1 - position of object 1

dimension1 - dimension of object 1

Returns:

true / false whether obj0 intersects with obj1

translateWorldPosToEntityPos

public static CoordI2 translateWorldPosToEntityPos(AbstractCompositeEntity compositeEntity,
                                                   CoordI2 worldPos,
                                                   boolean ignoreBounds)

Translates world coordinate to relative coordinate within composite entity

Parameters:

compositeEntity -

worldPos -

Returns:

Relative entity coordinate, null if coordinate is outside bounds of the entity

translateEntityPosToWorldPos

public static CoordI2 translateEntityPosToWorldPos(AbstractCompositeEntity compositeEntity,
                                                   CoordI2 entityPos)

Translates coordinate within composite entity to absolute world coordinate

Parameters:

compositeEntity -

entityPos -

Returns:

Coordinate of entityPos in the world

pointsToArea

public static Area2 pointsToArea(CoordI2... points)

Builds an aligned Area2 from arbitrary points

Returns:

intercept

public static CoordI2 intercept(CoordI2 pOrigin_,
                                double velOrigin,
                                CoordI2 pTarget_,
                                CoordD2 vTarget_)

Calculates the point of intersection to intercept target from origin with velocity velOrigin

Parameters:

pOrigin_ - Position of origin (e.g. ship that intercepts target)

velOrigin - Velocity of origin

pTarget_ - Position of target

vTarget_ - Velocity vector of target

Returns:

Point of interception or null if interception is not possible

getSector

public static Edge2 getSector(CoordI2 point,
                              HasPositionAndDimension2 source)

Returns the sector the point is located from source's view

Parameters:

point -

source -

Returns:

Sector (Edge2)

getPedal

public static CoordD2 getPedal(CoordI2 a,
                               CoordI2 b,
                               CoordI2 c)

Calculates the pedal of altitude c of triangle A.B,C

Parameters:

a - Point A

b - Point B

c - Point C

Returns:

Pedal of altitude c

getPedalOnLineSegmentAB

public static CoordD2 getPedalOnLineSegmentAB(CoordI2 a,
                                              CoordI2 b,
                                              CoordI2 c)

Get's the pedal of altitude c of triangle A.B,C or the closest point on line segment a,b

   a-----p2-------b   p1
         |         \  |
         |          \ |
         |           \|
         c2            c1
 

Returns null if there is no pedal.

getClosestPoint

public static CoordI2 getClosestPoint(CoordI2 origin,
                                      HasPositionAndDimension2 target)

Get's the closest point at area target from origin

                *-----*
      |     |
      |     x _______ origin
      |     |
      *-----*
 

Parameters:

origin -

target -

Returns:

evade

public static List<CoordI2> evade(HasPositionAndDimension2 origin,
                                  double velOrigin,
                                  CoordD2 vOrigin,
                                  HasPositionAndDimension2 target,
                                  CoordD2 vTarget,
                                  CoordI2 oTarget,
                                  CoordI2 pInterception_)

Calculates waypoints to evade a collision between origin and target.

Parameters:

pOrigin - Origin

velOrigin - Origin velocity

vOrigin - Origin velocity vector, origin course not necessarily the current velocity vector

pTarget - Target

vTarget - Target velocity vector

oTarget - Collision offset on target (entityPos)

pInterception - (Optional) Point of interception. Can be null, in this case it is calculated based on the velocity of source and the velocity vector of target.

Returns:

Waypoints for evasion or null if there is no collision

getVertices

public static List<CoordI2> getVertices(HasPositionAndDimension2 obj)

  
   x-----x
   |     |
   |     |
   x-----x
 

Returns the 4 vertices of a rectangle

Parameters:

obj - Rectangle

Returns:

4 vertices ordered clock-wise

getSides

public static List<Area2> getSides(HasPositionAndDimension2 obj)

  
   x-----x
   |     |
   |     |
   x-----x
 

Returns the 4 sides of a rectangle

Parameters:

obj - Rectangle

Returns:

4 sides ordered clock-wise

getRandomPointInCircle

public static CoordI2 getRandomPointInCircle(CoordI2 center,
                                             int radius)

Returns a random point in a circle

Parameters:

center - of the circle

radius - of the circle

Returns:

random point in the circle

getRandomPointInCircle

public static CoordI2 getRandomPointInCircle(CoordI2 center,
                                             int radius,
                                             Random random)

Returns a point in a circle

Parameters:

center - of the circle

radius - of the circle

random - rng

Returns:

random point in the circle

getRandomPointOnCircle

public static CoordI2 getRandomPointOnCircle(CoordI2 center,
                                             int radius)

Returns a random point on a circle

Parameters:

center - of the circle

radius - of the circle

Returns:

random point in the circle

getRandomPointOnCircle

public static CoordI2 getRandomPointOnCircle(CoordI2 center,
                                             int radius,
                                             Random random)

Returns a random point on a circle

Parameters:

center - of the circle

radius - of the circle

random - rng

Returns:

random point in the circle

getReproduciblePointOnCircle

public static CoordI2 getReproduciblePointOnCircle(CoordI2 center,
                                                   int radius,
                                                   AtomicInteger counter)

Returns a reproducible point on a circle

Parameters:

center - of the circle

radius - of the circle

counter - decides where the point is

Returns:

random point in the circle

calcEdgeRequirement

public static int calcEdgeRequirement(CoordI2 c0,
                                      CoordI2 c1)

Calculates edge required at c1 to block the path from c0 to c1. Swap both parameters to get edge required at c0 to block the path from c1 to c0.

c0==> |c1
c0| <==c1

Parameters:

c0 - Position

c1 - Target

Returns:

Edges that are required as bit mask