[WIP] full rewrite of obstacle avoidance

This commit is contained in:
Alexander Nozik 2023-04-30 21:20:10 +03:00
parent b06fc5c87a
commit 8bc1987acf
17 changed files with 1291 additions and 704 deletions

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@ -0,0 +1,49 @@
package space.kscience.kmath.geometry
import space.kscience.kmath.operations.DoubleField.pow
import kotlin.math.sign
public fun Euclidean2DSpace.circle(x: Number, y: Number, radius: Number): Circle2D =
Circle2D(vector(x, y), radius = radius.toDouble())
public fun Euclidean2DSpace.segment(begin: DoubleVector2D, end: DoubleVector2D): LineSegment2D =
LineSegment(begin, end)
public fun Euclidean2DSpace.segment(x1: Number, y1: Number, x2: Number, y2: Number): LineSegment2D =
LineSegment(vector(x1, y1), vector(x2, y2))
public fun Euclidean2DSpace.intersectsOrInside(circle1: Circle2D, circle2: Circle2D): Boolean {
val distance = norm(circle2.center - circle1.center)
return distance <= circle1.radius + circle2.radius
}
/**
* https://mathworld.wolfram.com/Circle-LineIntersection.html
*/
public fun Euclidean2DSpace.intersects(segment: LineSegment2D, circle: Circle2D): Boolean {
val begin = segment.begin
val end = segment.end
val d = begin.distanceTo(end)
val det = (begin.x - circle.center.x) * (end.y - circle.center.y) -
(end.x - circle.center.x) * (begin.y - circle.center.y)
val incidence = circle.radius.pow(2) * d.pow(2) - det.pow(2)
return incidence >= 0
}
public fun Euclidean2DSpace.intersects(circle: Circle2D, segment: LineSegment2D): Boolean =
intersects(segment, circle)
public fun Euclidean2DSpace.intersects(segment1: LineSegment2D, segment2: LineSegment2D): Boolean {
infix fun DoubleVector2D.cross(v2: DoubleVector2D): Double = x * v2.y - y * v2.x
infix fun DoubleVector2D.crossSign(v2: DoubleVector2D) = cross(v2).sign
return with(Euclidean2DSpace) {
(segment2.begin - segment1.begin) crossSign (segment2.end - segment1.begin) !=
(segment2.begin - segment1.end) crossSign (segment2.end - segment1.end) &&
(segment1.begin - segment2.begin) crossSign (segment1.end - segment2.begin) !=
(segment1.begin - segment2.end) crossSign (segment1.end - segment2.end)
}
}

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@ -0,0 +1,10 @@
package space.kscience.kmath.geometry
import space.kscience.kmath.misc.zipWithNextCircular
public fun Euclidean2DSpace.polygon(points: List<DoubleVector2D>): Polygon<Double> = object : Polygon<Double> {
override val points: List<Vector2D<Double>> get() = points
}
public fun Euclidean2DSpace.intersects(polygon: Polygon<Double>, segment: LineSegment2D): Boolean =
polygon.points.zipWithNextCircular { l, r -> segment(l, r) }.any { intersects(it, segment) }

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@ -74,6 +74,8 @@ public object DubinsPath {
override fun toString(): String = "${first}${second}${third}"
public val last: Direction get() = third
public companion object {
public val RLR: Type = Type(R, L, R)
public val LRL: Type = Type(L, R, L)

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@ -24,6 +24,11 @@ public interface DubinsPose2D : DoubleVector2D {
public val coordinates: DoubleVector2D
public val bearing: Angle
/**
* Reverse the direction of this pose to the opposite, keeping other parameters the same
*/
public fun reversed(): DubinsPose2D
public companion object {
public fun bearingToVector(bearing: Angle): Vector2D<Double> =
Euclidean2DSpace.vector(cos(bearing), sin(bearing))
@ -35,12 +40,15 @@ public interface DubinsPose2D : DoubleVector2D {
}
}
@Serializable
public class PhaseVector2D(
override val coordinates: DoubleVector2D,
public val velocity: DoubleVector2D,
) : DubinsPose2D, DoubleVector2D by coordinates {
override val bearing: Angle get() = atan2(velocity.x, velocity.y).radians
override fun reversed(): DubinsPose2D = with(Euclidean2DSpace) { PhaseVector2D(coordinates, -velocity) }
}
@Serializable
@ -50,7 +58,9 @@ private class DubinsPose2DImpl(
override val bearing: Angle,
) : DubinsPose2D, DoubleVector2D by coordinates {
override fun toString(): String = "DubinsPose2D(x=$x, y=$y, bearing=$bearing)"
override fun reversed(): DubinsPose2D = DubinsPose2DImpl(coordinates, bearing.plus(Angle.pi).normalized())
override fun toString(): String = "Pose2D(x=$x, y=$y, bearing=$bearing)"
}
public object DubinsPose2DSerializer : KSerializer<DubinsPose2D> {
@ -69,7 +79,8 @@ public object DubinsPose2DSerializer : KSerializer<DubinsPose2D> {
}
}
public fun DubinsPose2D(coordinate: DoubleVector2D, bearing: Angle): DubinsPose2D = DubinsPose2DImpl(coordinate, bearing)
public fun DubinsPose2D(coordinate: DoubleVector2D, bearing: Angle): DubinsPose2D =
DubinsPose2DImpl(coordinate, bearing)
public fun DubinsPose2D(point: DoubleVector2D, direction: DoubleVector2D): DubinsPose2D =
DubinsPose2D(point, DubinsPose2D.vectorToBearing(direction))

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@ -5,96 +5,109 @@
package space.kscience.trajectory
import space.kscience.kmath.geometry.Angle
import space.kscience.kmath.geometry.Circle2D
import space.kscience.kmath.geometry.LineSegment2D
import space.kscience.kmath.geometry.Polygon
import space.kscience.kmath.geometry.Euclidean2DSpace
import space.kscience.kmath.geometry.Vector2D
import space.kscience.kmath.misc.zipWithNextCircular
public interface Obstacle {
public val circles: List<Circle2D>
public val center: Vector2D<Double>
public fun intersects(segment: LineSegment2D): Boolean
public val circumvention: CompositeTrajectory2D
/**
* Check if obstacle has intersection with given [Trajectory2D]
*/
public fun intersects(trajectory: Trajectory2D): Boolean =
Euclidean2DSpace.trajectoryIntersects(circumvention, trajectory)
public fun intersects(circle: Circle2D): Boolean
public companion object {
public fun avoidObstacles(
start: DubinsPose2D,
finish: DubinsPose2D,
trajectoryRadius: Double,
vararg obstacles: Obstacle,
): List<CompositeTrajectory2D> {
val obstacleShells: List<ObstacleShell> = obstacles.map { polygon ->
ObstacleShell(polygon.circles)
}
return findAllPaths(start, trajectoryRadius, finish, trajectoryRadius, obstacleShells)
}
public fun avoidPolygons(
start: DubinsPose2D,
finish: DubinsPose2D,
trajectoryRadius: Double,
vararg obstacles: Polygon<Double>,
): List<CompositeTrajectory2D> {
val obstacleShells: List<ObstacleShell> = obstacles.map { polygon ->
ObstacleShell(polygon.points.map { Circle2D(it, trajectoryRadius) })
}
return findAllPaths(start, trajectoryRadius, finish, trajectoryRadius, obstacleShells)
}
public fun avoidObstacles(
start: DubinsPose2D,
finish: DubinsPose2D,
trajectoryRadius: Double,
obstacles: Collection<Obstacle>,
): List<CompositeTrajectory2D> {
val obstacleShells: List<ObstacleShell> = obstacles.map { polygon ->
ObstacleShell(polygon.circles)
}
return findAllPaths(start, trajectoryRadius, finish, trajectoryRadius, obstacleShells)
}
public fun avoidPolygons(
start: DubinsPose2D,
finish: DubinsPose2D,
trajectoryRadius: Double,
obstacles: Collection<Polygon<Double>>,
): List<CompositeTrajectory2D> {
val obstacleShells: List<ObstacleShell> = obstacles.map { polygon ->
ObstacleShell(polygon.points.map { Circle2D(it, trajectoryRadius) })
}
return findAllPaths(start, trajectoryRadius, finish, trajectoryRadius, obstacleShells)
}
}
}
public fun Obstacle.intersectsTrajectory(trajectory: Trajectory2D): Boolean = when (trajectory) {
is CircleTrajectory2D -> intersects(trajectory.circle)
is StraightTrajectory2D -> intersects(trajectory)
is CompositeTrajectory2D -> trajectory.segments.any { intersectsTrajectory(it) }
private class ObstacleImpl(override val circles: List<Circle2D>) : Obstacle {
override val center: Vector2D<Double> by lazy {
Euclidean2DSpace.vector(
circles.sumOf { it.center.x } / circles.size,
circles.sumOf { it.center.y } / circles.size
)
}
override val circumvention: CompositeTrajectory2D by lazy {
with(Euclidean2DSpace) {
/**
* A closed right-handed circuit minimal path circumvention of an obstacle.
* @return null if number of distinct circles in the obstacle is less than
*/
require(circles.isNotEmpty()) { "Can't create circumvention for an empty obstacle" }
if (circles.size == 1) {
// a circumvention consisting of a single circle, starting on top
val circle = circles.first()
val top = vector(circle.center.x + circle.radius, circle.center.y)
val startEnd = DubinsPose2D(
top,
Angle.piDiv2
)
return@lazy CompositeTrajectory2D(
CircleTrajectory2D(circle, startEnd, startEnd)
)
}
//TODO use convex hull
//distinct and sorted in right-handed direction
val circles = circles.distinct().sortedBy {
(it.center - center).bearing
}
val tangents = circles.zipWithNextCircular { a: Circle2D, b: Circle2D ->
tangentsBetweenCircles(a, b)[DubinsPath.Type.RSR]
?: error("Can't find right handed circumvention")
}
val trajectory: List<Trajectory2D> = buildList {
for (i in 0 until tangents.lastIndex) {
add(tangents[i])
add(CircleTrajectory2D(circles[i + 1], tangents[i].endPose, tangents[i + 1].beginPose))
}
add(tangents.last())
add(CircleTrajectory2D(circles[0], tangents.last().endPose, tangents.first().beginPose))
}
return@lazy CompositeTrajectory2D(trajectory)
}
}
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (other == null || this::class != other::class) return false
other as ObstacleImpl
return circles == other.circles
}
override fun hashCode(): Int {
return circles.hashCode()
}
override fun toString(): String {
return "Obstacle(circles=$circles)"
}
}
public fun Obstacle(vararg circles: Circle2D): Obstacle = ObstacleShell(listOf(*circles))
public fun Obstacle(vararg circles: Circle2D): Obstacle = ObstacleImpl(listOf(*circles))
public fun Obstacle(points: List<Vector2D<Double>>, radius: Double): Obstacle =
ObstacleShell(points.map { Circle2D(it, radius) })
//public fun Trajectory2D.intersects(
// polygon: Polygon<Double>,
// radius: Double,
//): Boolean {
// val obstacle = Obstacle(polygon.points.map { point -> Circle2D(point, radius) })
// return when (this) {
// is CircleTrajectory2D -> {
// val nearestCircle = obstacle.circles.minBy { it.center.distanceTo(circle.center) }
//
// }
// is StraightTrajectory2D -> obstacle.intersects(this)
// is CompositeTrajectory2D -> segments.any { it.intersects(polygon, radius) }
// }
//}
ObstacleImpl(points.map { Circle2D(it, radius) })

