Fix isapprox for Line (#1141)

Author: juliohm

src/geometries/primitives/line.jl

@@ -21,6 +21,7 @@ paramdim(::Type{<:Line}) = 1
 ==(l₁::Line, l₂::Line) = l₁.a ∈ l₂ && l₁.b ∈ l₂ && l₂.a ∈ l₁ && l₂.b ∈ l₁
 
 Base.isapprox(l₁::Line, l₂::Line; atol=atol(lentype(l₁)), kwargs...) =
-  isapprox(l₁.a, l₂.a; atol, kwargs...) && isapprox(l₁.b, l₂.b; atol, kwargs...)
+  isapproxzero(norm(ucross(l₁.b - l₁.a, l₂.b - l₂.a)); atol, kwargs...) &&
+  isapproxzero(norm(ucross(l₁.b - l₂.a, l₂.b - l₂.a)); atol, kwargs...)
 
 (l::Line)(t) = coordsum((l.a, l.b), weights=((1 - t), t))

src/geometries/primitives/plane.jl

@@ -44,8 +44,8 @@ normal(p::Plane) = unormalize(ucross(p.u, p.v))
   p₁(0, 0) ∈ p₂ && p₁(1, 0) ∈ p₂ && p₁(0, 1) ∈ p₂ && p₂(0, 0) ∈ p₁ && p₂(1, 0) ∈ p₁ && p₂(0, 1) ∈ p₁
 
 Base.isapprox(p₁::Plane, p₂::Plane; atol=atol(lentype(p₁)), kwargs...) =
+  isapproxzero(norm(ucross(normal(p₁), normal(p₂))); atol, kwargs...) &&
   isapproxzero(udot(p₁(0, 0) - p₂(0, 0), normal(p₂)); atol, kwargs...) &&
-  isapproxzero(udot(p₂(0, 0) - p₁(0, 0), normal(p₁)); atol, kwargs...) &&
-  isapproxzero(norm(ucross(normal(p₁), normal(p₂))); atol, kwargs...)
+  isapproxzero(udot(p₂(0, 0) - p₁(0, 0), normal(p₁)); atol, kwargs...)
 
 (p::Plane)(u, v) = p.p + u * p.u + v * p.v

test/primitives.jl

@@ -276,6 +276,18 @@ end
   @test l(T(0.75)) == latlon(45, 67.5)
   @test l(T(1)) == latlon(45, 90)
 
+  # https://github.com/JuliaGeometry/Meshes.jl/issues/1138
+  l1 = Line(cart(0, 0), cart(1, 0))
+  l2 = Line(cart(0, 0), cart(2, 0))
+  l3 = Line(cart(0, 0), cart(-1, 0))
+  l4 = Line(cart(0, 0), cart(0, 1))
+  l5 = Line(cart(0, 0), cart(0, 2))
+  l6 = Line(cart(0, 0), cart(0, -1))
+  @test l1 == l2 == l3
+  @test l1 ≈ l2 ≈ l3
+  @test l4 == l5 == l6
+  @test l4 ≈ l5 ≈ l6
+
   l = Line(cart(0, 0), cart(1, 1))
   @test sprint(show, l) == "Line(a: (x: 0.0 m, y: 0.0 m), b: (x: 1.0 m, y: 1.0 m))"
   if T === Float32