fix(face): Ensure fast hole-merging method preserves first vertex

I forgot that I use this first vertex to track the history of the geometry in other parts of the library.

I'm also adding an acknowledgements section to the Readme as there are a lot of awesome MIT projects we used to build the library.

README.md

@@ -8,105 +8,143 @@
 
 # ladybug-geometry
 
-Ladybug geometry is a Python library that houses geometry objects used throughout the
-Ladybug Tools core libraries.
+Ladybug geometry is a Python library that houses geometry objects and geometry
+computations methods used throughout the Ladybug Tools core libraries.
+
+The library is designed to work with a wide range of Python environments and
+it returns consistent results between them (cPython 2 and 3, IronPython 2).
 
 ## Installation
 
 `pip install -U ladybug-geometry`
 
 ## [API Documentation](https://www.ladybug.tools/ladybug-geometry/docs/)
 
-## Local Development
-
-1. Clone this repo locally
-```console
-git clone [email protected]:ladybug-tools/ladybug-geometry.git
-
-# or
-
-git clone https://github.com/ladybug-tools/ladybug-geometry.git
-```
-
-2. Install dependencies:
-```console
-cd ladybug-geometry
-pip install -r dev-requirements.txt
-pip install -r requirements.txt
-```
-
-3. Run Tests:
-```console
-python -m pytests tests/
-```
-
-4. Generate Documentation:
-```console
-sphinx-apidoc -f -e -d 4 -o ./docs ./ladybug_geometry
-sphinx-build -b html ./docs ./docs/_build/docs
-```
-
 ## Currently Supported Capabilities of this Library
 
-- Vector Math (Dot, Cross, Angle, Normalize)
+- Perform Vector Math (Dot, Cross, Angle, Normalize)
 - Calculate Bounding Box for any Geometry (Min, Max, Center)
-- Compute Area + Perimeter of Planar Geometry
+- Subdivide Lines and Arcs
+- Compute Perimeter and Area of Planar Geometry
 - Check Concavity and Clockwise Ordering of 2D Geometry
 - Triangulate Planar Geometry
 - Compute Mesh Face Areas, Centroids, and Normals
 - Move Any Geometry
 - Rotate Any Geometry Around an Axis
 - Mirror (Reflect) Any Geometry Over a Plane
 - Scale Any Geometry from a Base Point
-- Is 2D Point Inside 2D Polygon
-- Compute Pole of Inaccessibility for any 2D Polygon
-- 2D Polygon Boolean Operations (Union, Intersection, Difference)
-- Intersect 2D Colinear Polygon Segments with one Another (for matching lengths)
+- Check if a 2D Point Inside 2D Polygon
+- Compute [Pole of Inaccessibility](https://en.wikipedia.org/wiki/Pole_of_inaccessibility) for any 2D Polygon
+- Perform 2D Polygon Boolean Operations (Union, Intersection, Difference)
+- Intersect Colinear 2D Polygon Segments with one Another (for matching lengths)
 - Join Line Segments into Polylines
-- 3D Face Plane and Normal Calculation from Vertices
-- 3D Face Intersection with a Ray or Line
-- Quad Mesh Grid Generation from a 3D Face
-- Sub-faces Based on Ratio with a Face (used for window generation)
-- Contours and Contour Fins from a Face (used to generate louvers, fins and overhangs)
+- Calculate 3D Face Plane and Normal from Vertices
+- Compute 3D Face Intersection with a Ray or Line
+- Generate a Quad Mesh Grid from a 3D Face
+- Generate Sub-faces Based on Ratio with a Face (used for window generation)
+- Generate Contours and Contour Fins from a Face (used to generate louvers, fins and overhangs)
 - Split 3D Coplanar Faces with one Another (for matching areas)
-- Solve Adjacencies by Matching Face Geometries
-- Join Faces into Polyfaces
+- Solve Adjacencies by Matching 3D Face Geometries
+- Join 3D Faces into 3D Polyfaces
 - Check if a 3D PolyFace is a Closed Solid
-- Ensure All Faces of a Solid PolyFace Point Outwards
+- Ensure All Faces of a Solid 3D PolyFace Point Outwards
+- Compute the Volume of a Closed 3D Polyface
 - Check if a Point is Inside a Closed 3D Polyface
 
 ## Officially Unsupported Capabilities for which One Must Rely on CAD Interfaces
 
-- Conversion of Curved Surfaces to Planar Surfaces (including both single curvature and double curvature)
+- Conversion of Curved 3D Surfaces to Planar 3D Faces
 - Fancier Meshing (eg. gridded meshing that completely fills the base surface)
 - Solid Boolean Unions (this should not be needed for anything in Ladybug Tools)
 
