rhinopython script to convert curves to a geojson

curves_to_geojson.py

import rhinoscriptsyntax as rs
import Rhino.Geometry.Point3d as Point
import json

# creates network from curves

# curves that are not ```Line```s will be divided
CURVE_DIVISION = 4
# points that are separted less then this value will
# be treated as one point 
TOLERANCE = 1;

# bbox = rs.GetRectangle(1)
# minx =  100000
# maxx = -100000
# miny =  100000
# maxy = -100000

# for p in bbox:
#     minx = min(minx, p.X)
#     maxx = max(maxx, p.X)
#     miny = min(miny, p.Y)
#     maxy = max(maxy, p.Y)

minx = 0
maxx = 2128
miny = 0
maxy = 1330


l = rs.GetLayer()

isoneway = rs.GetBoolean("is it?", ("Oneway", "no", "yes"), (False)
)[0]

crvs = list(filter(lambda x: rs.IsCurve(x), rs.ObjectsByLayer(l)))
points = []

# returns the index of the point,
# addes the point to the array if it's unique
def appendIfUnique(pts, p):
    for testP in pts:
        if testP.DistanceTo(p) < TOLERANCE:
            return (pts, testP)
    pts.append(p)
    return (pts, p)
    
def normalizePoint(p, minx=minx, maxx=maxx, miny=miny, maxy=maxy):
    nx = (p.X - minx) / (maxx - minx)
    ny = (p.Y - miny) / (maxy - miny)
    
    return Point(nx, ny, 0.0)

geojson = {}
geojson["type"] = "Feature Collection"
geojson["features"] = []

for c in crvs :
    jsonobj = {}
    jsonobj["type"] = "Feature"
    jsonobj["properties"] = {}
    jsonobj["properties"]["length"] = rs.CurveLength(c)
    jsonobj["geometry"] = {}
    jsonobj["geometry"]["type"] = "LineString"
    
    if isoneway :
        jsonobj["properties"]["oneway"] = True
    else :
        jsonobj["properties"]["oneway"] = False

    if rs.IsLine(c):
        points, st = appendIfUnique(points, rs.CurveStartPoint(c))
        points, en = appendIfUnique(points, rs.CurveEndPoint(c))
        
        st, en = [normalizePoint(e) for e in [st, en]]
        
        jsonobj["geometry"]["coordinates"] = [
          [st.X, st.Y],
          [en.X, en.Y]
        ]
        
    else:
        # it is not a line curve object
        curvepoints = rs.DivideCurve(c, CURVE_DIVISION)
        jsonobj["geometry"]["coordinates"] = [] 
        for p in curvepoints:
            points, p = appendIfUnique(points, p)
            p = normalizePoint(p)
            jsonobj["geometry"]["coordinates"].append([p.X, p.Y])
            
    geojson["features"].append(jsonobj)

jsonstr = json.dumps(geojson, indent = 4)

f = open("{}.geojson".format(l), "w")
f.writelines(jsonstr)
f.close()