Support polygons in near, within and contains. Fix a bug in intersects

types/geofilter.go

@@ -150,12 +150,9 @@ func queryTokens(qt QueryType, data string, maxDistance float64) ([]string, *Geo
 		return toks, &GeoQueryData{pt: pt, loop: l, qtype: qt}, nil
 
 	case QueryTypeContains:
-		if l != nil {
-			return nil, nil, x.Errorf("Cannot use a polygon in a contains query")
-		}
 		// For a contains query, we only need to look at the objects whose cover matches our
 		// parents. So we take our parents and prefix with the coverPrefix to look in the index.
-		return createTokens(parents, coverPrefix), &GeoQueryData{pt: pt, qtype: qt}, nil
+		return createTokens(parents, coverPrefix), &GeoQueryData{pt: pt, loop: l, qtype: qt}, nil
 
 	case QueryTypeNear:
 		if l != nil {
@@ -206,33 +203,68 @@ func (q GeoQueryData) MatchesFilter(g geom.T) bool {
 	return false
 }
 
+// WithinPolygon returns true if g1 is within g2 approximaltely.
+// Note that this is very far from accurate within function and is
+// a temporary fix.
+// TODO(Ashwin): Improve this to make it more accurate.
+func WithinPolygon(g1 *s2.Loop, g2 *s2.Loop) bool {
+	for _, point := range g1.Vertices() {
+		if !g2.ContainsPoint(point) {
+			return false
+		}
+	}
+	return true
+}
+
+// TODO(Ashwin): Improve this to make it more accurate.
+func WithinCapPolygon(g1 *s2.Loop, g2 *s2.Cap) bool {
+	for _, point := range g1.Vertices() {
+		if !g2.ContainsPoint(point) {
+			return false
+		}
+	}
+	return true
+}
+
 // returns true if the geometry represented by g is within the given loop or cap
 func (q GeoQueryData) isWithin(g geom.T) bool {
 	x.AssertTruef(q.pt != nil || q.loop != nil || q.cap != nil, "At least a point, loop or cap should be defined.")
-	gpt, ok := g.(*geom.Point)
-	if !ok {
+	gpoly, ok := g.(*geom.Polygon)
+	if ok {
 		// We will only consider points for within queries.
-		return false
+		if !ok {
+			return false
+		}
+		s2loop, err := loopFromPolygon(gpoly)
+		if err != nil {
+			return false
+		}
+		if q.loop != nil {
+			return WithinPolygon(s2loop, q.loop)
+		}
+		if q.cap != nil {
+			return WithinCapPolygon(s2loop, q.cap)
+		}
 	}
 
-	s2pt := pointFromPoint(gpt)
-	if q.pt != nil {
-		return q.pt.ApproxEqual(s2pt)
-	}
+	gpt, ok := g.(*geom.Point)
+	if ok {
+		s2pt := pointFromPoint(gpt)
+		if q.pt != nil {
+			return q.pt.ApproxEqual(s2pt)
+		}
 
-	if q.loop != nil {
-		return q.loop.ContainsPoint(s2pt)
+		if q.loop != nil {
+			return q.loop.ContainsPoint(s2pt)
+		}
+		return q.cap.ContainsPoint(s2pt)
 	}
-	return q.cap.ContainsPoint(s2pt)
+	return false
 }
 
 // returns true if the geometry represented by uid/attr contains the given point
 func (q GeoQueryData) contains(g geom.T) bool {
 	x.AssertTruef(q.pt != nil || q.loop != nil, "At least a point or loop should be defined.")
-	if q.loop != nil {
-		// We don't support polygons containing polygons yet.
-		return false
-	}
 
 	poly, ok := g.(*geom.Polygon)
 	if !ok {
@@ -244,6 +276,11 @@ func (q GeoQueryData) contains(g geom.T) bool {
 	if err != nil {
 		return false
 	}
+	// If its a loop check if it lies within other loop. Else Check the point.
+	if q.loop != nil {
+		// We don't support polygons containing polygons yet.
+		return WithinPolygon(q.loop, s2loop)
+	}
 	return s2loop.ContainsPoint(*q.pt)
 }
 

