kopia lustrzana https://github.com/Tldraw/Tldraw
78 wiersze
1.8 KiB
TypeScript
78 wiersze
1.8 KiB
TypeScript
import { Vec } from '../Vec'
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import { Edge2d } from './Edge2d'
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import { Geometry2d, Geometry2dOptions } from './Geometry2d'
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/** @public */
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export class Polyline2d extends Geometry2d {
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points: Vec[]
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constructor(config: Omit<Geometry2dOptions, 'isFilled' | 'isClosed'> & { points: Vec[] }) {
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super({ isClosed: false, isFilled: false, ...config })
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const { points } = config
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this.points = points
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}
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_segments?: Edge2d[]
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// eslint-disable-next-line no-restricted-syntax
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get segments() {
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if (!this._segments) {
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this._segments = []
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const { vertices } = this
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for (let i = 0, n = vertices.length - 1; i < n; i++) {
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const start = vertices[i]
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const end = vertices[i + 1]
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this._segments.push(new Edge2d({ start, end }))
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}
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if (this.isClosed) {
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this._segments.push(new Edge2d({ start: vertices[vertices.length - 1], end: vertices[0] }))
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}
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}
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return this._segments
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}
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_length?: number
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// eslint-disable-next-line no-restricted-syntax
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get length() {
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if (!this._length) {
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this._length = this.segments.reduce((acc, segment) => acc + segment.length, 0)
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}
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return this._length
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}
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getVertices() {
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return this.points
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}
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nearestPoint(A: Vec): Vec {
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const { segments } = this
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let nearest = this.points[0]
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let dist = Infinity
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let p: Vec // current point on segment
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let d: number // distance from A to p
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for (let i = 0; i < segments.length; i++) {
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p = segments[i].nearestPoint(A)
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d = Vec.Dist2(p, A)
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if (d < dist) {
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nearest = p
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dist = d
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}
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}
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if (!nearest) throw Error('nearest point not found')
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return nearest
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}
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hitTestLineSegment(A: Vec, B: Vec, distance = 0): boolean {
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const { segments } = this
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for (let i = 0, n = segments.length; i < n; i++) {
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if (segments[i].hitTestLineSegment(A, B, distance)) {
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return true
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}
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}
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return false
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}
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}
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