Optimize point in ring

go.mod

@@ -28,7 +28,7 @@ require (
 	github.com/tidwall/buntdb v1.1.0
 	github.com/tidwall/cities v0.0.0-20190730194520-dbe1ae0b862c // indirect
 	github.com/tidwall/geoindex v1.1.0
-	github.com/tidwall/geojson v1.1.12
+	github.com/tidwall/geojson v1.1.13
 	github.com/tidwall/gjson v1.3.2
 	github.com/tidwall/grect v0.0.0-20161006141115-ba9a043346eb // indirect
 	github.com/tidwall/lotsa v0.0.0-20180225195211-a03631ac7f1c // indirect

go.sum

@@ -67,6 +67,8 @@ github.com/tidwall/geojson v1.1.10 h1:ALzsrTn62pq65DudSQpYDjjCUaq6dP1XQm51GVYgJy
 github.com/tidwall/geojson v1.1.10/go.mod h1:tBjfxeALRFLc25LLpjtWzy2nIrNmW1ze1EAhLtd8+QQ=
 github.com/tidwall/geojson v1.1.12 h1:Ol83kqH2zeYJHP16xteZtr8VRukIXeF/TqVvJodM41M=
 github.com/tidwall/geojson v1.1.12/go.mod h1:tBjfxeALRFLc25LLpjtWzy2nIrNmW1ze1EAhLtd8+QQ=
+github.com/tidwall/geojson v1.1.13 h1:P7f58SrQgyb9k3HjKStRLug4i/0U+1MJ00f/4Z92wcM=
+github.com/tidwall/geojson v1.1.13/go.mod h1:tBjfxeALRFLc25LLpjtWzy2nIrNmW1ze1EAhLtd8+QQ=
 github.com/tidwall/gjson v1.3.2 h1:+7p3qQFaH3fOMXAJSrdZwGKcOO/lYdGS0HqGhPqDdTI=
 github.com/tidwall/gjson v1.3.2/go.mod h1:P256ACg0Mn+j1RXIDXoss50DeIABTYK1PULOJHhxOls=
 github.com/tidwall/grect v0.0.0-20161006141115-ba9a043346eb h1:5NSYaAdrnblKByzd7XByQEJVT8+9v0W/tIY0Oo4OwrE=

vendor/github.com/tidwall/geojson/geometry/ring.go

@@ -24,30 +24,59 @@ type ringResult struct {
 }
 
 func ringContainsPoint(ring Ring, point Point, allowOnEdge bool) ringResult {
-	// println("A")
-	var idx = -1
-	// find all intersecting segments on the y-axis
 	var in bool
+	var idx int
+	rect := Rect{Point{math.Inf(-1), point.Y}, Point{math.Inf(+1), point.Y}}
+	if bs, ok := ring.(*baseSeries); ok {
+		in, idx = ringContainsPointBaseSeries(rect, bs, point, allowOnEdge)
+	} else {
+		in, idx = ringContainsPointGeneric(rect, ring, point, allowOnEdge)
+	}
+	return ringResult{hit: in, idx: idx}
+}
+
+func containsPointSearcher(point Point, allowOnEdge bool, idx *int, in *bool, seg Segment, index int) bool {
+	// perform a raycast operation on the segments
+	res := seg.Raycast(point)
+	if res.On {
+		*in = allowOnEdge
+		*idx = index
+		return false
+	}
+	if res.In {
+		*in = !*in
+	}
+	return true
+}
+
+// NOTE: Although it may seem that ringContainsPointBaseSeries and ringContainsPointGeneric
+// are the same, they are not. Because the type of the `ring` argument is known in
+// ringContainsPointBaseSeries, the compiler can prove that the closure passed to
+// ring.Search does not escape, and hence save us 3 heap allocations and ~6% runtime.
+
+func ringContainsPointBaseSeries(rect Rect, ring *baseSeries, point Point, allowOnEdge bool) (bool, int) {
+	var idx = -1
+	var in bool
+
 	ring.Search(
-		Rect{Point{math.Inf(-1), point.Y}, Point{math.Inf(+1), point.Y}},
+		rect,
 		func(seg Segment, index int) bool {
-			// fmt.Printf("%v %v\n", point, seg)
-			// perform a raycast operation on the segments
-			res := seg.Raycast(point)
-			if res.On {
-				// println(1)
-				in = allowOnEdge
-				idx = index
-				return false
-			}
-			if res.In {
-				// println(2)
-				in = !in
-			}
-			return true
+			return containsPointSearcher(point, allowOnEdge, &idx, &in, seg, index)
 		},
 	)
-	return ringResult{hit: in, idx: idx}
+	return in, idx
+}
+
+func ringContainsPointGeneric(rect Rect, ring Ring, point Point, allowOnEdge bool) (bool, int) {
+	var idx = -1
+	var in bool
+	ring.Search(
+		rect,
+		func(seg Segment, index int) bool {
+			return containsPointSearcher(point, allowOnEdge, &idx, &in, seg, index)
+		},
+	)
+	return in, idx
 }
 
 func ringIntersectsPoint(ring Ring, point Point, allowOnEdge bool) ringResult {

vendor/modules.txt

@@ -81,7 +81,7 @@ github.com/tidwall/buntdb
 # github.com/tidwall/geoindex v1.1.0
 github.com/tidwall/geoindex
 github.com/tidwall/geoindex/child
-# github.com/tidwall/geojson v1.1.12
+# github.com/tidwall/geojson v1.1.13
 github.com/tidwall/geojson
 github.com/tidwall/geojson/geo
 github.com/tidwall/geojson/geometry