refactor lines and segments

kmath-geometry/src/commonMain/kotlin/space/kscience/kmath/geometry/Line.kt

@@ -5,15 +5,23 @@
 
 package space.kscience.kmath.geometry
 
+import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
-import space.kscience.kmath.operations.DoubleField.pow
 
 /**
- * A line formed by [base] vector of start and a [direction] vector. Direction vector is not necessarily normalized,
+ * A line formed by [start] vector of start and a [direction] vector. Direction vector is not necessarily normalized,
  * but its length does not affect line properties
  */
+public interface Line<out V : Vector> {
+    public val start: V
+    public val direction: V
+}
+
 @Serializable
-public data class Line<out V : Vector>(val base: V, val direction: V)
+@SerialName("Line")
+private data class LineImpl<out V : Vector>(override val start: V, override val direction: V): Line<V>
+
+public fun <V : Vector> Line(base: V, direction: V): Line<V> = LineImpl(base, direction)
 
 public typealias Line2D = Line<DoubleVector2D>
 public typealias Line3D = Line<DoubleVector3D>
@@ -21,8 +29,19 @@ public typealias Line3D = Line<DoubleVector3D>
 /**
  * A directed line segment between [begin] and [end]
  */
+public interface LineSegment<out V : Vector> {
+    public val begin: V
+    public val end: V
+}
+
+/**
+ * Basic implementation for [LineSegment]
+ */
 @Serializable
-public data class LineSegment<out V : Vector>(val begin: V, val end: V)
+@SerialName("LineSegment")
+private data class LineSegmentImpl<out V : Vector>(override val begin: V, override val end: V) : LineSegment<V>
+
+public fun <V : Vector> LineSegment(begin: V, end: V): LineSegment<V> = LineSegmentImpl(begin, end)
 
 public fun <V : Vector> LineSegment<V>.line(algebra: GeometrySpace<V>): Line<V> = with(algebra) {
     Line(begin, end - begin)

kmath-geometry/src/commonMain/kotlin/space/kscience/kmath/geometry/projections.kt

@@ -13,7 +13,7 @@ package space.kscience.kmath.geometry
  * @param line line to which vector should be projected
  */
 public fun <V : Vector> GeometrySpace<V>.projectToLine(vector: V, line: Line<V>): V = with(line) {
-    base + (direction dot (vector - base)) / (direction dot direction) * direction
+    start + (direction dot (vector - start)) / (direction dot direction) * direction
 }
 
 /**

kmath-trajectory/src/commonMain/kotlin/space/kscience/kmath/trajectory/Obstacle.kt

@@ -23,7 +23,7 @@ internal data class Tangent(
     val lineSegment: LineSegment2D,
     val startDirection: Trajectory2D.Direction,
     val endDirection: Trajectory2D.Direction = startDirection,
-)
+): LineSegment2D by lineSegment
 
 private class TangentPath(val tangents: List<Tangent>) {
     fun last() = tangents.last()
@@ -128,7 +128,7 @@ private fun dubinsTangentsToCircles(
                         endCircle = secondCircle,
                         startObstacle = firstObstacle,
                         endObstacle = secondObstacle,
-                        lineSegment = LineSegment2D(
+                        lineSegment = LineSegment(
                             firstCircle.center + w * r1,
                             secondCircle.center + w * r2
                         ),
@@ -192,7 +192,7 @@ public class Obstacle(
                                 other,
                                 this@Obstacle,
                                 this@Obstacle,
-                                LineSegment2D(
+                                LineSegment(
                                     center + w * r1,
                                     other.center + w * r2
                                 ),
@@ -245,7 +245,7 @@ public class Obstacle(
                             circles[i - 1],
                             this,
                             this,
-                            LineSegment2D(
+                            LineSegment(
                                 tangents[i - 1].lineSegment.end,
                                 tangents[i - 1].lineSegment.begin
                             ),
@@ -257,7 +257,7 @@ public class Obstacle(
                             circles.last(),
                             this,
                             this,
-                            LineSegment2D(
+                            LineSegment(
                                 tangents.last().lineSegment.end,
                                 tangents.last().lineSegment.begin
                             ),
@@ -493,7 +493,7 @@ internal fun findAllPaths(
                         initialCircles[i]!!,
                         Obstacle(listOf(initialCircles[i]!!)),
                         Obstacle(listOf(initialCircles[i]!!)),
-                        LineSegment2D(start, start),
+                        LineSegment(start, start),
                         i
                     )
                 )
@@ -582,7 +582,7 @@ internal fun findAllPaths(
                                 end,
                                 Obstacle(end),
                                 Obstacle(end),
-                                LineSegment2D(finish, finish),
+                                LineSegment(finish, finish),
                                 startDirection = lastDirection,
                                 endDirection = j
                             )

kmath-trajectory/src/commonMain/kotlin/space/kscience/kmath/trajectory/Trajectory2D.kt

@@ -50,7 +50,7 @@ public data class StraightTrajectory2D(
     public val bearing: Angle get() = (atan2(end.x - start.x, end.y - start.y).radians).normalized()
 }
 
-public fun StraightTrajectory2D.toSegment(): LineSegment<Vector2D<Double>> = LineSegment2D(start, end)
+public fun StraightTrajectory2D.toSegment(): LineSegment<Vector2D<Double>> = LineSegment(start, end)
 
 /**
  * An arc segment