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@ -0,0 +1,389 @@
package space.kscience.trajectory
//
//
//private class LR<T>(val l: T, val r: T) {
// operator fun get(direction: Trajectory2D.Direction) = when (direction) {
// Trajectory2D.L -> l
// Trajectory2D.R -> r
// }
//}
//
//private class TangentPath(val tangents: List<ObstacleTangent>) {
// fun last() = tangents.last()
//}
//
//private fun TangentPath(vararg tangents: ObstacleTangent) = TangentPath(listOf(*tangents))
//
//private fun Circle2D.isInside(other: Circle2D): Boolean {
// return center.distanceTo(other.center) + radius <= other.radius
//}
//
//
//internal class ObstacleShell(
// nodes: List<Circle2D>,
//) : Obstacle {
// override val circles: List<Circle2D>
// override val center: Vector2D<Double>
// private val shell: List<LineSegment2D>
// private val shellDirection: Trajectory2D.Direction
//
// init {
// this.center = Euclidean2DSpace.vector(
// nodes.sumOf { it.center.x } / nodes.size,
// nodes.sumOf { it.center.y } / nodes.size
// )
//
//// this.circles = nodes.filter { node ->
//// //filter nodes inside other nodes
//// nodes.none{ node !== it && node.isInside(it) }
//// }
//
// this.circles = nodes.distinct()
//
// if (nodes.size < 2) {
// shell = emptyList()
// shellDirection = Trajectory2D.R
// } else {
//
// //ignore cases when one circle is inside another one
// val lslTangents = circles.zipWithNextCircular { a, b ->
// tangentsBetweenCircles(a, b)[DubinsPath.Type.LSL] ?: error("Intersecting circles")
// }
//
// val rsrTangents = circles.zipWithNextCircular { a, b ->
// tangentsBetweenCircles(a, b)[DubinsPath.Type.RSR] ?: error("Intersecting circles")
// }
//
//
// val lslToCenter = lslTangents.sumOf { it.begin.distanceTo(center) } +
// lslTangents.sumOf { it.end.distanceTo(center) }
// val rsrToCenter = rsrTangents.sumOf { it.begin.distanceTo(center) } +
// rsrTangents.sumOf { it.end.distanceTo(center) }
//
// if (rsrToCenter >= lslToCenter) {
// this.shell = rsrTangents
// this.shellDirection = Trajectory2D.R
// } else {
// this.shell = lslTangents
// this.shellDirection = Trajectory2D.L
// }
// }
// }
//
// constructor(obstacle: Obstacle) : this(obstacle.circles)
//
// /**
// * Check if segment has any intersections with this obstacle
// */
// override fun intersects(segment: LineSegment2D): Boolean = with(Euclidean2DSpace) {
// shell.any { tangent -> intersects(segment, tangent) }
// || circles.any { circle -> intersects(segment, circle) }
// }
//
// internal fun innerIntersects(segment: LineSegment2D): Boolean = with(Euclidean2DSpace) {
// intersects(polygon(circles.map { it.center }), segment)
// }
//
// override fun intersects(circle: Circle2D): Boolean = with(Euclidean2DSpace) {
// shell.any { tangent -> intersects(tangent, circle) }
// || circles.any { c2 -> intersectsOrInside(circle, c2) }
// }
//
// /**
// * Tangent to next obstacle node in given direction
// */
// fun nextTangent(circleIndex: Int, direction: Trajectory2D.Direction): ObstacleTangent {
// if (circleIndex == -1) error("Circle does not belong to this tangent")
//
// val nextCircleIndex = if (direction == this.shellDirection) {
// if (circleIndex == circles.lastIndex) 0 else circleIndex + 1
// } else {
// if (circleIndex == 0) circles.lastIndex else circleIndex - 1
// }
//
// return ObstacleTangent(
// LineSegment(
// shell[nextCircleIndex].end,
// shell[nextCircleIndex].begin
// ),
// ObstacleConnection(this, circleIndex, direction),
// ObstacleConnection(this, nextCircleIndex, direction),
// )
// }
//
// /**
// * All tangents in given direction
// */
// internal fun tangentsAlong(
// initialCircleIndex: Int,
// finalCircleIndex: Int,
// direction: Trajectory2D.Direction,
// ): List<ObstacleTangent> {
// return buildList {
// var currentIndex = initialCircleIndex
// do {
// val tangent = nextTangent(currentIndex, direction)
// add(tangent)
// currentIndex = tangent.endNode.nodeIndex
// } while (currentIndex != finalCircleIndex)
// }
// }
//
// override fun equals(other: Any?): Boolean {
// if (other == null || other !is ObstacleShell) return false
// return circles == other.circles
// }
//
// override fun hashCode(): Int {
// return circles.hashCode()
// }
//}
//
//internal fun ObstacleShell(vararg circles: Circle2D): ObstacleShell = ObstacleShell(listOf(*circles))
//
//
//private fun arcLength(
// circle: Circle2D,
// point1: DoubleVector2D,
// point2: DoubleVector2D,
// direction: Trajectory2D.Direction,
//): Double {
// val phi1 = atan2(point1.y - circle.center.y, point1.x - circle.center.x)
// val phi2 = atan2(point2.y - circle.center.y, point2.x - circle.center.x)
// var angle = 0.0
// when (direction) {
// Trajectory2D.L -> {
// angle = if (phi2 >= phi1) {
// phi2 - phi1
// } else {
// 2 * PI + phi2 - phi1
// }
// }
//
// Trajectory2D.R -> {
// angle = if (phi2 >= phi1) {
// 2 * PI - (phi2 - phi1)
// } else {
// -(phi2 - phi1)
// }
// }
// }
// return circle.radius * angle
//}
//
//private fun normalVectors(v: DoubleVector2D, r: Double): Pair<DoubleVector2D, DoubleVector2D> {
// return Pair(
// r * Euclidean2DSpace.vector(v.y / Euclidean2DSpace.norm(v), -v.x / Euclidean2DSpace.norm(v)),
// r * Euclidean2DSpace.vector(-v.y / Euclidean2DSpace.norm(v), v.x / Euclidean2DSpace.norm(v))
// )
//}
//
//
//private fun constructTangentCircles(
// point: DoubleVector2D,
// direction: DoubleVector2D,
// r: Double,
//): LR<Circle2D> {
// val center1 = point + normalVectors(direction, r).first
// val center2 = point + normalVectors(direction, r).second
// val p1 = center1 - point
// return if (atan2(p1.y, p1.x) - atan2(direction.y, direction.x) in listOf(PI / 2, -3 * PI / 2)) {
// LR(
// Circle2D(center1, r),
// Circle2D(center2, r)
// )
// } else {
// LR(
// Circle2D(center2, r),
// Circle2D(center1, r)
// )
// }
//}
//
//private fun sortedObstacles(
// currentObstacle: Obstacle,
// obstacles: List<Obstacle>,
//): List<Obstacle> {
// return obstacles.sortedBy { Euclidean2DSpace.norm(it.center - currentObstacle.center) }
//}
//
///**
// * Check if all proposed paths have ended at [finalObstacle]
// */
//private fun allFinished(
// paths: List<TangentPath>,
// finalObstacle: Obstacle,
//): Boolean = paths.all { it.last().endNode.obstacle === finalObstacle }
//
//private fun LineSegment2D.toTrajectory() = StraightTrajectory2D(begin, end)
//
//
//private fun TangentPath.toTrajectory(): CompositeTrajectory2D = CompositeTrajectory2D(
// buildList {
// tangents.zipWithNext().forEach { (left, right: ObstacleTangent) ->
// add(left.lineSegment.toTrajectory())
// add(
// CircleTrajectory2D.of(
// right.startCircle.center,
// left.lineSegment.end,
// right.lineSegment.begin,
// right.startDirection
// )
// )
// }
//
// add(tangents.last().lineSegment.toTrajectory())
// }
//)
//
//internal fun findAllPaths(
// start: DubinsPose2D,
// startingRadius: Double,
// finish: DubinsPose2D,
// finalRadius: Double,
// obstacles: List<ObstacleShell>,
//): List<CompositeTrajectory2D> {
// fun DubinsPose2D.direction() = Euclidean2DSpace.vector(cos(bearing), sin(bearing))
//
// // two circles for the initial point
// val initialCircles = constructTangentCircles(
// start,
// start.direction(),
// startingRadius
// )
//
// //two circles for the final point
// val finalCircles = constructTangentCircles(
// finish,
// finish.direction(),
// finalRadius
// )
//
// //all valid trajectories
// val trajectories = mutableListOf<CompositeTrajectory2D>()
//
// for (i in listOf(Trajectory2D.L, Trajectory2D.R)) {
// for (j in listOf(Trajectory2D.L, Trajectory2D.R)) {
// //Using obstacle to minimize code bloat
// val initialObstacle = ObstacleShell(initialCircles[i])
// val finalObstacle = ObstacleShell(finalCircles[j])
//
// var currentPaths: List<TangentPath> = listOf(
// TangentPath(
// //We need only the direction of the final segment from this
// ObstacleTangent(
// LineSegment(start, start),
// ObstacleConnection(initialObstacle, 0, i),
// ObstacleConnection(initialObstacle, 0, i),
// )
// )
// )
// while (!allFinished(currentPaths, finalObstacle)) {
// // paths after next obstacle iteration
// val newPaths = mutableListOf<TangentPath>()
// // for each path propagate it one obstacle further
// for (tangentPath: TangentPath in currentPaths) {
// val currentNode = tangentPath.last().endNode
// val currentDirection: Trajectory2D.Direction = tangentPath.last().endDirection
// val currentObstacle: ObstacleShell = ObstacleShell(tangentPath.last().endNode.obstacle)
//
// // If path is finished, ignore it
// // TODO avoid returning to ignored obstacle on the next cycle
// if (currentObstacle == finalObstacle) {
// newPaths.add(tangentPath)
// } else {
// val tangentToFinal: ObstacleTangent =
// outerTangents(currentObstacle, finalObstacle)[DubinsPath.Type(
// currentDirection,
// Trajectory2D.S,
// j
// )] ?: break
//
// // searching for the nearest obstacle that intersects with the direct path
// val nextObstacle = obstacles.filter { obstacle ->
// obstacle.intersects(tangentToFinal)
// }.minByOrNull { currentObstacle.center.distanceTo(it.center) } ?: finalObstacle
//
// //TODO add break check for end of path
//
// // All valid tangents from current obstacle to the next one
// val nextTangents: Collection<ObstacleTangent> = outerTangents(
// currentObstacle,
// nextObstacle
// ).filter { (key, tangent) ->
//// obstacles.none { obstacle ->
//// obstacle === currentObstacle
//// || obstacle === nextObstacle
//// || obstacle.innerIntersects(tangent)
//// } && // does not intersect other obstacles
// key.first == currentDirection && // initial direction is the same as end of previous segment direction
// (nextObstacle != finalObstacle || key.third == j) // if it is the last, it should be the same as the one we are searching for
// }.values
//
// for (tangent in nextTangents) {
// val tangentsAlong = if (tangent.startCircle === tangentPath.last().endCircle) {
// //if the previous segment last circle is the same as first circle of the next segment
//
// //If obstacle consists of single circle, do not walk around
// if (currentObstacle.circles.size < 2) {
// emptyList()
// } else {
// val lengthMaxPossible = arcLength(
// tangent.startCircle,
// tangentPath.last().lineSegment.end,
// currentObstacle.nextTangent(
// tangent.beginNode.nodeIndex,
// currentDirection
// ).lineSegment.begin,
// currentDirection
// )
//
// val lengthCalculated = arcLength(
// tangent.startCircle,
// tangentPath.last().lineSegment.end,
// tangent.lineSegment.begin,
// currentDirection
// )
// // ensure that path does not go inside the obstacle
// if (lengthCalculated > lengthMaxPossible) {
// currentObstacle.tangentsAlong(
// currentNode.nodeIndex,
// tangent.beginNode.nodeIndex,
// currentDirection,
// )
// } else {
// emptyList()
// }
// }
// } else {
// currentObstacle.tangentsAlong(
// currentNode.nodeIndex,
// tangent.beginNode.nodeIndex,
// currentDirection,
// )
// }
// newPaths.add(TangentPath(tangentPath.tangents + tangentsAlong + tangent))
// }
// }
// }
// currentPaths = newPaths
// }
//
// trajectories += currentPaths.map { tangentPath ->
//// val lastDirection: Trajectory2D.Direction = tangentPath.last().endDirection
// val end = Obstacle(finalCircles[j])
// TangentPath(
// tangentPath.tangents +
// ObstacleTangent(
// LineSegment(finish, finish),
// ObstacleConnection(end, 0, j),
// ObstacleConnection(end, 0, j)
// )
// )
// }.map { it.toTrajectory() }
// }
// }
// return trajectories
//}

