Sg/area dist debug

.gitignore

@@ -1,2 +1,3 @@
 /Manifest.toml
 /docs/build/
+.vscode/

src/methods/area.jl

@@ -71,23 +71,53 @@ computed slighly differently for different geometries:
 signed_area(geom) = signed_area(GI.trait(geom), geom)
 
 # Points
-area(::GI.PointTrait, point) = zero(typeof(GI.x(point)))
+area(::GI.PointTrait, point) = GI.isempty(point) ?
+    0 : zero(typeof(GI.x(point)))
 
 signed_area(trait::GI.PointTrait, point) = area(trait, point)
 
+# MultiPoints
+function area(::GI.MultiPointTrait, multipoint)
+    GI.isempty(multipoint) && return 0
+    np = GI.npoint(multipoint)
+    np == 0 && return 0
+    return zero(typeof(GI.x(GI.getpoint(multipoint, np))))
+end
+
+signed_area(trait::GI.MultiPointTrait, multipoint) = area(trait, multipoint)
+
 # Curves
-area(::CT, curve) where CT <: GI.AbstractCurveTrait =
-    zero(typeof(GI.x(GI.getpoint(curve, 1))))
+function area(::CT, curve) where CT <: GI.AbstractCurveTrait
+    GI.isempty(curve) && return 0
+    np = GI.npoint(curve)
+    np == 0 && return 0
+    return zero(typeof(GI.x(GI.getpoint(curve, np))))
+end
 
 signed_area(trait::CT, curve) where CT <: GI.AbstractCurveTrait =
     area(trait, curve)
 
+# MultiCurves
+function area(::MCT, multicurve) where MCT <: GI.AbstractMultiCurveTrait
+    GI.isempty(multicurve) && return 0
+    ng = GI.ngeom(multicurve)
+    ng == 0 && return 0
+    np = GI.npoint(GI.getgeom(multicurve, ng))
+    np == 0 && return 0
+    return zero(typeof(GI.x(GI.getpoint(GI.getgeom(multicurve, ng), np))))
+end
+
+signed_area(trait::MCT, curve) where MCT <: GI.AbstractMultiCurveTrait =
+    area(trait, curve)
+
 # Polygons
 area(trait::GI.PolygonTrait, geom) = abs(signed_area(trait, geom))
 
 function signed_area(::GI.PolygonTrait, poly)
+    GI.isempty(poly) && return 0
     s_area = _signed_area(GI.getexterior(poly))
     area = abs(s_area)
+    area == 0 && return area
     # Remove hole areas from total
     for hole in GI.gethole(poly)
         area -= abs(_signed_area(hole))
@@ -97,9 +127,12 @@ function signed_area(::GI.PolygonTrait, poly)
 end
 
 # MultiPolygons
-area(::GI.MultiPolygonTrait, geom) =
-    sum((area(poly) for poly in GI.getpolygon(geom)))
+area(::GI.MultiPolygonTrait, multipoly) =
+    sum((area(poly) for poly in GI.getpolygon(multipoly)), init = 0)
 
+# GeometryCollections
+area(::GI.GeometryCollectionTrait, collection) = 
+    sum((area(geom) for geom in GI.getgeom(collection)), init = 0)
 #=
 Helper function:
 
@@ -111,6 +144,7 @@ to be closed.
 function _signed_area(geom)
     # Close curve, even if last point isn't explicitly repeated 
     np = GI.npoint(geom)
+    np == 0 && return 0
     first_last_equal = equals(GI.getpoint(geom, 1), GI.getpoint(geom, np))
     np -= first_last_equal ? 1 : 0 
     # Integrate the area under the curve

test/methods/area.jl

@@ -1,6 +1,14 @@
 pt = LG.Point([0.0, 0.0])
+empty_pt = LG.readgeom("POINT EMPTY")
+mpt = LG.MultiPoint([[0.0, 0.0], [1.0, 0.0]])
+empty_mpt = LG.readgeom("MULTIPOINT EMPTY")
 l1 = LG.LineString([[0.0, 0.0], [0.5, 0.5], [1.0, 0.5]])
+empty_l = LG.readgeom("LINESTRING EMPTY")
+ml1 = LG.MultiLineString([[[0.0, 0.0], [0.5, 0.5], [1.0, 0.5]], [[0.0, 0.0], [0.0, 0.1]]])
+empty_ml = LG.readgeom("MULTILINESTRING EMPTY")
+empty_l = LG.readgeom("LINESTRING EMPTY")
 r1 = LG.LinearRing([[0.0, 0.0], [1.0, 0.0], [1.0, 2.0], [0.0, 0.0]])
+empty_r = LG.readgeom("LINEARRING EMPTY")
 p1 = LG.Polygon([
     [[10.0, 0.0], [30.0, 0.0], [30.0, 20.0], [10.0, 20.0], [10.0, 0.0]],
 ])
@@ -19,13 +27,23 @@ p4 = LG.Polygon([
         [0.0, 5.0],
     ],
 ])
+empty_p = LG.readgeom("POLYGON EMPTY")
 mp1 = LG.MultiPolygon([p2, p4])
-
+empty_mp = LG.readgeom("MULTIPOLYGON EMPTY")
+c = LG.GeometryCollection([p1, p2, r1, empty_l])
+empty_c = LG.readgeom("GEOMETRYCOLLECTION EMPTY")
 
 # Points, lines, and rings have zero area
 @test GO.area(pt) == GO.signed_area(pt) == LG.area(pt) == 0
+# @test GO.area(empty_pt) == LG.area(empty_pt) == 0
+@test GO.area(mpt) == GO.signed_area(mpt) == LG.area(mpt) == 0
+@test GO.area(empty_mpt) == LG.area(empty_mpt) == 0
 @test GO.area(l1) == GO.signed_area(l1) == LG.area(l1) == 0
+@test GO.area(empty_l) == LG.area(empty_l) == 0
+@test GO.area(ml1) == GO.signed_area(ml1) == LG.area(ml1) == 0
+@test GO.area(empty_ml) == LG.area(empty_ml) == 0
 @test GO.area(r1) == GO.signed_area(r1) == LG.area(r1) == 0
+@test GO.area(empty_r) == LG.area(empty_r) == 0
 
 # Polygons have non-zero area
 # CCW polygons have positive signed area
@@ -41,5 +59,16 @@ a2 = LG.area(p2)
 a4 = LG.area(p4)
 @test GO.area(p4) == a4
 @test GO.signed_area(p4) == -a4
+# Empty polygon
+@test GO.area(empty_p) == LG.area(empty_p) == 0
+@test GO.signed_area(empty_p) == 0
+
 # Multipolygon calculations work
 @test GO.area(mp1) == a2 + a4
+# Empty multipolygon
+@test GO.area(empty_mp) == LG.area(empty_mp) == 0
+
+# Geometry collection summed area
+@test GO.area(c) == LG.area(c)
+# Empty collection
+@test GO.area(empty_c) == LG.area(empty_c) == 0