forked from lxm_flutter/FlutterUnit
26 lines
790 B
Dart
26 lines
790 B
Dart
import 'dart:math';
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import 'package:flutter/cupertino.dart';
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class Pather {
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Pather._();
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static Pather create = Pather._();
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final Path _path = Path();
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Path nStarPath(int num, double R, double r, {dx = 0, dy = 0}) {
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_path.reset();//重置路径
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double perRad = 2 * pi / num;//每份的角度
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double radA = perRad / 2 / 2;//a角
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double radB = 2 * pi / (num - 1) / 2 - radA / 2 + radA;//起始b角
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_path.moveTo(cos(radA) * R + dx, -sin(radA) * R + dy);//移动到起点
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for (int i = 0; i < num; i++) {//循环生成点，路径连至
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_path.lineTo(cos(radA + perRad * i) * R + dx, -sin(radA + perRad * i) * R + dy);
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_path.lineTo(cos(radB + perRad * i) * r + dx, -sin(radB + perRad * i) * r + dy);
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}
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_path.close();
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return _path;
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}
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}
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