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@ -0,0 +1,363 @@
package space.kscience.trajectory
import space.kscience.kmath.geometry.*
import space.kscience.kmath.geometry.Euclidean2DSpace.distanceTo
import kotlin.collections.component1
import kotlin.collections.component2
import kotlin.math.PI
import kotlin.math.atan2
public class Obstacles(public val obstacles: List<Obstacle>) {
private inner class ObstacleConnection(
val obstacleIndex: Int,
val nodeIndex: Int,
val direction: Trajectory2D.Direction,
) {
val obstacle: Obstacle get() = obstacles[obstacleIndex]
val circle: Circle2D get() = obstacle.circles[nodeIndex]
}
private inner class ObstacleTangent(
val tangentTrajectory: StraightTrajectory2D,
val from: ObstacleConnection?,
val to: ObstacleConnection?,
) {
/**
* If false this tangent intersects another obstacle
*/
val isValid by lazy {
obstacles.indices.none {
it != from?.obstacleIndex && it != to?.obstacleIndex && obstacles[it].intersects(tangentTrajectory)
}
}
}
/**
* All tangents between two obstacles
*
* In general generates 4 paths.
* TODO check intersections.
*/
private fun tangentsBetween(
firstIndex: Int,
secondIndex: Int,
): Map<DubinsPath.Type, ObstacleTangent> = with(Euclidean2DSpace) {
val first = obstacles[firstIndex]
val second = obstacles[secondIndex]
val firstPolygon = polygon(first.circles.map { it.center })
val secondPolygon = polygon(second.circles.map { it.center })
buildMap {
for (firstCircleIndex in first.circles.indices) {
val firstCircle = first.circles[firstCircleIndex]
for (secondCircleIndex in second.circles.indices) {
val secondCircle = second.circles[secondCircleIndex]
for ((pathType, segment) in tangentsBetweenCircles(
firstCircle,
secondCircle
)) {
if (!intersects(firstPolygon, segment) && !intersects(secondPolygon, segment)) {
put(
pathType,
ObstacleTangent(
segment,
ObstacleConnection(firstIndex, firstCircleIndex, pathType.first),
ObstacleConnection(secondIndex, secondCircleIndex, pathType.third)
)
)
}
}
}
}
}
}
private fun tangentsFromCircle(
circle: Circle2D,
direction: Trajectory2D.Direction,
obstacleIndex: Int,
): Map<DubinsPath.Type, ObstacleTangent> = with(Euclidean2DSpace) {
val obstacle = obstacles[obstacleIndex]
val polygon = polygon(obstacle.circles.map { it.center })
buildMap {
for (circleIndex in obstacle.circles.indices) {
val obstacleCircle = obstacle.circles[circleIndex]
for ((pathType, segment) in tangentsBetweenCircles(
circle,
obstacleCircle
)) {
if (pathType.first == direction && !intersects(polygon, segment)) {
put(
pathType,
ObstacleTangent(
segment,
null,
ObstacleConnection(obstacleIndex, circleIndex, pathType.third)
)
)
}
}
}
}
}
private fun tangentToCircle(
obstacleIndex: Int,
obstacleDirection: Trajectory2D.Direction,
circle: Circle2D,
direction: Trajectory2D.Direction,
): ObstacleTangent? = with(Euclidean2DSpace) {
val obstacle = obstacles[obstacleIndex]
val polygon = polygon(obstacle.circles.map { it.center })
for (circleIndex in obstacle.circles.indices) {
val obstacleCircle = obstacle.circles[circleIndex]
tangentsBetweenCircles(
obstacleCircle,
circle
).get(DubinsPath.Type(obstacleDirection, Trajectory2D.S, direction))?.takeIf {
!intersects(polygon, it)
}?.let {
return ObstacleTangent(
it,
ObstacleConnection(obstacleIndex, circleIndex, obstacleDirection),
null,
)
}
}
return null
}
private val tangentsCache = hashMapOf<Pair<Int, Int>, Map<DubinsPath.Type, ObstacleTangent>>()
private fun getAllTangents(i: Int, j: Int): Map<DubinsPath.Type, ObstacleTangent> =
tangentsCache.getOrPut(i to j) {
tangentsBetween(i, j)
}
/**
* Circumvention trajectory alongside obstacle. Replacing first and last arcs with appropriate cuts
*/
private fun trajectoryBetween(tangent1: ObstacleTangent, tangent2: ObstacleTangent): CompositeTrajectory2D {
require(tangent1.to != null)
require(tangent2.from != null)
require(tangent1.to.obstacleIndex == tangent2.from.obstacleIndex)
require(tangent1.to.direction == tangent2.from.direction)
val circumvention = tangent1.to.obstacle.circumvention(
tangent1.to.direction,
tangent1.to.nodeIndex,
tangent2.from.nodeIndex
).segments.toMutableList()
//cutting first and last arcs to accommodate connection points
val first = circumvention.first() as CircleTrajectory2D
val last = circumvention.last() as CircleTrajectory2D
circumvention[0] = CircleTrajectory2D(
first.circle,
tangent1.tangentTrajectory.endPose,
first.end
)
circumvention[circumvention.lastIndex] = CircleTrajectory2D(
last.circle,
last.begin,
tangent2.tangentTrajectory.beginPose
)
return CompositeTrajectory2D(circumvention)
}
private inner class TangentPath(val tangents: List<ObstacleTangent>) {
val isFinished get() = tangents.last().to == null
fun toTrajectory(): CompositeTrajectory2D = CompositeTrajectory2D(
buildList<Trajectory2D> {
add(tangents.first().tangentTrajectory)
tangents.zipWithNext().forEach { (l, r) ->
addAll(trajectoryBetween(l, r).segments)
add(r.tangentTrajectory)
}
}
)
}
public fun allTrajectoriesAvoiding(
startCircle: Circle2D,
startDirection: Trajectory2D.Direction,
endCircle: Circle2D,
endDirection: Trajectory2D.Direction,
): Collection<Trajectory2D> {
val directTangent: StraightTrajectory2D = tangentsBetweenCircles(startCircle, endCircle).get(
DubinsPath.Type(startDirection, Trajectory2D.S, endDirection)
) ?: return emptySet()
//fast return if no obstacles intersect direct path
if (obstacles.none { it.intersects(directTangent) }) return listOf(directTangent)
/**
* Continue current tangent to final point or to the next obstacle
*/
fun TangentPath.nextSteps(): Collection<TangentPath> {
val connection = tangents.last().to
require(connection != null)
//indices of obstacles that are not on previous path
val remainingObstacleIndices = obstacles.indices - tangents.mapNotNull { it.to?.obstacleIndex }
//a tangent to end point, null if tangent could not be constructed
val tangentToEnd: ObstacleTangent = tangentToCircle(
connection.obstacleIndex,
connection.direction,
endCircle,
endDirection
) ?: return emptySet()
if (remainingObstacleIndices.none { obstacles[it].intersects(tangentToEnd.tangentTrajectory) }) return setOf(
TangentPath(tangents + tangentToEnd)
)
// tangents to other obstacles
return remainingObstacleIndices.sortedWith(
compareByDescending<Int> { obstacles[it].intersects(tangentToEnd.tangentTrajectory) } //take intersecting obstacles
.thenBy { connection.circle.center.distanceTo(obstacles[it].center) } //then nearest
).firstNotNullOf { nextObstacleIndex ->
//all tangents from cache
getAllTangents(connection.obstacleIndex, nextObstacleIndex).filter {
//filtered by direction
it.key.first == connection.direction
}.values.takeIf { it.isNotEmpty() } // skip if empty
}.map {
TangentPath(tangents + it)
}
}
//find nearest obstacle that has valid tangents to
val tangentsToFirstObstacle: Collection<ObstacleTangent> = obstacles.indices.sortedWith(
compareByDescending<Int> { obstacles[it].intersects(directTangent) } //take intersecting obstacles
.thenBy { startCircle.center.distanceTo(obstacles[it].center) } //then nearest
).firstNotNullOf { obstacleIndex ->
tangentsFromCircle(startCircle, startDirection, obstacleIndex).values
.filter { it.isValid }.takeIf { it.isNotEmpty() }
}
var paths = tangentsToFirstObstacle.map { TangentPath(listOf(it)) }
while (!paths.all { it.isFinished }) {
paths = paths.flatMap { it.nextSteps() }
}
return paths.map { it.toTrajectory() }
}
public companion object {
private data class LR<T>(val l: T, val r: T) {
operator fun get(direction: Trajectory2D.Direction) = when (direction) {
Trajectory2D.L -> l
Trajectory2D.R -> r
}
}
private fun normalVectors(v: DoubleVector2D, r: Double): Pair<DoubleVector2D, DoubleVector2D> =
with(Euclidean2DSpace) {
Pair(
r * vector(v.y / norm(v), -v.x / norm(v)),
r * vector(-v.y / norm(v), v.x / norm(v))
)
}
private fun constructTangentCircles(
pose: DubinsPose2D,
r: Double,
): LR<Circle2D> = with(Euclidean2DSpace) {
val direction = DubinsPose2D.bearingToVector(pose.bearing)
//TODO optimize to use bearing
val center1 = pose + normalVectors(direction, r).first
val center2 = pose + normalVectors(direction, r).second
val p1 = center1 - pose
return if (atan2(p1.y, p1.x) - atan2(direction.y, direction.x) in listOf(PI / 2, -3 * PI / 2)) {
LR(
Circle2D(center1, r),
Circle2D(center2, r)
)
} else {
LR(
Circle2D(center2, r),
Circle2D(center1, r)
)
}
}
public fun avoidObstacles(
start: DubinsPose2D,
finish: DubinsPose2D,
startingRadius: Double,
obstacleList: List<Obstacle>,
finalRadius: Double = startingRadius,
): List<Trajectory2D> {
val obstacles = Obstacles(obstacleList)
val initialCircles = constructTangentCircles(
start,
startingRadius
)
//two circles for the final point
val finalCircles = constructTangentCircles(
finish,
finalRadius
)
val lr = listOf(Trajectory2D.L, Trajectory2D.R)
return buildList {
lr.forEach { beginDirection ->
lr.forEach { endDirection ->
addAll(
obstacles.allTrajectoriesAvoiding(
initialCircles[beginDirection],
beginDirection,
finalCircles[endDirection],
endDirection
)
)
}
}
}
}
public fun avoidObstacles(
start: DubinsPose2D,
finish: DubinsPose2D,
trajectoryRadius: Double,
vararg obstacles: Obstacle,
): List<Trajectory2D> = avoidObstacles(start, finish, trajectoryRadius, obstacles.toList())
public fun avoidPolygons(
start: DubinsPose2D,
finish: DubinsPose2D,
trajectoryRadius: Double,
vararg polygons: Polygon<Double>,
): List<Trajectory2D> {
val obstacles: List<Obstacle> = polygons.map { polygon ->
Obstacle(polygon.points, trajectoryRadius)
}
return avoidObstacles(start, finish, trajectoryRadius, obstacles)
}
public fun avoidPolygons(
start: DubinsPose2D,
finish: DubinsPose2D,
trajectoryRadius: Double,
polygons: Collection<Polygon<Double>>,
): List<Trajectory2D> {
val obstacles: List<Obstacle> = polygons.map { polygon ->
Obstacle(polygon.points, trajectoryRadius)
}
return avoidObstacles(start, finish, trajectoryRadius, obstacles)
}
}
}

