Sg/update intersects (#21)

* Fix up intersection point base calculation

* Update intersects and add line tests

* Add more tests and debug intersects

* Add comments to point_in_poly

Project.toml

@@ -4,6 +4,7 @@ authors = ["Anshul Singhvi <anshulsinghvi@gmail.com> and contributors"]
 version = "0.0.1-DEV"
 
 [deps]
+CairoMakie = "13f3f980-e62b-5c42-98c6-ff1f3baf88f0"
 ExactPredicates = "429591f6-91af-11e9-00e2-59fbe8cec110"
 GeoInterface = "cf35fbd7-0cd7-5166-be24-54bfbe79505f"
 GeometryBasics = "5c1252a2-5f33-56bf-86c9-59e7332b4326"
@@ -26,7 +27,4 @@ Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = [
-    "ArchGDAL", "Distributions", "GeoFormatTypes", "GeoJSON", "LibGEOS",
-    "Random", "Test",
-]
+test = ["ArchGDAL", "Distributions", "GeoFormatTypes", "GeoJSON", "LibGEOS", "Random", "Test"]

src/methods/bools.jl

@@ -265,63 +265,66 @@ function point_in_polygon(
     end
 
     # Then check the point is inside the exterior ring
-    point_in_polygon(point, GI.getexterior(poly); ignore_boundary, check_extent=false) || return false
+    point_in_polygon(
+        point,GI.getexterior(poly);
+        ignore_boundary, check_extent=false,
+    ) || return false
 
     # Finally make sure the point is not in any of the holes,
     # flipping the boundary condition
     for ring in GI.gethole(poly)
-        point_in_polygon(point, ring; ignore_boundary=!ignore_boundary) && return false
+        point_in_polygon(
+            point, ring;
+            ignore_boundary=!ignore_boundary,
+        ) && return false
     end
     return true
 end
+
 function point_in_polygon(
     ::PointTrait, pt, 
     ::Union{LineStringTrait,LinearRingTrait}, ring; 
     ignore_boundary::Bool=false,
     check_extent::Bool=false,
 )::Bool
+    x, y = GI.x(pt), GI.y(pt)
     # Cheaply check that the point is inside the ring extent
     if check_extent
         point_in_extent(point, GI.extent(ring)) || return false
     end
-
     # Then check the point is inside the ring
     inside = false
     n = GI.npoint(ring)
     p_start = GI.getpoint(ring, 1)
     p_end = GI.getpoint(ring, n)
-
-    # Handle closed on non-closed rings
-    l = if GI.x(p_start) == GI.x(p_end) && GI.y(p_start) == GI.y(p_end) 
-        l = n - 1
-    else
-        n
+    # Handle closed vs opne rings
+    if GI.x(p_start) == GI.x(p_end) && GI.y(p_start) == GI.y(p_end) 
+        n -= 1
     end
-
     # Loop over all points in the ring
-    for i in 1:l - 1
-        j = i + 1
-
+    for i in 1:(n - 1)
+        # First point on edge
         p_i = GI.getpoint(ring, i)
-        p_j = GI.getpoint(ring, j)
-        xi = GI.x(p_i)
-        yi = GI.y(p_i)
-        xj = GI.x(p_j)
-        yj = GI.y(p_j)
-
-        on_boundary = (GI.y(pt) * (xi - xj) + yi * (xj - GI.x(pt)) + yj * (GI.x(pt) - xi) == 0) &&
-            ((xi - GI.x(pt)) * (xj - GI.x(pt)) <= 0) && ((yi - GI.y(pt)) * (yj - GI.y(pt)) <= 0)
-
+        xi, yi = GI.x(p_i), GI.y(p_i)
+        # Second point on edge (j = i + 1)
+        p_j = GI.getpoint(ring, i + 1)
+        xj, yj = GI.x(p_j), GI.y(p_j)
+        # Check if point is on the ring boundary
+        on_boundary = (  # vertex to point has same slope as edge
+            yi * (xj - x) + yj * (x - xi) == y * (xj - xi) &&
+            (xi - x) * (xj - x) <= 0 &&  # x is between xi and xj
+            (yi - y) * (yj - y) <= 0     # y is between yi and yj
+        )
         on_boundary && return !ignore_boundary
-
-        intersects = ((yi > GI.y(pt)) !== (yj > GI.y(pt))) && 
-            (GI.x(pt) < (xj - xi) * (GI.y(pt) - yi) / (yj - yi) + xi)
-
+        # Check if ray from point passes through edge
+        intersects = (
+            (yi > y) !== (yj > y) && 
+            (x < (xj - xi) * (y - yi) / (yj - yi) + xi)
+        )
         if intersects 
             inside = !inside
         end
     end
-
     return inside
 end
 
@@ -341,6 +344,7 @@ function line_on_line(t1::GI.AbstractCurveTrait, line1, t2::AbstractCurveTrait,
 end
 
 line_in_polygon(line, poly) = line_in_polygon(trait(line), line, trait(poly), poly)
+
 function line_in_polygon(
     ::AbstractCurveTrait, line, 
     ::Union{AbstractPolygonTrait,LinearRingTrait}, poly
@@ -365,19 +369,19 @@ function line_in_polygon(
 end
 
 function polygon_in_polygon(poly1, poly2)
-     # edges1, edges2 = to_edges(poly1), to_edges(poly2)
-     # extent1, extent2 = to_extent(edges1), to_extent(edges2)
-     # Check the extents intersect
-     Extents.intersects(GI.extent(poly1), GI.extent(poly2)) || return false
-
-     # Check all points in poly1 are in poly2
-     for point in GI.getpoint(poly1)
-         point_in_polygon(point, poly2) || return false
-     end
+    # edges1, edges2 = to_edges(poly1), to_edges(poly2)
+    # extent1, extent2 = to_extent(edges1), to_extent(edges2)
+    # Check the extents intersect
+    Extents.intersects(GI.extent(poly1), GI.extent(poly2)) || return false
+
+    # Check all points in poly1 are in poly2
+    for point in GI.getpoint(poly1)
+        point_in_polygon(point, poly2) || return false
+    end
 
-     # Check the line of poly1 does not intersect the line of poly2
-     line_intersects(poly1, poly2) && return false
+    # Check the line of poly1 does not intersect the line of poly2
+    #intersects(poly1, poly2) && return false
 
-     # poly1 must be in poly2
-     return true
+    # poly1 must be in poly2
+    return true
  end

src/methods/crosses.jl

@@ -55,7 +55,7 @@ end
 
 function line_crosses_line(line1, line2)
     np2 = GI.npoint(line2)
-    if line_intersects(line1, line2; meets=MEETS_CLOSED)
+    if intersects(line1, line2; meets=MEETS_CLOSED)
         for i in 1:GI.npoint(line1) - 1
             for j in 1:GI.npoint(line2) - 1
                 exclude_boundary = (j === 1 || j === np2 - 2) ? :none : :both
@@ -71,7 +71,7 @@ end
 
 function line_crosses_poly(line, poly)
     for l in flatten(AbstractCurveTrait, poly)
-        line_intersects(line, l) && return true
+        intersects(line, l) && return true
     end
     return false
 end

src/methods/disjoint.jl

@@ -38,5 +38,5 @@ function polygon_disjoint(poly1, poly2)
     for point in GI.getpoint(poly2)
         point_in_polygon(point, poly1) && return false
     end
-    return !line_intersects(poly1, poly2)
+    return !intersects(poly1, poly2)
 end