@phaserjs/phaser/geom/intersects/LineToCircle.js

Phaser 4

/**
 * @author       Richard Davey <rich@photonstorm.com>
 * @copyright    2020 Photon Storm Ltd.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */
import { CircleContains } from "../circle/CircleContains";
import { Vec2 } from "../../math/vec2/Vec2";
const tmp = new Vec2();
export function LineToCircle(line, circle, nearest) {
  if (!nearest) {
    nearest = tmp;
  }
  const { x1, y1, x2, y2 } = line;
  if (CircleContains(circle, x1, y1)) {
    nearest.set(x1, y1);
    return true;
  }
  if (CircleContains(circle, x2, y2)) {
    nearest.set(x2, y2);
    return true;
  }
  const dx = x2 - x1;
  const dy = y2 - y1;
  const lcx = circle.x - x1;
  const lcy = circle.y - y1;
  const dLen2 = dx * dx + dy * dy;
  let px = dx;
  let py = dy;
  if (dLen2 > 0) {
    const dp = (lcx * dx + lcy * dy) / dLen2;
    px *= dp;
    py *= dp;
  }
  nearest.set(x1 + px, y1 + py);
  const pLen2 = px * px + py * py;
  return pLen2 <= dLen2 && px * dx + py * dy >= 0 && CircleContains(circle, nearest.x, nearest.y);
}