View File

@ -11,16 +11,24 @@ import kotlinx.serialization.Serializable
import kotlinx.serialization.UseSerializers
import space.kscience.kmath.geometry.*
import space.kscience.kmath.geometry.Euclidean2DSpace.distanceTo
import space.kscience.kmath.geometry.Euclidean2DSpace.minus
import kotlin.math.atan2
@Serializable
public sealed interface Trajectory2D {
public val length: Double
public val beginPose: DubinsPose2D
public val endPose: DubinsPose2D
/**
* Produce a trajectory with reversed order of points
*/
public fun reversed(): Trajectory2D
public sealed interface Type
public sealed interface Direction: Type
public sealed interface Direction : Type
public object R : Direction {
override fun toString(): String = "R"
@ -35,6 +43,9 @@ public sealed interface Trajectory2D {
}
}
public val DoubleVector2D.bearing: Angle get() = (atan2(x, y).radians).normalized()
/**
* Straight path segment. The order of start and end defines the direction
*/
@ -47,49 +58,60 @@ public data class StraightTrajectory2D(
override val length: Double get() = begin.distanceTo(end)
public val bearing: Angle get() = (atan2(end.x - begin.x, end.y - begin.y).radians).normalized()
public val bearing: Angle get() = (end - begin).bearing
override val beginPose: DubinsPose2D get() = DubinsPose2D(begin, bearing)
override val endPose: DubinsPose2D get() = DubinsPose2D(end, bearing)
override fun reversed(): StraightTrajectory2D = StraightTrajectory2D(end, begin)
}
public fun StraightTrajectory2D(segment: LineSegment2D): StraightTrajectory2D =
StraightTrajectory2D(segment.begin, segment.end)
/**
* An arc segment
*/
@Serializable
@SerialName("arc")
public data class CircleTrajectory2D(
public data class CircleTrajectory2D (
public val circle: Circle2D,
public val start: DubinsPose2D,
public val begin: DubinsPose2D,
public val end: DubinsPose2D,
) : Trajectory2D {
override val beginPose: DubinsPose2D get() = begin
override val endPose: DubinsPose2D get() = end
/**
* Arc length in radians
*/
val arcLength: Angle
val arcAngle: Angle
get() = if (direction == Trajectory2D.L) {
start.bearing - end.bearing
begin.bearing - end.bearing
} else {
end.bearing - start.bearing
end.bearing - begin.bearing
}.normalized()
override val length: Double by lazy {
circle.radius * arcLength.radians
circle.radius * arcAngle.radians
}
public val direction: Trajectory2D.Direction by lazy {
if (start.y < circle.center.y) {
if (start.bearing > Angle.pi) Trajectory2D.R else Trajectory2D.L
} else if (start.y > circle.center.y) {
if (start.bearing < Angle.pi) Trajectory2D.R else Trajectory2D.L
when {
begin.y < circle.center.y -> if (begin.bearing > Angle.pi) Trajectory2D.R else Trajectory2D.L
begin.y > circle.center.y -> if (begin.bearing < Angle.pi) Trajectory2D.R else Trajectory2D.L
else -> if (begin.bearing == Angle.zero) {
if (begin.x < circle.center.x) Trajectory2D.R else Trajectory2D.L
} else {
if (start.bearing == Angle.zero) {
if (start.x < circle.center.x) Trajectory2D.R else Trajectory2D.L
} else {
if (start.x > circle.center.x) Trajectory2D.R else Trajectory2D.L
if (begin.x > circle.center.x) Trajectory2D.R else Trajectory2D.L
}
}
}
override fun reversed(): CircleTrajectory2D = CircleTrajectory2D(circle, end.reversed(), begin.reversed())
public companion object {
public fun of(
center: DoubleVector2D,
@ -124,8 +146,28 @@ public data class CircleTrajectory2D(
@SerialName("composite")
public class CompositeTrajectory2D(public val segments: List<Trajectory2D>) : Trajectory2D {
override val length: Double get() = segments.sumOf { it.length }
override val beginPose: DubinsPose2D get() = segments.first().beginPose
override val endPose: DubinsPose2D get() = segments.last().endPose
override fun reversed(): CompositeTrajectory2D = CompositeTrajectory2D(segments.map { it.reversed() }.reversed())
}
public fun CompositeTrajectory2D(vararg segments: Trajectory2D): CompositeTrajectory2D =
CompositeTrajectory2D(segments.toList())
public fun Euclidean2DSpace.trajectoryIntersects(a: Trajectory2D, b: Trajectory2D): Boolean = when (a) {
is CircleTrajectory2D -> when (b) {
is CircleTrajectory2D -> intersectsOrInside(a.circle, b.circle)
is StraightTrajectory2D -> intersects(a.circle, b)
is CompositeTrajectory2D -> b.segments.any { trajectoryIntersects(it, b) }
}
is StraightTrajectory2D -> when (b) {
is CircleTrajectory2D -> intersects(a, b.circle)
is StraightTrajectory2D -> intersects(a, b)
is CompositeTrajectory2D -> b.segments.any { trajectoryIntersects(it, b) }
}
is CompositeTrajectory2D -> a.segments.any { trajectoryIntersects(it, b) }
}

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@ -0,0 +1,120 @@
package space.kscience.trajectory
import space.kscience.kmath.geometry.Circle2D
import space.kscience.kmath.geometry.Euclidean2DSpace
import space.kscience.trajectory.DubinsPath.Type
import kotlin.math.*
/**
* Create inner and outer tangents between two circles.
* This method returns a map of segments using [DubinsPath] connection type notation.
*/
internal fun tangentsBetweenCircles(
first: Circle2D,
second: Circle2D,
): Map<Type, StraightTrajectory2D> = with(Euclidean2DSpace) {
// Distance between centers
val distanceBetweenCenters: Double = first.center.distanceTo(second.center)
// return empty map if one circle is inside another
val minRadius = min(first.radius, second.radius)
val maxRadius = max(first.radius, second.radius)
val listOfTangents = when {
// one circle inside another, no tangents
distanceBetweenCenters + minRadius <= maxRadius -> return emptyMap()
// circles intersect, only outer tangents
distanceBetweenCenters - minRadius <= maxRadius -> listOf(Type.RSR, Type.LSL)
// no intersections all tangents
else -> listOf(Type.RSR, Type.RSL, Type.LSR, Type.LSL)
}
val angle1 = atan2(second.center.x - first.center.x, second.center.y - first.center.y)
return listOfTangents.associateWith { route ->
val r1 = when (route.first) {
Trajectory2D.L -> -first.radius
Trajectory2D.R -> first.radius
}
val r2 = when (route.third) {
Trajectory2D.L -> -second.radius
Trajectory2D.R -> second.radius
}
val r = if (r1.sign == r2.sign) {
r1.absoluteValue - r2.absoluteValue
} else {
r1.absoluteValue + r2.absoluteValue
}
val l = sqrt(distanceBetweenCenters * distanceBetweenCenters - r * r)
val angle2 = if (r1.absoluteValue > r2.absoluteValue) {
angle1 + r1.sign * atan2(r.absoluteValue, l)
} else {
angle1 - r2.sign * atan2(r.absoluteValue, l)
}
val w = vector(-cos(angle2), sin(angle2))
StraightTrajectory2D(
first.center + w * r1,
second.center + w * r2
)
}
}
/**
* Create an obstacle circumvention in given [direction] starting (including) from obstacle node with given [fromIndex]
*/
public fun Obstacle.circumvention(direction: Trajectory2D.Direction, fromIndex: Int): CompositeTrajectory2D {
require(fromIndex in circles.indices) { "$fromIndex is not in ${circles.indices}" }
val startCircle = circles[fromIndex]
val segments = buildList {
val reserve = mutableListOf<Trajectory2D>()
val sourceSegments = when (direction) {
Trajectory2D.L -> circumvention.reversed().segments
Trajectory2D.R -> circumvention.segments
}
var i = 0
while ((sourceSegments[i] as? CircleTrajectory2D)?.circle !== startCircle) {
//put all segments before target circle on the reserve
reserve.add(sourceSegments[i])
i++
}
while (i < sourceSegments.size) {
// put required segments on result list
add(sourceSegments[i])
i++
}
//add remaining segments from reserve
addAll(reserve)
check(i == sourceSegments.size)
}
return CompositeTrajectory2D(segments)
}
/**
* Create an obstacle circumvention in given [direction] starting (including) from obstacle node with given [fromIndex]
* and ending (including) at obstacle node with given [toIndex]
*/
public fun Obstacle.circumvention(
direction: Trajectory2D.Direction,
fromIndex: Int,
toIndex: Int,
): CompositeTrajectory2D {
require(toIndex in circles.indices) { "$toIndex is not in ${circles.indices}" }
val toCircle = circles[toIndex]
val fullCircumvention = circumvention(direction, fromIndex).segments
return CompositeTrajectory2D(
buildList {
var i = 0
do {
val segment = fullCircumvention[i]
add(segment)
i++
} while ((segment as? CircleTrajectory2D)?.circle != toCircle)
}
)
}

