Find the intersection of two lines: Difference between revisions

<lang kotlin>// version 1.1.2

<pre>Line y = 5.0x + -20.0 intersects line y = 0.4x + 3.0 at #<struct Point x=5.0, y=5.0>.</pre></lang>

=={{header|Scala}}==

<lang Scala>object Intersection extends App {

val (l1, l2) = (LineF(PointF(4, 0), PointF(6, 10)), LineF(PointF(0, 3), PointF(10, 7)))

def findIntersection(l1: LineF, l2: LineF): PointF = {

val a1 = l1.e.y - l1.s.y

val b1 = l1.s.x - l1.e.x

val c1 = a1 * l1.s.x + b1 * l1.s.y

val a2 = l2.e.y - l2.s.y

val b2 = l2.s.x - l2.e.x

val c2 = a2 * l2.s.x + b2 * l2.s.y

val delta = a1 * b2 - a2 * b1

// If lines are parallel, intersection point will contain infinite values

PointF((b2 * c1 - b1 * c2) / delta, (a1 * c2 - a2 * c1) / delta)

}

def l01 = LineF(PointF(0f, 0f), PointF(1f, 1f))

def l02 = LineF(PointF(1f, 2f), PointF(4f, 5f))

case class PointF(x: Float, y: Float) {

override def toString = s"{$x, $y}"

}

case class LineF(s: PointF, e: PointF)

println(findIntersection(l1, l2))

println(findIntersection(l01, l02))

}</lang>

{{Out}}See it in running in your browser by [https://scalafiddle.io/sf/DAqMtEx/0 (JavaScript)]

or by [https://scastie.scala-lang.org/WQOqakOlQnaBRFBa1PuRYw Scastie (JVM)].