Use default getindex for vector[face] when no Polytope is generated (#246)

* use default getindex when not generating Polytopes

* revert Polytope return type for getindex

* fix tests

* make mesh[i] return a Polytope again

* test Bool operations on faces

* revert changes to volume

Author: ffreyer

src/basic_types.jl

@@ -31,14 +31,6 @@ abstract type AbstractNgonFace{N,T} <: AbstractFace{N,T} end
 
 abstract type AbstractSimplex{Dim,T} <: Polytope{Dim,T} end
 
-@propagate_inbounds function Base.getindex(points::AbstractVector{P}, face::F) where {P<: Point, F <: AbstractFace}
-    return Polytope(P, F)(map(i-> points[i], face.data))
-end
-
-@propagate_inbounds function Base.getindex(elements::AbstractVector, face::F) where {F <: AbstractFace}
-    return map(i-> elements[i], face.data)
-end
-
 @fixed_vector SimplexFace = AbstractSimplexFace
 
 const TetrahedronFace{T} = SimplexFace{4,T}
@@ -597,7 +589,12 @@ Mutating these will change the mesh.
 """
 vertex_attributes(mesh::Mesh) = getfield(mesh, :vertex_attributes)
 
-Base.getindex(mesh::Mesh, i::Integer) = mesh.position[mesh.faces[i]]
+function Base.getindex(mesh::Mesh, i::Integer)
+    f = mesh.faces[i]
+    P = Polytope(eltype(mesh.position), typeof(f))
+    return P(map(j -> mesh.position[j], f.data))
+end
+
 Base.length(mesh::Mesh) = length(mesh.faces)
 
 function Base.:(==)(a::Mesh, b::Mesh)

test/geometrytypes.jl

@@ -298,10 +298,15 @@ end
 
     ps = rand(Point2f, 10)
     f = GLTriangleFace(1, 2, 3)
-    @test ps[f] == Triangle(ps[[1,2,3]]...)
+    @test ps[f] == GeometryBasics.@SVector [ps[1], ps[2], ps[3]]
+
     data = [string(i) for i in 1:10]
     f = QuadFace(3, 4, 7, 8)
-    @test data[f] == ("3", "4", "7", "8")
+    @test data[f] == ["3", "4", "7", "8"]
+
+    @test (f .== 4) == QuadFace(false, true, false, false)
+    @test f[f .== 4] isa Vector{Int}
+    @test f[f .== 4] == [4]
 
     @test GeometryBasics.cyclic_hash(f) != GeometryBasics.cyclic_hash(QuadFace(1,2,3,4))
     @test GeometryBasics.cyclic_hash(f) == GeometryBasics.cyclic_hash(QuadFace(3,4,7,8))