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Ray-casting algorithm: Difference between revisions
Scala version
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(Scala version) |
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Line 2,493:
[exagon] point: 10,10 is outside
</pre>
=={{header|Scala}}==
From D snippet.
<lang scala>
case class Figure(name: String, edges: ((Double, Double), (Double, Double))*) {}
object Ray_casting extends App {
import Math._
import Double._
val figures = Array(Figure("Square", ((0.0, 0.0), (10.0, 0.0)),
((10.0, 0.0), (10.0, 10.0)), ((10.0, 10.0), (0.0, 10.0)),
((0.0, 10.0), (0.0, 0.0))),
Figure("Square hole", ((0.0, 0.0), (10.0, 0.0)), ((10.0, 0.0), (10.0, 10.0)),
((10.0, 10.0), (0.0, 10.0)), ((0.0, 10.0), (0.0, 0.0)),
((2.5, 2.5), (7.5, 2.5)), ((7.5, 2.5), (7.5, 7.5)),
((7.5, 7.5), (2.5, 7.5)), ((2.5, 7.5), (2.5, 2.5))),
Figure("Strange", ((0.0, 0.0), (2.5, 2.5)), ((2.5, 2.5), (0.0, 10.0)),
((0.0, 10.0), (2.5, 7.5)), ((2.5, 7.5), (7.5, 7.5)),
((7.5, 7.5), (10.0, 10.0)), ((10.0, 10.0), (10.0, 0.0)),
((10.0, 0), (2.5, 2.5))),
Figure("Exagon", ((3.0, 0.0), (7.0, 0.0)), ((7.0, 0.0), (10.0, 5.0)),
((10.0, 5.0), (7.0, 10.0)), ((7.0, 10.0), (3.0, 10.0)),
((3.0, 10.0), (0.0, 5.0)), ((0.0, 5.0), (3.0, 0.0))))
val points = Array((5.0, 5.0), (5.0, 8.0), (-10.0, 5.0), (0.0, 5.0), (10.0, 5.0), (8.0, 5.0), (10.0, 10.0))
figures foreach { f =>
println("Is point inside figure " + f.name + '?')
points foreach { p => println(" " + p + ": " + contains(f, p)) }
println
}
private def raySegI(p: (Double, Double), e: ((Double, Double), (Double, Double))): Boolean = {
val epsilon = 0.00001
if (e._1._2 > e._2._2)
return raySegI(p, (e._2, e._1))
if (p._2 == e._1._2 || p._2 == e._2._2)
return raySegI((p._1, p._2 + epsilon), e)
if (p._2 > e._2._2 || p._2 < e._1._2 || p._1 > max(e._1._1, e._2._1))
return false
if (p._1 < min(e._1._1, e._2._1))
return true
val blue = if (abs(e._1._1 - p._1) > MinValue) (p._2 - e._1._2) / (p._1 - e._1._1) else MaxValue
val red = if (abs(e._1._1 - e._2._1) > MinValue) (e._2._2 - e._1._2) / (e._2._1 - e._1._1) else MaxValue
blue >= red
}
private def contains(f: Figure, p: (Double, Double)) = f.edges.count(raySegI(p, _)) % 2 != 0
}</lang>
=={{header|Smalltalk}}==
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