geometry.py

import math

def points_within_dist(x1, y1, x2, y2, dist):
    return (x1-x2)*(x1-x2) + (y1-y2)*(y1-y2) <= dist*dist

def rotate_point(x, y, cx, cy, angle_deg):
    """Rotate point (x, y) around center (cx, cy) by angle in degrees (clockwise)."""
    angle_rad = math.radians(angle_deg)
    cos_a = math.cos(angle_rad)
    sin_a = math.sin(angle_rad)
    dx = x - cx
    dy = y - cy
    rx = cx + dx * cos_a - dy * sin_a
    ry = cy + dx * sin_a + dy * cos_a
    return rx, ry

def connection_point(x, y, width, height, angle_deg, conn_x, conn_y):
    """
    Compute location of the rotated connection point of a shape.

    Parameters:
        x, y, width, height: (unrotated) bounding box of the shape
        angle_deg: rotation in degrees (positive = clockwise)
        conn_y, conn_y: relative connection point (0 to 1)

    Returns:
        (x, y): absolute coordinates of rotated connection point
    """
    # compute unrotated connection point:
    px = x + conn_x * width
    py = y + conn_y * height
    # center of bounding box:
    cx = x + width / 2
    cy = y + height / 2
    return rotate_point(px, py, cx, cy, angle_deg)

def triangle_tip(x, y, width, height, angle_deg):
    """
    Compute location of the tip of unrotated right-pointing triangle after rotation,
    along with a "slack" distance within which a connection would be considered close enough.
    """
    # unrotated tip:
    ax = x + width
    ay = y + height / 2
    # center of bounding box
    cx = x + width / 2
    cy = y + height / 2
    return rotate_point(ax, ay, cx, cy, angle_deg), height / 16