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34 lines
818 B
34 lines
818 B
4 years ago
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import 'dart:math';
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import 'package:flutter/material.dart';
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class BackGroundClipper extends CustomClipper<Path> {
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///取值为 -1 ~ 1.0
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double moveFlag = 0;
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BackGroundClipper(this.moveFlag);
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@override
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Path getClip(Size size) {
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//创建 Path
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Path path = Path();
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//移动到点 P0点 也是曲线的起点
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path.lineTo(0, size.height * 0.2);
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//计算控制点 P1 的坐标
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double xCenter = size.width * 0.5 +
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(size.width * 0.6 + 1) * sin(moveFlag * pi);
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double yCenter = size.height * 0.2 + 69 * cos(moveFlag*pi);
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//构建 二阶贝塞尔曲线
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path.quadraticBezierTo(xCenter, yCenter, size.width, size.height * 0.2);
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path.lineTo(size.width, 0);
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return path;
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}
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@override
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bool shouldReclip(CustomClipper<Path> oldClipper) {
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return true;
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}
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}
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