From c3ca0b65bc7a051429a7a5cce38c84e9983dbb0b Mon Sep 17 00:00:00 2001
From: Michael Fogleman <fogleman@gmail.com>
Date: Mon, 26 Feb 2018 21:42:49 -0500
Subject: [PATCH] shapely <-> paths

---
 axi/__init__.py |  2 ++
 axi/paths.py    | 23 +++++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/axi/__init__.py b/axi/__init__.py
index c16f76a..d01b1ea 100644
--- a/axi/__init__.py
+++ b/axi/__init__.py
@@ -9,7 +9,9 @@ from .paths import (
     load_paths,
     path_length,
     paths_length,
+    paths_to_shapely,
     quadratic_path,
+    shapely_to_paths,
     simplify_path,
     simplify_paths,
     sort_paths,
diff --git a/axi/paths.py b/axi/paths.py
index 3086bc0..d7508d1 100644
--- a/axi/paths.py
+++ b/axi/paths.py
@@ -156,3 +156,26 @@ def expand_quadratics(path):
         else:
             raise Exception('invalid point: %r' % point)
     return result
+
+def paths_to_shapely(paths):
+    # TODO: Polygons for closed paths?
+    return geometry.MultiLineString(paths)
+
+def shapely_to_paths(g):
+    if isinstance(g, geometry.Point):
+        return []
+    elif isinstance(g, geometry.LineString):
+        return [list(g.coords)]
+    elif isinstance(g, (geometry.MultiPoint, geometry.MultiLineString, geometry.MultiPolygon, geometry.collection.GeometryCollection)):
+        paths = []
+        for x in g:
+            paths.extend(shapely_to_paths(x))
+        return paths
+    elif isinstance(g, geometry.Polygon):
+        paths = []
+        paths.append(list(g.exterior.coords))
+        for interior in g.interiors:
+            paths.extend(shapely_to_paths(interior))
+        return paths
+    else:
+        raise Exception('unhandled shapely geometry: %s' % type(g))