Intersection

Intersections are implemented for various geometries and domains with the ∩ (\cap) operator:

using Meshes

s1 = Segment((0.0,0.0), (1.0,0.0))
s2 = Segment((0.5,0.0), (2.0,0.0))

s1 ∩ s2

Segment{2,Float64}
├─ Point(0.5, 0.0)
└─ Point(1.0, 0.0)

First, the intersection function computes the Intersection object, which holds the IntersectionType besides the actual geometry:

I = intersection(s1, s2)

Intersection{Segment{2, Float64}}(Overlapping, Segment((0.5, 0.0), (1.0, 0.0)))

This object supports two methods type and get to retrieve the underlying information:

type(I)

Overlapping::IntersectionType = 6

get(I)

Segment{2,Float64}
├─ Point(0.5, 0.0)
└─ Point(1.0, 0.0)

For performance-sensitive code, it is recommended to use the intersection method with three arguments, including a function to reduce the number of output types.

In the example below, we use the do syntax to restrict our attention to a subset of intersection types and to make the return type and Int value in all cases:

intersection(s1, s2) do I
  if type(I) == Crossing
    return 1
  elseif type(I) == Overlapping
    return 2
  else
    return 3
  end
end

2

IntersectionType

Intersection{G}

intersection([f], g₁, g₂)

intersection(g₁, g₂) do I
  if I isa CrossingLines
    # do something
  else
    # do nothing
  end
end

g₁ ∩ g₂