expose createEmptyPolygon, reverse, makeValid (#169)

* expose createEmptyPolygon, reverse, makeValid

* v0.8.2

* move tests for lineMerge and friends

Author: jw3126

Project.toml

@@ -1,7 +1,7 @@
 name = "LibGEOS"
 uuid = "a90b1aa1-3769-5649-ba7e-abc5a9d163eb"
 license = "MIT"
-version = "0.8.1"
+version = "0.8.2"
 
 [deps]
 CEnum = "fa961155-64e5-5f13-b03f-caf6b980ea82"

src/geos_functions.jl

@@ -490,6 +490,30 @@ function createEmptyCollection(geomtype::GEOSGeomTypes, context::GEOSContext = g
     result
 end
 
+function createEmptyPolygon(context::GEOSContext = get_global_context())::Polygon
+    result = GEOSGeom_createEmptyPolygon_r(context)
+    if result == C_NULL
+        error("LibGEOS: Error in GEOSGeom_createEmptyPolygon")
+    end
+    Polygon(result, context)
+end
+
+function reverse(obj::Geometry, context::GEOSContext = get_context(obj))::LibGEOS.AbstractGeometry
+    result = GEOSReverse_r(context, obj)
+    if result == C_NULL
+        error("LibGEOS: Error in GEOSReverse_r")
+    end
+    geomFromGEOS(result, context)
+end
+
+function makeValid(obj::Geometry, context::GEOSContext = get_context(obj))::LibGEOS.AbstractGeometry
+    result = GEOSMakeValid_r(context, obj)
+    if result == C_NULL
+        error("LibGEOS: Error in GEOSMakeValid_r")
+    end
+    geomFromGEOS(result, context)
+end
+
 # Memory management
 # cloneGeom result needs to be wrapped in Geometry type
 function cloneGeom(ptr::Union{Geometry,GEOSGeom}, context::GEOSContext = get_global_context())
@@ -639,12 +663,12 @@ end
 # GEOSPolygonizer_getCutEdges
 # GEOSPolygonize_full
 
-function lineMerge(obj::Geometry, context::GEOSContext = get_context(obj))
+function lineMerge(obj::Geometry, context::GEOSContext = get_context(obj))::MultiLineString
     result = GEOSLineMerge_r(context, obj)
     if result == C_NULL
         error("LibGEOS: Error in GEOSLineMerge")
     end
-    LineString(result, context)
+    MultiLineString(result, context)
 end
 
 function simplify(obj::Geometry, tol::Real, context::GEOSContext = get_context(obj))

test/test_geos_functions.jl

@@ -1,3 +1,6 @@
+using Test
+using LibGEOS
+
 @testset "WKTWriter" begin
     # default writing options
     p = readgeom("POINT(0.12345 2.000 0.1)")
@@ -60,7 +63,7 @@ end
     seq = Vector{Float64}[[-1, 0], [0, 0], [10, 0], [10, 10], [0, 10], [-1, 0]]
     a = LibGEOS.createCoordSeq(seq)
     @test LibGEOS.isCCW(a)
-    a = LibGEOS.createCoordSeq(reverse(seq))
+    a = LibGEOS.createCoordSeq(Base.reverse(seq))
     @test !LibGEOS.isCCW(a)
 
     # Polygons and Holes
@@ -896,4 +899,19 @@ end
         # LibGEOS.getExtent(geom) == [0, 0, 1, 1]
         GeoInterface.extent(geom) == Extent(X = (0, 1), Y = (0, 1))
     end
+
+    p = LibGEOS.createEmptyPolygon()
+    @test p == readgeom("POLYGON EMPTY")
+    @test p isa Polygon
+
+    lss = readgeom("MULTILINESTRING((0 0, 0 1), (0 1, 0 2))")
+    @test lineMerge(lss) == readgeom("MULTILINESTRING ((0 0, 0 1, 0 2))")
+
+    geo_invalid = readgeom("POLYGON((0 0, 0 1, 1 1, 1 0, -1 1, 0 0))")
+    @test !LibGEOS.isValid(geo_invalid)
+    geo_valid = LibGEOS.makeValid(geo_invalid)
+    @test geo_valid isa LibGEOS.MultiPolygon
+    @test LibGEOS.isValid(geo_valid)
+
+    @test LibGEOS.reverse(readgeom("LINESTRING(0 0, 1 1)")) == readgeom("LINESTRING(1 1, 0 0)")
 end