+## Acknowledgements
+
+This library was built by combining capabilities of several different open-source
+(MIT Licensed) projects, establishing a set of standardized geometry objects that
+allowed them all to talk to one another, and adding several other capabilities
+with new code. We as a community owe a huge amount of thanks to the open projects
+that provided many of the starting capabilities of this package and we are indebted
+to the developers who made their work under an MIT license for the betterment of
+geometry computation everywhere. Where possible, you will find detailed lists of
+references in the docstrings of source code. A summary of the key packages that
+were used to build this library are as follows:
+
+- [euclid](https://pypi.org/project/euclid/)
+- [earcut](https://github.com/mapbox/earcut) and [earcut-python](https://github.com/joshuaskelly/earcut-python)
+- [polybooljs](https://github.com/velipso/polybooljs) and [pypolybool](https://github.com/KaivnD/pypolybool)
+- [polylabel](https://github.com/Twista/python-polylabel)
+- [pySTL](https://github.com/proverbialsunrise/pySTL)
+- A countless number of [StackOverflow](https://stackoverflow.com/) experts who answered various geometry questions
+- A countless number of [Wikipedia](https://www.wikipedia.org/) authors who described various geometry algorithms
+
 ## Reasons for this Library
 
-We initially debated whether geometry computation should be placed largely on the CAD plugins or
-whether it should be included in the core.  As we developed the core libraries out, it became clear
-that there are large advantages to having it in the core (ie. cross compatibility between
-the CAD plugins, ability to process more inputs from command line, and shear speed
-since the CAD libraries are made to address many more geometric use cases than are typically needed).
-So we have decided to include geometry computation as part of the Ladybug Tools core.
+We initially debated whether the burden of geometry computation should be placed largely
+on the CAD environments in which Ladybug Tools operates or whether it should be included
+in a dedicated core Python library like this one.
+
+As we developed the core libraries, it became clear that there are large advantages
+to having it in the core including:
+
+- Standardized compatibility of geometry between different CAD plugins (eg. Rhino, Revit) and simulation engines + file formats (eg. E+, Radiance, gbXML).
+- The ability to perform geometry operations from the CLI of the core libraries without the need for any CAD software.
+- Improved performance given that a dedicated library could be tailored to the geometric use cases of Ladybug Tools.
+- Reliability and maintain-ability in the face of changes to CAD environments and changing Python conventions.
 
-We looked into using other geometry computation libraries for the core including:
+The first and last items above proved to be particularly important and so the
+decision was made that the Ladybug Tools core libraries would have its own
+geometry library that was distinct from CAD plugins.
+
+Before committing to write our own library, we looked into using or tweaking other
+comprehensive open source geometry libraries for the core including:
 
 - [Rhino3dm](https://github.com/mcneel/rhino3dm)
 - [Blender API (bpy)](https://docs.blender.org/api/current/)
+- [Boost Geometry](https://www.boost.org/doc/libs/1_78_0/libs/geometry/doc/html/index.html)
 - [Topologic](https://topologic.app/Software/)
 
-However, Rhino3dm lacks basic types of computation that is needed in the core (like generating a
-grid of points from a surface).
-Furthermore, Blender library only works in Python3 and this would break our workflows for the
-Grasshopper and Dynamo plugins, where rely on IronPython.
-Topologic seems to have many things that we need but it appears that it has C dependencies, making
-it unusable from IronPython.  Furthermore, its dual license may create some difficulties for certain
-use cases of Ladybug Tools.
-
-After considering it further, we realized that many of the calculations that we need can be done
-fairly easily as long as the geometry is planar.  Since all of the geometry going to the engines (Radiance, E+)
-is eventually converted to a planar format anyway, we made the decision that the core libraries will support
-certain basic types of geometry computation for planar objects only.  We planned to do this by taking the
-most relevant parts of existing open source geometry libraries, including [euclid](https://pypi.org/project/euclid/)
-and OpenStudio. Thus this repository was born!
+However, Rhino3dm lacks basic types of computation that would needed in the core (like generating
+a grid of points from a surface). The Blender library had many capabilities that we needed but
+it only works in Python3 and this could break certain CAD workflows that rely on IronPython.
+Boost Geometry (the geometry library used by the OpenStudio SDK) also had a lot of
+functionality but it clearly has C dependencies, making it unusable from IronPython.
+Lastly, Topologic also appeared to have C dependencies, though the more relevant issue was
+that its dual license could create challenges for certain use cases of Ladybug Tools.
+
+After considering the situation further, we realized that many of the capabilities that
+we needed could be achieved by building off the work of various open source MIT-licensed
+projects as long as we committed to using planar geometry. Since all of the geometry
+ultimately going to the engines (Radiance, E+) is planar format anyway, we made
+the decision that the core libraries will primarily support planar objects with
+very limited support for Arcs, Circles, Spheres, Cylinders and Cones.
+
+Thus this repository was born!
+
+## Local Development
+
+1. Clone this repo locally
+```console
+git clone [email protected]:ladybug-tools/ladybug-geometry.git
+
+# or
+
+git clone https://github.com/ladybug-tools/ladybug-geometry.git
+```
+
+2. Install dependencies:
+```console
+cd ladybug-geometry
+pip install -r dev-requirements.txt
+pip install -r requirements.txt
+```
+
+3. Run Tests:
+```console
+python -m pytests tests/
+```
+
+4. Generate Documentation:
+```console
+sphinx-apidoc -f -e -d 4 -o ./docs ./ladybug_geometry
+sphinx-build -b html ./docs ./docs/_build/docs
+```

