--- a/pkg/wkb/data.go	Sat Aug 06 00:46:21 2022 +0200
+++ b/pkg/wkb/data.go	Sat Aug 06 02:09:57 2022 +0200
@@ -21,15 +21,20 @@
 )
 
 type (
+	// PointGeom is a 2D point,
 	PointGeom struct {
 		X float64
 		Y float64
 	}
-	LinearRingGeom   []PointGeom
-	PolygonGeom      []LinearRingGeom
+	// LinearRingGeom is a ring of points.
+	LinearRingGeom []PointGeom
+	// PolygonGeom is a polygon.
+	PolygonGeom []LinearRingGeom
+	// MultiPolygonGeom is a multi polygon.
 	MultiPolygonGeom []PolygonGeom
 )
 
+// AsWKB serializes a multi polygon as WKB.
 func (mpg MultiPolygonGeom) AsWKB() []byte {
 
 	size := 1 + 4 + 4
@@ -65,6 +70,7 @@
 	return buf.Bytes()
 }
 
+// FromWKB deserializes a multi polygon from WKB.
 func (mpg *MultiPolygonGeom) FromWKB(data []byte) error {
 	r := bytes.NewReader(data)
 
@@ -152,6 +158,7 @@
 	return nil
 }
 
+// CCW tells if the ring is oriented counter clock wise.
 func (lr LinearRingGeom) CCW() bool {
 	var sum float64
 	for i, v1 := range lr {
@@ -161,6 +168,7 @@
 	return sum > 0
 }
 
+// Reverse changes the orientation of the ring.
 func (lr LinearRingGeom) Reverse() {
 	for i, j := 0, len(lr)-1; i < j; i, j = i+1, j-1 {
 		lr[i], lr[j] = lr[j], lr[i]