58 lines
1.7 KiB
TypeScript
58 lines
1.7 KiB
TypeScript
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import { pointAtSegments, angleAtSegments, distanceAtSegment, lengthOfSegment } from './segments';
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import polyline from './polyline';
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import { PointTuple } from './types';
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function getAllPoints(points: PointTuple[]) {
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const tmp = points.slice(0);
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if (points.length) {
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tmp.push(points[0]);
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}
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return tmp;
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}
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export default {
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/**
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* 计算多边形的包围盒
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* @param {array} points 点的集合 [x,y] 的形式
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* @return {object} 包围盒
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*/
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box(points: PointTuple[]) {
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return polyline.box(points);
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},
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/**
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* 计算多边形的长度
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* @param {array} points 点的集合 [x,y] 的形式
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* @return {object} 多边形边的长度
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*/
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length(points: PointTuple[]) {
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return lengthOfSegment(getAllPoints(points));
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},
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/**
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* 根据比例获取多边形的点
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* @param {array} points 点的集合 [x,y] 的形式
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* @param {number} t 在多边形的长度上的比例
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* @return {object} 根据比例值计算出来的点
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*/
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pointAt(points: PointTuple[], t: number) {
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return pointAtSegments(getAllPoints(points), t);
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},
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/**
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* 指定点到多边形的距离
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* @param {array} points 点的集合 [x,y] 的形式
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* @param {number} x 指定点的 x
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* @param {number} y 指定点的 y
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* @return {number} 点到多边形的距离
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*/
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pointDistance(points: PointTuple[], x: number, y: number) {
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return distanceAtSegment(getAllPoints(points), x, y);
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},
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/**
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* 根据比例获取多边形的切线角度
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* @param {array} points 点的集合 [x,y] 的形式
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* @param {number} t 在多边形的长度上的比例
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* @return {object} 根据比例值计算出来的角度
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*/
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tangentAngle(points: PointTuple[], t: number) {
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return angleAtSegments(getAllPoints(points), t);
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},
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};
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