View File

@ -1,536 +0,0 @@
package space.kscience.trajectory
import space.kscience.kmath.geometry.*
import space.kscience.kmath.geometry.Euclidean2DSpace.distanceTo
import space.kscience.kmath.geometry.Euclidean2DSpace.minus
import space.kscience.kmath.geometry.Euclidean2DSpace.plus
import space.kscience.kmath.geometry.Euclidean2DSpace.times
import space.kscience.kmath.misc.zipWithNextCircular
import space.kscience.kmath.operations.DoubleField.pow
import kotlin.math.*
internal data class ObstacleConnection(
val obstacle: Obstacle,
val nodeIndex: Int,
val direction: Trajectory2D.Direction,
) {
val circle get() = obstacle.circles[nodeIndex]
}
internal data class ObstacleTangent(
val lineSegment: LineSegment2D,
val beginNode: ObstacleConnection,
val endNode: ObstacleConnection,
) : LineSegment2D by lineSegment {
val startCircle get() = beginNode.circle
val startDirection get() = beginNode.direction
val endCircle get() = endNode.circle
val endDirection get() = endNode.direction
}
private class LR<T>(val l: T, val r: T) {
operator fun get(direction: Trajectory2D.Direction) = when (direction) {
Trajectory2D.L -> l
Trajectory2D.R -> r
}
}
private class TangentPath(val tangents: List<ObstacleTangent>) {
fun last() = tangents.last()
}
private fun TangentPath(vararg tangents: ObstacleTangent) = TangentPath(listOf(*tangents))
/**
* Create inner and outer tangents between two circles.
* This method returns a map of segments using [DubinsPath] connection type notation.
*/
internal fun tangentsBetweenCircles(
first: Circle2D,
second: Circle2D,
): Map<DubinsPath.Type, LineSegment2D> = with(Euclidean2DSpace) {
// Distance between centers
val distanceBetweenCenters: Double = first.center.distanceTo(second.center)
// return empty map if one circle is inside another
val minRadius = min(first.radius, second.radius)
val maxRadius = max(first.radius, second.radius)
val listOfTangents = when {
// one circle inside another, no tangents
distanceBetweenCenters + minRadius <= maxRadius -> return emptyMap()
// circles intersect, only outer tangents
distanceBetweenCenters - minRadius <= maxRadius -> listOf(DubinsPath.Type.RSR, DubinsPath.Type.LSL)
// no intersections all tangents
else -> listOf(DubinsPath.Type.RSR, DubinsPath.Type.RSL, DubinsPath.Type.LSR, DubinsPath.Type.LSL)
}
val angle1 = atan2(second.center.x - first.center.x, second.center.y - first.center.y)
return listOfTangents.associateWith { route ->
val r1 = when (route.first) {
Trajectory2D.L -> -first.radius
Trajectory2D.R -> first.radius
}
val r2 = when (route.third) {
Trajectory2D.L -> -second.radius
Trajectory2D.R -> second.radius
}
val r = if (r1.sign == r2.sign) {
r1.absoluteValue - r2.absoluteValue
} else {
r1.absoluteValue + r2.absoluteValue
}
val l = sqrt(distanceBetweenCenters * distanceBetweenCenters - r * r)
val angle2 = if (r1.absoluteValue > r2.absoluteValue) {
angle1 + r1.sign * atan2(r.absoluteValue, l)
} else {
angle1 - r2.sign * atan2(r.absoluteValue, l)
}
val w = vector(-cos(angle2), sin(angle2))
LineSegment(
first.center + w * r1,
second.center + w * r2
)
}
}
private fun Circle2D.isInside(other: Circle2D): Boolean {
return center.distanceTo(other.center) + radius <= other.radius
}
internal class ObstacleShell(
nodes: List<Circle2D>,
) : Obstacle {
override val circles: List<Circle2D>
override val center: Vector2D<Double>
private val shell: List<LineSegment2D>
private val shellDirection: Trajectory2D.Direction
init {
this.center = Euclidean2DSpace.vector(
nodes.sumOf { it.center.x } / nodes.size,
nodes.sumOf { it.center.y } / nodes.size
)
// this.circles = nodes.filter { node ->
// //filter nodes inside other nodes
// nodes.none{ node !== it && node.isInside(it) }
// }
this.circles = nodes.distinct()
if (nodes.size < 2) {
shell = emptyList()
shellDirection = Trajectory2D.R
} else {
//ignore cases when one circle is inside another one
val lslTangents = circles.zipWithNextCircular { a, b ->
tangentsBetweenCircles(a, b)[DubinsPath.Type.LSL] ?: error("Intersecting circles")
}
val rsrTangents = circles.zipWithNextCircular { a, b ->
tangentsBetweenCircles(a, b)[DubinsPath.Type.RSR] ?: error("Intersecting circles")
}
val lslToCenter = lslTangents.sumOf { it.begin.distanceTo(center) } +
lslTangents.sumOf { it.end.distanceTo(center) }
val rsrToCenter = rsrTangents.sumOf { it.begin.distanceTo(center) } +
rsrTangents.sumOf { it.end.distanceTo(center) }
if (rsrToCenter >= lslToCenter) {
this.shell = rsrTangents
this.shellDirection = Trajectory2D.R
} else {
this.shell = lslTangents
this.shellDirection = Trajectory2D.L
}
}
}
constructor(obstacle: Obstacle) : this(obstacle.circles)
/**
* Check if segment has any intersections with this obstacle
*/
override fun intersects(segment: LineSegment2D): Boolean =
shell.any { tangent -> segment.intersectsSegment(tangent) }
|| circles.any { circle -> segment.intersectsCircle(circle) }
override fun intersects(circle: Circle2D): Boolean =
shell.any { tangent -> tangent.intersectsCircle(circle) }
/**
* Tangent to next obstacle node in given direction
*/
fun nextTangent(circleIndex: Int, direction: Trajectory2D.Direction): ObstacleTangent {
if (circleIndex == -1) error("Circle does not belong to this tangent")
val nextCircleIndex = if (direction == this.shellDirection) {
if (circleIndex == circles.lastIndex) 0 else circleIndex + 1
} else {
if (circleIndex == 0) circles.lastIndex else circleIndex - 1
}
return ObstacleTangent(
LineSegment(
shell[nextCircleIndex].end,
shell[nextCircleIndex].begin
),
ObstacleConnection(this, circleIndex, direction),
ObstacleConnection(this, nextCircleIndex, direction),
)
}
/**
* All tangents in given direction
*/
internal fun tangentsAlong(
initialCircleIndex: Int,
finalCircleIndex: Int,
direction: Trajectory2D.Direction,
): List<ObstacleTangent> {
return buildList {
var currentIndex = initialCircleIndex
do {
val tangent = nextTangent(currentIndex, direction)
add(tangent)
currentIndex = tangent.endNode.nodeIndex
} while (currentIndex != finalCircleIndex)
}
}
override fun equals(other: Any?): Boolean {
if (other == null || other !is ObstacleShell) return false
return circles == other.circles
}
override fun hashCode(): Int {
return circles.hashCode()
}
}
internal fun ObstacleShell(vararg circles: Circle2D): ObstacleShell = ObstacleShell(listOf(*circles))
private fun LineSegment2D.intersectsSegment(other: LineSegment2D): Boolean {
infix fun DoubleVector2D.cross(v2: DoubleVector2D): Double = x * v2.y - y * v2.x
infix fun DoubleVector2D.crossSign(v2: DoubleVector2D) = cross(v2).sign
return with(Euclidean2DSpace) {
(other.begin - begin) crossSign (other.end - begin) !=
(other.begin - end) crossSign (other.end - end) &&
(begin - other.begin) crossSign (end - other.begin) !=
(begin - other.end) crossSign (end - other.end)
}
}
private fun LineSegment2D.intersectsCircle(circle: Circle2D): Boolean {
val a = (begin.x - end.x).pow(2.0) + (begin.y - end.y).pow(2.0)
val b = 2 * ((begin.x - end.x) * (end.x - circle.center.x) +
(begin.y - end.y) * (end.y - circle.center.y))
val c = (end.x - circle.center.x).pow(2.0) + (end.y - circle.center.y).pow(2.0) -
circle.radius.pow(2.0)
val aNormalized = a / (a * a + b * b + c * c)
val bNormalized = b / (a * a + b * b + c * c)
val cNormalized = c / (a * a + b * b + c * c)
val d = bNormalized.pow(2.0) - 4 * aNormalized * cNormalized
