fix for MeshIO

Author: SimonDanisch

src/meshes.jl

@@ -124,15 +124,19 @@ Polygon triangluation!
 """
 function mesh(polygon::AbstractVector{P}; pointtype=P, facetype=GLTriangleFace,
               normaltype=nothing, nvertices=nothing) where {P<:AbstractPoint{2}}
+
     faces = decompose(facetype, polygon)
     positions = decompose(pointtype, polygon)
+
     if nvertices !== nothing
         error("Resampling polygon not supported!")
     end
+
     if normaltype !== nothing
         n = normals(positions, faces; normaltype=normaltype)
         positions = meta(positions; normals=n)
     end
+
     return Mesh(positions, faces)
 end
 
@@ -215,3 +219,40 @@ function decompose(::UV{T}, mesh::Mesh) where {T}
         error("Mesh doesn't have UV texture coordinates")
     end
 end
+
+"""
+    pointmeta(mesh::Mesh; meta_data...)
+
+Attaches metadata to the coordinates of a mesh
+"""
+function pointmeta(mesh::Mesh; meta_data...)
+    points = coordinates(mesh)
+    attr = GeometryBasics.attributes(points)
+    delete!(attr, :position) # position == metafree(points)
+    # delete overlapping attributes so we can replace with `meta_data`
+    foreach(k-> delete!(attr, k), keys(meta_data))
+    return Mesh(meta(metafree(points); attr..., meta_data...), faces(mesh))
+end
+
+"""
+    pop_pointmeta(mesh::Mesh, property::Symbol)
+Remove `property` from point metadata.
+Returns the new mesh, and the property!
+"""
+function pop_pointmeta(mesh::Mesh, property::Symbol)
+    points = coordinates(mesh)
+    attr = GeometryBasics.attributes(points)
+    delete!(attr, :position) # position == metafree(points)
+    # delete overlapping attributes so we can replace with `meta_data`
+    m = pop!(attr, property)
+    return Mesh(meta(metafree(points); attr...), faces(mesh)), m
+end
+
+"""
+    facemeta(mesh::Mesh; meta_data...)
+
+Attaches metadata to the faces of a mesh
+"""
+function facemeta(mesh::Mesh; meta_data...)
+    return Mesh(coordinates(mesh), meta(faces(mesh); meta_data...))
+end

src/metadata.jl

@@ -80,10 +80,12 @@ macro meta_type(name, mainfield, supertype, params...)
         GeometryBasics.meta(x::AbstractVector{<: $MetaName}) = getcolumns(x, :meta)[1]
 
         function GeometryBasics.meta(main::$supertype; meta...)
+            isempty(meta) && return elements # no meta to add!
             return $MetaName(main; meta...)
         end
 
         function GeometryBasics.meta(elements::AbstractVector{T}; meta...) where T <: $supertype
+            isempty(meta) && return elements # no meta to add!
             n = length(elements)
             for (k, v) in meta
                 if v isa AbstractVector
@@ -131,35 +133,3 @@ Base.getindex(x::NgonFaceMeta, idx::Int) = getindex(metafree(x), idx)
 Base.getindex(x::SimplexFaceMeta, idx::Int) = getindex(metafree(x), idx)
 
 @meta_type(Polygon, polygon, AbstractPolygon, N, T)
-
-"""
-    pointmeta(mesh::Mesh; meta_data...)
-
-Attaches metadata to the coordinates of a mesh
-"""
-function pointmeta(mesh::Mesh; meta_data...)
-    points = coordinates(mesh)
-    attr = GeometryBasics.attributes(points)
-    delete!(attr, :position) # position == metafree(points)
-    # delete overlapping attributes so we can replace with `meta_data`
-    foreach(k-> delete!(attr, k), keys(meta_data))
-    return Mesh(meta(metafree(points); attr..., meta_data...), faces(mesh))
-end
-
-function pop_pointmeta(mesh::Mesh, property::Symbol)
-    points = coordinates(mesh)
-    attr = GeometryBasics.attributes(points)
-    delete!(attr, :position) # position == metafree(points)
-    # delete overlapping attributes so we can replace with `meta_data`
-    m = pop!(attr, property)
-    return Mesh(meta(metafree(points); attr...), faces(mesh)), m
-end
-
-"""
-    facemeta(mesh::Mesh; meta_data...)
-
-Attaches metadata to the faces of a mesh
-"""
-function facemeta(mesh::Mesh; meta_data...)
-    Mesh(coordinates(mesh), meta(faces(mesh); meta_data...))
-end

test/runtests.jl

@@ -108,7 +108,7 @@ using LinearAlgebra
             @test y == [(1, 2), (2, 3), (3, 4), (4, 5), (5, 6), (6, 1)]
 
         end
-        
+
         @testset "connected views" begin
             numbers = [1, 2, 3, 4, 5, 6]
             x = connect(numbers, Point{2})
@@ -320,4 +320,11 @@ end
     @test propertynames(m) == (:position,)
     @test colpopt === color
     @test xxpopt === xx
+    
+    @testset "creating meta" begin
+        x = Point3f0[(1,3,4)]
+        # no meta gets added, so should stay the same
+        @test meta(x) === x
+        @test meta(x, value=[1]).position === x
+    end
 end