Source code for arcade.geometry

Functions for calculating geometry.

import math

from shapely import speedups  # type: ignore
from shapely.geometry import Polygon, Point  # type: ignore
from typing import List

from arcade import PointList



[docs]def are_polygons_intersecting(poly_a: PointList, poly_b: PointList) -> bool: """ Return True if two polygons intersect. :param PointList poly_a: List of points that define the first polygon. :param PointList poly_b: List of points that define the second polygon. :Returns: True or false depending if polygons intersect :rtype bool: """ shapely_polygon_a = Polygon(poly_a) shapely_polygon_b = Polygon(poly_b) r2 = False r1 = shapely_polygon_a.intersects(shapely_polygon_b) if r1: r2 = shapely_polygon_a.touches(shapely_polygon_b) return r1 and not r2
[docs]def is_point_in_polygon(x: float, y: float, polygon_point_list) -> bool: """ Use ray-tracing to see if point is inside a polygon Args: x: y: polygon_point_list: Returns: bool """ shapely_point = Point(x, y) shapely_polygon = Polygon(polygon_point_list) return shapely_polygon.contains(shapely_point)
[docs]def get_distance(x1: float, y1: float, x2: float, y2: float): """ Get the distance between two points. """ return math.hypot(x1 - x2, y1 - y2)
[docs]def clamp(a, low, high): """ Clamp a number between a range. """ if a > high: return high elif a < low: return low else: return a
[docs]def rotate_point(x: float, y: float, cx: float, cy: float, angle_degrees: float) -> List[float]: """ Rotate a point around a center. :param x: x value of the point you want to rotate :param y: y value of the point you want to rotate :param cx: x value of the center point you want to rotate around :param cy: y value of the center point you want to rotate around :param angle_degrees: Angle, in degrees, to rotate :return: Return rotated (x, y) pair :rtype: (float, float) """ temp_x = x - cx temp_y = y - cy # now apply rotation angle_radians = math.radians(angle_degrees) cos_angle = math.cos(angle_radians) sin_angle = math.sin(angle_radians) rotated_x = temp_x * cos_angle - temp_y * sin_angle rotated_y = temp_x * sin_angle + temp_y * cos_angle # translate back rounding_precision = 2 x = round(rotated_x + cx, rounding_precision) y = round(rotated_y + cy, rounding_precision) return [x, y]