if (d < 1e-6) {
return false
} else {
val t1 = (-bNormalized - d.pow(0.5)) * 0.5 / aNormalized
val t2 = (-bNormalized + d.pow(0.5)) * 0.5 / aNormalized
if (((0 < t1) and (t1 < 1)) or ((0 < t2) and (t2 < 1))) {
return true
}
}
return false
}
/**
* All tangents between two obstacles
*
* In general generates 4 paths.
* TODO check intersections.
*/
private fun outerTangents(first: Obstacle, second: Obstacle): Map<DubinsPath.Type, ObstacleTangent> = buildMap {
for (firstCircleIndex in first.circles.indices) {
for (secondCircleIndex in second.circles.indices) {
for ((pathType, segment) in tangentsBetweenCircles(
first.circles[firstCircleIndex],
second.circles[secondCircleIndex]
)) {
val tangent = ObstacleTangent(
segment,
ObstacleConnection(first, firstCircleIndex, pathType.first),
ObstacleConnection(second, secondCircleIndex, pathType.third)
)
if (!(first.intersects(tangent)) && !(second.intersects(tangent))) {
put(
pathType,
tangent
)
}
}
}
}
}
private fun arcLength(
circle: Circle2D,
point1: DoubleVector2D,
point2: DoubleVector2D,
direction: Trajectory2D.Direction,
): Double {
val phi1 = atan2(point1.y - circle.center.y, point1.x - circle.center.x)
val phi2 = atan2(point2.y - circle.center.y, point2.x - circle.center.x)
var angle = 0.0
when (direction) {
Trajectory2D.L -> {
angle = if (phi2 >= phi1) {
phi2 - phi1
} else {
2 * PI + phi2 - phi1
}
}
Trajectory2D.R -> {
angle = if (phi2 >= phi1) {
2 * PI - (phi2 - phi1)
} else {
-(phi2 - phi1)
}
}
}
return circle.radius * angle
}
private fun normalVectors(v: DoubleVector2D, r: Double): Pair<DoubleVector2D, DoubleVector2D> {
return Pair(
r * Euclidean2DSpace.vector(v.y / Euclidean2DSpace.norm(v), -v.x / Euclidean2DSpace.norm(v)),
r * Euclidean2DSpace.vector(-v.y / Euclidean2DSpace.norm(v), v.x / Euclidean2DSpace.norm(v))
)
}
private fun constructTangentCircles(
point: DoubleVector2D,
direction: DoubleVector2D,
r: Double,
): LR<Circle2D> {
val center1 = point + normalVectors(direction, r).first
val center2 = point + normalVectors(direction, r).second
val p1 = center1 - point
return if (atan2(p1.y, p1.x) - atan2(direction.y, direction.x) in listOf(PI / 2, -3 * PI / 2)) {
LR(
Circle2D(center1, r),
Circle2D(center2, r)
)
} else {
LR(
Circle2D(center2, r),
Circle2D(center1, r)
)
}
}
private fun sortedObstacles(
currentObstacle: Obstacle,
obstacles: List<Obstacle>,
): List<Obstacle> {
return obstacles.sortedBy { Euclidean2DSpace.norm(it.center - currentObstacle.center) }
}
/**
* Check if all proposed paths have ended at [finalObstacle]
*/
private fun allFinished(
paths: List<TangentPath>,
finalObstacle: Obstacle,
): Boolean {
for (path in paths) {
if (path.last().endNode.obstacle !== finalObstacle) {
return false
}
}
return true
}
private fun LineSegment2D.toTrajectory() = StraightTrajectory2D(begin, end)
private fun TangentPath.toTrajectory(): CompositeTrajectory2D = CompositeTrajectory2D(
buildList {
tangents.zipWithNext().forEach { (left, right: ObstacleTangent) ->
add(left.lineSegment.toTrajectory())
add(
CircleTrajectory2D.of(
right.startCircle.center,
left.lineSegment.end,
right.lineSegment.begin,
right.startDirection
)
)
}
add(tangents.last().lineSegment.toTrajectory())
}
)
internal fun findAllPaths(
start: DubinsPose2D,
startingRadius: Double,
finish: DubinsPose2D,
finalRadius: Double,
obstacles: List<ObstacleShell>,
): List<CompositeTrajectory2D> {
fun DubinsPose2D.direction() = Euclidean2DSpace.vector(cos(bearing), sin(bearing))
// two circles for the initial point
val initialCircles = constructTangentCircles(
start,
start.direction(),
startingRadius
)
//two circles for the final point
val finalCircles = constructTangentCircles(
finish,
finish.direction(),
finalRadius
)
//all valid trajectories
val trajectories = mutableListOf<CompositeTrajectory2D>()
for (i in listOf(Trajectory2D.L, Trajectory2D.R)) {
for (j in listOf(Trajectory2D.L, Trajectory2D.R)) {
//Using obstacle to minimize code bloat
val initialObstacle = ObstacleShell(initialCircles[i])
val finalObstacle = ObstacleShell(finalCircles[j])
var currentPaths: List<TangentPath> = listOf(
TangentPath(
//We need only the direction of the final segment from this
ObstacleTangent(
LineSegment(start, start),
ObstacleConnection(initialObstacle, 0, i),
ObstacleConnection(initialObstacle, 0, i),
)
)
)
while (!allFinished(currentPaths, finalObstacle)) {
// paths after next obstacle iteration
val newPaths = mutableListOf<TangentPath>()
// for each path propagate it one obstacle further
for (tangentPath: TangentPath in currentPaths) {
val currentNode = tangentPath.last().endNode
val currentDirection: Trajectory2D.Direction = tangentPath.last().endDirection
val currentObstacle: ObstacleShell = ObstacleShell(tangentPath.last().endNode.obstacle)
// If path is finished, ignore it
// TODO avoid returning to ignored obstacle on the next cycle
if (currentObstacle == finalObstacle) {
newPaths.add(tangentPath)
} else {
val tangentToFinal: ObstacleTangent =
outerTangents(currentObstacle, finalObstacle)[DubinsPath.Type(
currentDirection,
Trajectory2D.S,
j
)] ?: break
// searching for the nearest obstacle that intersects with the direct path
val nextObstacle = sortedObstacles(currentObstacle, obstacles).find { obstacle ->
obstacle.intersects(tangentToFinal)
} ?: finalObstacle
//TODO add break check for end of path
// All valid tangents from current obstacle to the next one
val nextTangents: Collection<ObstacleTangent> = outerTangents(
currentObstacle,
nextObstacle
).filter { (key, tangent) ->
obstacles.none { obstacle -> obstacle.intersects(tangent) } && // does not intersect other obstacles
key.first == currentDirection && // initial direction is the same as end of previous segment direction
(nextObstacle != finalObstacle || key.third == j) // if it is the last, it should be the same as the one we are searching for
}.values
for (tangent in nextTangents) {
val tangentsAlong = if (tangent.startCircle === tangentPath.last().endCircle) {
//if the previous segment last circle is the same as first circle of the next segment
//If obstacle consists of single circle, do not walk around
if (currentObstacle.circles.size < 2) {
emptyList()
} else {
val lengthMaxPossible = arcLength(
tangent.startCircle,
tangentPath.last().lineSegment.end,
currentObstacle.nextTangent(
tangent.beginNode.nodeIndex,
currentDirection
).lineSegment.begin,
currentDirection
)
val lengthCalculated = arcLength(
tangent.startCircle,
tangentPath.last().lineSegment.end,
tangent.lineSegment.begin,
currentDirection
)
// ensure that path does not go inside the obstacle
if (lengthCalculated > lengthMaxPossible) {
currentObstacle.tangentsAlong(
currentNode.nodeIndex,
tangent.beginNode.nodeIndex,
currentDirection,
)
} else {
emptyList()
}
}
} else {
currentObstacle.tangentsAlong(
currentNode.nodeIndex,
tangent.beginNode.nodeIndex,
currentDirection,
)
}
newPaths.add(TangentPath(tangentPath.tangents + tangentsAlong + tangent))
}
}
}
currentPaths = newPaths
}
trajectories += currentPaths.map { tangentPath ->
// val lastDirection: Trajectory2D.Direction = tangentPath.last().endDirection
val end = Obstacle(finalCircles[j])
TangentPath(
tangentPath.tangents +
ObstacleTangent(
LineSegment(finish, finish),
ObstacleConnection(end, 0, j),
ObstacleConnection(end, 0, j)
)
)
}.map { it.toTrajectory() }
}
}
return trajectories
}

