make mesh[i] return a Polytope again

Author: ffreyer

src/basic_types.jl

@@ -589,7 +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/meshes.jl

@@ -11,15 +11,15 @@ end
     f = [TriangleFace(1, 2, 3), QuadFace(1, 2, 3, 4)]
     p = Point2f[(0, 1), (1, 2), (3, 4), (4, 5)]
     m = Mesh(p, f)
-    @test collect(m) == [GeometryBasics.SVector(p[1], p[2], p[3]), GeometryBasics.SVector(p[1], p[2], p[3], p[4])]
+    @test collect(m) == [Triangle(p[1], p[2], p[3]), GeometryBasics.Quadrilateral(p[1], p[2], p[3], p[4])]
 end
 
 @testset "Heterogenous faces" begin
     # https://github.com/JuliaGeometry/GeometryBasics.jl/issues/142
     f = [TriangleFace(1, 2, 3), QuadFace(1, 2, 3, 4)]
     p = Point2f[(0, 1), (1, 2), (3, 4), (4, 5)]
     m = Mesh(p, f)
-    @test collect(m) == [GeometryBasics.SVector(p[1], p[2], p[3]), GeometryBasics.SVector(p[1], p[2], p[3], p[4])]
+    @test collect(m) == [Triangle(p[1], p[2], p[3]), GeometryBasics.Quadrilateral(p[1], p[2], p[3], p[4])]
 end
 
 @testset "Ambiguous NgonFace constructors" begin

test/runtests.jl

@@ -136,7 +136,7 @@ end
         points = connect([1, 2, 3, 4, 5, 6, 7, 8], Point{2})
         f = connect([1, 2, 3, 4], SimplexFace{4})
         mesh = Mesh(points, f)
-        @test collect(mesh) == [GeometryBasics.SVector(points...)]
+        @test collect(mesh) == [Tetrahedron(points...)]
         @test faces(mesh) == [TetrahedronFace{Int64}(1,2,3,4)]
         @test decompose(LineFace{Int64}, mesh) == LineFace{Int64}[(1, 2), (1, 3), (1, 4), (2, 3), (2, 4), (3, 4)]
         @test decompose(GLTriangleFace, mesh) == GLTriangleFace[(2, 3, 4), (1, 3, 4), (1, 2, 4), (1, 2, 3)]