From 34cf674fa08cfa8f11ec1722627693f474911a7b Mon Sep 17 00:00:00 2001
From: Oliver Tonnhofer <olt@bogosoft.com>
Date: Tue, 26 Nov 2013 09:47:00 +0100
Subject: [PATCH] read geojson with z-values

---
 geom/geojson/geojson.go      |  4 ++--
 geom/geojson/geojson_test.go | 16 ++++++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/geom/geojson/geojson.go b/geom/geojson/geojson.go
index 6c01298..5518cb2 100644
--- a/geom/geojson/geojson.go
+++ b/geom/geojson/geojson.go
@@ -27,8 +27,8 @@ type point struct {
 
 func newPointFromCoords(coords []interface{}) (point, error) {
 	p := point{}
-	if len(coords) != 2 {
-		return p, errors.New("point list length not 2")
+	if len(coords) != 2 && len(coords) != 3 {
+		return p, errors.New("point list length not 2 or 3")
 	}
 	var ok bool
 	p.long, ok = coords[0].(float64)
diff --git a/geom/geojson/geojson_test.go b/geom/geojson/geojson_test.go
index 30f09f1..6b972c2 100644
--- a/geom/geojson/geojson_test.go
+++ b/geom/geojson/geojson_test.go
@@ -22,6 +22,22 @@ func TestParsePolygon(t *testing.T) {
 		t.Fatal(geoms[0].Area())
 	}
 
+	// ignore z values
+	r = bytes.NewBufferString(`{"type": "Polygon", "coordinates": [[[0, 0, 0], [10, 0, 0], [10, 10, 0], [0, 10, 0], [0, 0, 0]]]}`)
+	geoms, err = ParseGeoJson(r)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(geoms) != 1 {
+		t.Fatal(geoms)
+	}
+
+	if math.Abs(geoms[0].Area()-100) > 0.00001 {
+		t.Fatal(geoms[0].Area())
+	}
+
 	r = bytes.NewBufferString(`{"type": "Polygon", "coordinates": [[[0, 0], [10, 0], [10, 10], [0, 10], [0, 0]], [[5, 5], [6, 5], [6, 6], [5, 6], [5, 5]]]}`)
 	geoms, err = ParseGeoJson(r)