types/geofilter_test.go

@@ -79,7 +79,7 @@ func TestQueryTokensPolygon(t *testing.T) {
 		if qt == QueryTypeWithin {
 			require.Len(t, toks, 18)
 		} else {
-			require.Len(t, toks, 65)
+			require.Len(t, toks, 66)
 		}
 		require.NotNil(t, qd)
 		require.Equal(t, qd.qtype, qt)
@@ -91,7 +91,7 @@ func TestQueryTokensPolygon(t *testing.T) {
 
 func TestQueryTokensPolygonError(t *testing.T) {
 	data := formData(t, "testdata/zip.json")
-	qtypes := []QueryType{QueryTypeNear, QueryTypeContains}
+	qtypes := []QueryType{QueryTypeNear}
 	for _, qt := range qtypes {
 		_, _, err := queryTokens(qt, data, 0.0)
 		require.Error(t, err)
@@ -257,8 +257,19 @@ func TestMatchesFilterIntersectsPolygon(t *testing.T) {
 		{{-120, 35}, {-121, 35}, {-121, 36}, {-120, 36}, {-120, 35}},
 	})
 	require.False(t, qd.MatchesFilter(poly))
-}
 
+	// These two polygons don't intersect.
+	polyOut := geom.NewPolygon(geom.XY).MustSetCoords([][]geom.Coord{
+		{{-122.4989104270935, 37.736953437345356}, {-122.50504732131958, 37.729096212099975}, {-122.49515533447264, 37.732049133202324}, {-122.4989104270935, 37.736953437345356}},
+	})
+
+	poly2 := geom.NewPolygon(geom.XY).MustSetCoords([][]geom.Coord{
+		{{-122.5033039, 37.7334601}, {-122.503128, 37.7335189}, {-122.5031222, 37.7335205}, {-122.5030813, 37.7335868}, {-122.5031511, 37.73359}, {-122.5031933, 37.7335916}, {-122.5032228, 37.7336022}, {-122.5032697, 37.7335937}, {-122.5033194, 37.7335874}, {-122.5033723, 37.7335518}, {-122.503369, 37.7335068}, {-122.5033462, 37.7334474}, {-122.5033039, 37.7334601}},
+	})
+	data = formDataPolygon(t, polyOut)
+	_, qd, err = queryTokens(QueryTypeIntersects, data, 0.0)
+	require.False(t, qd.MatchesFilter(poly2))
+}
 func TestMatchesFilterNearPoint(t *testing.T) {
 	p := geom.NewPoint(geom.XY).MustSetCoords(geom.Coord{-122.082506, 37.4249518})
 	data := formDataPoint(t, p)

types/s2.go

@@ -51,7 +51,7 @@ func (l loopRegion) edgesCross(c s2.Cell) bool {
 func (l loopRegion) edgesCrossPoints(pts []s2.Point) bool {
 	n := len(pts)
 	for i := 0; i < n; i++ {
-		crosser := s2.NewChainEdgeCrosser(pts[i], pts[(i+1)%n], pts[0])
+		crosser := s2.NewChainEdgeCrosser(pts[i], pts[(i+1)%n], l.Vertex(0))
 		for i := 1; i <= l.NumEdges(); i++ { // add vertex 0 twice as it is a closed loop
 			if crosser.EdgeOrVertexChainCrossing(l.Vertex(i)) {
 				return true

types/s2index_test.go

@@ -149,7 +149,7 @@ func TestKeyGeneratorPolygon(t *testing.T) {
 
 	keys, err := IndexGeoTokens(g)
 	require.NoError(t, err)
-	require.Len(t, keys, 65)
+	require.Len(t, keys, 66)
 }
 
 func testCover(file string, max int) {