View File

@ -3,21 +3,19 @@
* Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
*/
package space.kscience.trajectory.segments
package space.kscience.kmath.geometry
import space.kscience.kmath.geometry.Circle2D
import space.kscience.kmath.geometry.Euclidean2DSpace
import space.kscience.kmath.geometry.circumference
import space.kscience.kmath.geometry.degrees
import space.kscience.trajectory.CircleTrajectory2D
import space.kscience.trajectory.DubinsPose2D
import space.kscience.trajectory.Trajectory2D
import kotlin.math.PI
import kotlin.test.Test
import kotlin.test.assertEquals
class ArcTests {
@Test
fun arcTest() = with(Euclidean2DSpace){
fun arc() = with(Euclidean2DSpace) {
val circle = Circle2D(vector(0.0, 0.0), 2.0)
val arc = CircleTrajectory2D.of(
circle.center,
@ -26,7 +24,19 @@ class ArcTests {
Trajectory2D.R
)
assertEquals(circle.circumference / 4, arc.length, 1.0)
assertEquals(0.0, arc.start.bearing.degrees)
assertEquals(0.0, arc.begin.bearing.degrees)
assertEquals(90.0, arc.end.bearing.degrees)
}
@Test
fun quarter() = with(Euclidean2DSpace) {
val circle = circle(1, 0, 1)
val arc = CircleTrajectory2D(
circle,
DubinsPose2D(x = 2.0, y = 1.2246467991473532E-16, bearing = PI.radians),
DubinsPose2D(x = 1.0, y = -1.0, bearing = (PI*3/2).radians)
)
assertEquals(Trajectory2D.R, arc.direction)
assertEquals(PI / 2, arc.length, 1e-4)
}
}

View File

@ -0,0 +1,135 @@
/*
* Copyright 2018-2022 KMath contributors.
* Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
*/
package space.kscience.kmath.geometry
import kotlin.math.pow
import kotlin.math.sqrt
import kotlin.test.Test
import kotlin.test.assertEquals
import kotlin.test.assertFalse
import kotlin.test.assertTrue
class CircleTests {
@Test
fun circle() {
val center = Euclidean2DSpace.vector(0.0, 0.0)
val radius = 2.0
val expectedCircumference = 12.56637
val circle = Circle2D(center, radius)
assertEquals(expectedCircumference, circle.circumference, 1e-4)
}
@Test
fun circleIntersection() = with(Euclidean2DSpace) {
assertTrue {
intersectsOrInside(
circle(0.0, 0.0, 1.0),
circle(0.0, 0.0, 2.0)
)
}
assertTrue {
intersectsOrInside(
circle(0.0, 1.0, 1.0),
circle(0.0, 0.0, 1.0)
)
}
assertFalse {
intersectsOrInside(
circle(0.0, 1.0, 1.0),
circle(0.0, -1.1, 1.0)
)
}
}
@Test
fun circleLineIntersection() = with(Euclidean2DSpace) {
assertTrue {
intersects(circle(0, 0, 1), segment(1, 1, -1, 1))
}
assertTrue {
intersects(circle(1, 1, sqrt(2.0)/2), segment(1, 0, 0, 1))
}
assertTrue {
intersects(circle(1, 1, 1), segment(2, 2, 0, 2))
}
assertTrue {
intersects(circle(0, 0, 1), segment(1, -1, 1, 1))
}
assertTrue {
intersects(circle(0, 0, 1), segment(1, 0, -1, 0))
}
assertFalse {
intersects(circle(0, 0, 1), segment(1, 2, -1, 2))
}
assertFalse {
intersects(circle(-1, 0, 1), segment(0, 1.05, -2, 1.0))
}
}
private fun Euclidean2DSpace.oldIntersect(circle: Circle2D, segment: LineSegment2D): Boolean{
val begin = segment.begin
val end = segment.end
val lengthSquared = (begin.x - end.x).pow(2) + (begin.y - end.y).pow(2)
val b = 2 * ((begin.x - end.x) * (end.x - circle.center.x) +
(begin.y - end.y) * (end.y - circle.center.y))
val c = (end.x - circle.center.x).pow(2) + (end.y - circle.center.y).pow(2) -
circle.radius.pow(2)
val aNormalized = lengthSquared / (lengthSquared * lengthSquared + b * b + c * c)
val bNormalized = b / (lengthSquared * lengthSquared + b * b + c * c)
val cNormalized = c / (lengthSquared * lengthSquared + b * b + c * c)
val d = bNormalized.pow(2.0) - 4 * aNormalized * cNormalized
if (d < 1e-6) {
return false
} else {
val t1 = (-bNormalized - d.pow(0.5)) * 0.5 / aNormalized
val t2 = (-bNormalized + d.pow(0.5)) * 0.5 / aNormalized
if (((0 < t1) and (t1 < 1)) or ((0 < t2) and (t2 < 1))) {
return true
}
}
return false
}
@Test
fun oldCircleLineIntersection() = with(Euclidean2DSpace){
assertTrue {
oldIntersect(circle(0, 0, 1.1), segment(1, 1, -1, 1))
}
assertTrue {
oldIntersect(circle(1, 1, sqrt(2.0)/2+0.01), segment(1, 0, 0, 1))
}
assertTrue {
oldIntersect(circle(1, 1, 1.01), segment(2, 2, 0, 2))
}
assertTrue {
oldIntersect(circle(0, 0, 1.01), segment(1, -1, 1, 1))
}
assertTrue {
oldIntersect(circle(0, 0, 1.0), segment(2, 0, -2, 0))
}
assertFalse {
oldIntersect(circle(0, 0, 1), segment(1, 2, -1, 2))
}
assertFalse {
oldIntersect(circle(-1, 0, 1), segment(0, 1.05, -2, 1.0))
}
}
}