ladybug_geometry/geometry2d/polygon.py

@@ -276,10 +276,18 @@ def from_shape_with_holes_fast(cls, boundary, holes):
         start_i = outer_node.i
         vertices = [Point2D(outer_node.x, outer_node.y)]
         node = outer_node.next
+        node_counter, orig_start_i = 0, 0
         while node.i != start_i:
             vertices.append(Point2D(node.x, node.y))
+            node_counter += 1
+            if node.i == 0:
+                orig_start_i = node_counter
             node = node.next
 
+        # ensure that the starting vertex is the same as the input boundary
+        vertices = vertices[orig_start_i:] + vertices[:orig_start_i]
+        vertices[0] = boundary[0]  # this avoids issues of floating point tolerance
+
         # return the polygon with some properties set based on what we know
         _new_poly = cls(vertices)
         _new_poly._is_clockwise = bound_direction

ladybug_geometry/geometry3d/face.py

@@ -90,7 +90,7 @@ class Face3D(Base2DIn3D):
                  '_boundary_polygon2d', '_hole_polygon2d',
                  '_perimeter', '_area', '_centroid',
                  '_is_convex', '_is_self_intersecting')
-    HOLE_VERTEX_THRESHOLD = 100  # threshold at which faster hole merging method is used
+    HOLE_VERTEX_THRESHOLD = 400  # threshold at which faster hole merging method is used
 
     def __init__(self, boundary, plane=None, holes=None, enforce_right_hand=True):
         """Initialize Face3D."""

ladybug_geometry/intersection2d.py

@@ -1,7 +1,8 @@
 # coding=utf-8
 """Utility functions for computing intersections between geometry in 2D space.
 
-Taken mostly from the euclid.py package.
+Taken mostly from the euclid package available at
+https://pypi.org/project/euclid/
 """
 from __future__ import division
 

ladybug_geometry/intersection3d.py

@@ -1,7 +1,8 @@
 # coding=utf-8
 """Utility functions for computing intersections between geometry in 3D space.
 
-Taken mostly from the euclid.py package.
+Taken mostly from the euclid package available at
+https://pypi.org/project/euclid/
 """
 from __future__ import division
 

tests/face3d_test.py

@@ -313,6 +313,23 @@ def test_face3d_init_from_shape_with_holes():
     assert face.is_self_intersecting is False
 
 
+def test_face3d_shape_with_many_holes():
+    """Test Face3D from_shape_with_holes with a Face3D above the vertex threshold."""
+    geo_file = './tests/json/face_with_200_holes.json'
+    with open(geo_file, 'r') as fp:
+        geo_dict = json.load(fp)
+    face_geo = Face3D.from_dict(geo_dict)
+
+    v_count = len(face_geo.boundary)  # count the vertices for hole merging method
+    for h in face_geo.holes:
+        v_count += len(h)
+    assert v_count > face_geo.HOLE_VERTEX_THRESHOLD
+    assert len(face_geo.vertices) > v_count + len(face_geo.holes)
+
+    assert face_geo.boundary[0] == face_geo.vertices[0]
+    assert face_geo.area == pytest.approx(62.416884, rel=1e-4)
+
+
 def test_face3d_init_from_punched_geometry():
     """Test the initialization of Face3D from_shape_with_holes."""
     bound_pts = [Point3D(0, 0), Point3D(4, 0), Point3D(4, 4), Point3D(0, 4)]