Geometry Utility Functions

geometry.py

import math

from shapely.geometry import Point, LineString, Polygon, MultiPolygon


def create_rectangle(x, y, width, depth, angle):
    
    width_theta = math.radians(angle)
    width_x = width * math.cos(width_theta)
    width_y = width * math.sin(width_theta)

    depth_theta = math.radians(angle + 90)
    depth_x = depth * math.cos(depth_theta)
    depth_y = depth * math.sin(depth_theta)

    x0 = x
    y0 = y
    x1 = x + width_x
    y1 = y + width_y
    x2 = x + width_x + depth_x
    y2 = y + width_y + depth_y
    x3 = x + depth_x
    y3 = y + depth_y

    poly = Polygon([(x0, y0), (x1, y1), (x2, y2), (x3, y3)])

    return poly


def create_point(x, y, angle, distance):

    t = math.radians(angle)
    
    new_x = x + distance * math.cos(t)
    new_y = y + distance * math.sin(t)
    
    return Point(new_x, new_y)


def find_angle(a, b, c):
    # c |   / a
    #   |  /
    #   | /
    # b |/
    
    ba = (a.y - b.y, a.x - b.x)
    bc = (c.y - b.y, c.x - b.x)
    
    ang = math.degrees(math.atan2(bc[0], bc[1]) - math.atan2(ba[0], ba[1]))
    
    ang = ang + 360 if ang < 0 else ang
    
    return ang


def xy(ring):
    r_xs, r_ys = list(), list()

    for pt in ring.coords:
        r_xs.append(pt[0])
        r_ys.append(pt[1])
    
    return r_xs, r_ys


def linestring_list_xy(lines):
    l_xs, l_ys = list(), list()
    
    for line in lines:
        xs, ys = xy(line)
        l_xs.append(xs)
        l_ys.append(ys)
    
    return l_xs, l_ys


def polygon_xy(poly):
    p_xs, p_ys = list(), list()

    x, y = xy(poly.exterior)
    p_xs.append(x)
    p_ys.append(y)

    for hole in poly.interiors:
        x, y = xy(hole)
        p_xs.append(x)
        p_ys.append(y)
    
    return p_xs, p_ys


def multipolygon_xy(geom):
    mp_xs, mp_ys = list(), list()
    
    mp = MultiPolygon([geom]) if type(geom) == Polygon else geom
    
    for poly in mp.geoms:
        p_xs, p_ys = polygon_xy(poly)
        mp_xs.append(p_xs)
        mp_ys.append(p_ys)

    return mp_xs, mp_ys


def multipolygon_list_xy(geoms):
    xs, ys = list(), list()
    
    for geom in geoms:
        mp_xs, mp_ys = multipolygon_xy(geom)
        xs.append(mp_xs)
        ys.append(mp_ys)
    
    return xs, ys


def point_list_xy(points):
    x, y = list(), list()
    
    for pt in points:
        x.append(pt.x)
        y.append(pt.y)
    
    return x, y


def create_slice_line(x, y, width, depth, angle, slices):
    
    buf_dist = 1
    slices = round(slices)

    s = create_point(x, y, angle - 90, buf_dist)
    
    pts = list()
    
    for i in range(slices - 1):
        p0 = pts[(i * 2) - 1] if len(pts) else s
        p1 = create_point(p0.x, p0.y, angle, width / slices)
        p2 = create_point(p1.x, p1.y, angle + (-90 if i % 2 else 90), depth + buf_dist * 2)
        
        pts.extend([p1, p2])
        
    l = LineString([(pt.x, pt.y) for pt in pts])
        
    return l