View File

@ -3,10 +3,8 @@
* Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
*/
package space.kscience.trajectory.segments
package space.kscience.kmath.geometry
import space.kscience.kmath.geometry.Euclidean2DSpace
import space.kscience.kmath.geometry.degrees
import space.kscience.trajectory.StraightTrajectory2D
import kotlin.math.pow
import kotlin.math.sqrt

View File

@ -45,16 +45,16 @@ class DubinsTests {
val b = path.segments[1]
val c = path.segments[2] as CircleTrajectory2D
assertTrue(start.equalsFloat(a.start))
assertTrue(end.equalsFloat(c.end))
assertEquals(start, a.begin)
assertEquals(end, c.end)
// Not working, theta double precision inaccuracy
if (b is CircleTrajectory2D) {
assertTrue(a.end.equalsFloat(b.start))
assertTrue(c.start.equalsFloat(b.end))
assertEquals(a.end, b.begin)
assertEquals(c.begin, b.end)
} else if (b is StraightTrajectory2D) {
assertTrue(a.end.equalsFloat(DubinsPose2D(b.begin, b.bearing)))
assertTrue(c.start.equalsFloat(DubinsPose2D(b.end, b.bearing)))
assertEquals(a.end, DubinsPose2D(b.begin, b.bearing))
assertEquals(c.begin, DubinsPose2D(b.end, b.bearing))
}
}
}

View File

@ -8,38 +8,51 @@ package space.kscience.trajectory
import space.kscience.kmath.geometry.Circle2D
import space.kscience.kmath.geometry.Euclidean2DSpace.vector
import space.kscience.kmath.geometry.degrees
import kotlin.math.PI
import kotlin.test.Test
import kotlin.test.assertEquals
import kotlin.test.assertTrue
class ObstacleTest {
@Test
fun firstPath() {
fun equalObstacles() {
val circle1 = Circle2D(vector(1.0, 6.5), 0.5)
val circle2 = Circle2D(vector(1.0, 6.5), 0.5)
assertEquals(circle1, circle2)
val obstacle1 = Obstacle(circle1)
val obstacle2 = Obstacle(circle2)
assertEquals(obstacle1, obstacle2)
}
@Test
fun singeObstacle() {
val startPoint = vector(-5.0, -1.0)
val startDirection = vector(1.0, 1.0)
val startRadius = 0.5
val finalPoint = vector(20.0, 4.0)
val finalDirection = vector(1.0, -1.0)
val outputTangents = Obstacle.avoidObstacles(
val outputTangents = Obstacles.avoidObstacles(
DubinsPose2D(startPoint, startDirection),
DubinsPose2D(finalPoint, finalDirection),
startRadius,
Obstacle(Circle2D(vector(7.0, 1.0), 5.0))
)
assertTrue { outputTangents.isNotEmpty() }
val length = outputTangents.minOf { it.length }
assertEquals(27.2113183, length, 1e-6)
}
@Test
fun secondPath() {
fun twoObstacles() {
val startPoint = vector(-5.0, -1.0)
val startDirection = vector(1.0, 1.0)
val radius = 0.5
val finalPoint = vector(20.0, 4.0)
val finalDirection = vector(1.0, -1.0)
val paths = Obstacle.avoidObstacles(
val paths = Obstacles.avoidObstacles(
DubinsPose2D(startPoint, startDirection),
DubinsPose2D(finalPoint, finalDirection),
radius,
@ -55,19 +68,36 @@ class ObstacleTest {
Circle2D(vector(9.0, 4.0), 0.5)
)
)
assertTrue { paths.isNotEmpty() }
val length = paths.minOf { it.length }
assertEquals(28.9678224, length, 1e-6)
}
@Test
fun nearPoints() {
fun circumvention(){
val obstacle = Obstacle(
Circle2D(vector(0.0, 0.0), 1.0),
Circle2D(vector(0.0, 1.0), 1.0),
Circle2D(vector(1.0, 1.0), 1.0),
Circle2D(vector(1.0, 0.0), 1.0)
)
val circumvention = obstacle.circumvention
assertEquals(4, circumvention.segments.count { it is CircleTrajectory2D })
assertEquals(4 + 2* PI, circumvention.length, 1e-4)
}
@Test
fun closePoints() {
val startPoint = vector(-1.0, -1.0)
val startDirection = vector(0.0, 1.0)
val startRadius = 1.0
val finalPoint = vector(-1, -1)
val finalDirection = vector(1.0, 0)
val paths = Obstacle.avoidObstacles(
val paths = Obstacles.avoidObstacles(
DubinsPose2D(startPoint, startDirection),
DubinsPose2D(finalPoint, finalDirection),
startRadius,
@ -78,14 +108,15 @@ class ObstacleTest {
Circle2D(vector(1.0, 0.0), 1.0)
)
)
assertTrue { paths.isNotEmpty() }
val length = paths.minOf { it.length }
println(length)
//assertEquals(28.9678224, length, 1e-6)
}
@Test
fun fromMap() {
val paths = Obstacle.avoidObstacles(
fun largeCoordinates() {
val paths = Obstacles.avoidObstacles(
DubinsPose2D(x = 484149.535516561, y = 2995086.2534208703, bearing = 3.401475378237137.degrees),
DubinsPose2D(x = 456663.8489126448, y = 2830054.1087567504, bearing = 325.32183928982727.degrees),
5000.0,
@ -98,34 +129,6 @@ class ObstacleTest {
)
)
assertTrue { paths.isNotEmpty() }
val length = paths.minOf { it.length }
}
@Test
fun fromMapLess() {
val paths = Obstacle.avoidObstacles(
DubinsPose2D(x = 48.4149535516561, y = 299.50862534208703, bearing = 3.401475378237137.degrees),
DubinsPose2D(x = 45.66638489126448, y = 283.00541087567504, bearing = 325.32183928982727.degrees),
0.5,
Obstacle(
Circle2D(vector(x=44.60882236175772, y=289.52640759535935), radius=0.5),
Circle2D(vector(x=45.558751549431164, y=289.71165594902174), radius=0.5),
Circle2D(vector(x=46.590308440141426, y=289.3897500160981), radius=0.5),
Circle2D(vector(x=46.242119397653354, y=287.94964842121634), radius=0.5),
Circle2D(vector(x=44.92318047505464, y=288.0132403305273), radius=0.5)
)
)
val length = paths.minOf { it.length }
}
@Test
fun equalObstacles() {
val circle1 = Circle2D(vector(1.0, 6.5), 0.5)
val circle2 = Circle2D(vector(1.0, 6.5), 0.5)
assertEquals(circle1, circle2)
val obstacle1 = ObstacleShell(listOf(circle1))
val obstacle2 = ObstacleShell(listOf(circle2))
assertEquals(obstacle1, obstacle2)
}
}

View File

@ -1,24 +0,0 @@
/*
* Copyright 2018-2022 KMath contributors.
* Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
*/
package space.kscience.trajectory.segments
import space.kscience.kmath.geometry.Circle2D
import space.kscience.kmath.geometry.Euclidean2DSpace
import space.kscience.kmath.geometry.circumference
import kotlin.test.Test
import kotlin.test.assertEquals
class CircleTests {
@Test
fun arcTest() {
val center = Euclidean2DSpace.vector(0.0, 0.0)
val radius = 2.0
val expectedCircumference = 12.56637
val circle = Circle2D(center, radius)
assertEquals(expectedCircumference, circle.circumference, 1e-4)
}
}

View File

@ -6,13 +6,15 @@
package space.kscience.trajectory
import space.kscience.kmath.geometry.Euclidean2DSpace
import space.kscience.kmath.geometry.equalsFloat
import space.kscience.kmath.geometry.radians
import space.kscience.kmath.geometry.sin
fun DubinsPose2D.equalsFloat(other: DubinsPose2D) =
x.equalsFloat(other.x) && y.equalsFloat(other.y) && bearing.radians.equalsFloat(other.bearing.radians)
fun assertEquals(expected: DubinsPose2D, actual: DubinsPose2D, precision: Double = 1e-6){
kotlin.test.assertEquals(expected.x, actual.x, precision)
kotlin.test.assertEquals(expected.y, actual.y, precision)
kotlin.test.assertEquals(expected.bearing.radians, actual.bearing.radians, precision)
}
fun StraightTrajectory2D.inverse() = StraightTrajectory2D(end, begin)