https://github.com/stagas/find-shortest-path
Find shortest path between two nodes using A-star search.
https://github.com/stagas/find-shortest-path
a-star shortest-path
Last synced: 6 months ago
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Find shortest path between two nodes using A-star search.
- Host: GitHub
- URL: https://github.com/stagas/find-shortest-path
- Owner: stagas
- License: mit
- Created: 2022-06-03T17:47:04.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2022-07-30T15:50:40.000Z (about 3 years ago)
- Last Synced: 2025-03-14T02:39:23.267Z (7 months ago)
- Topics: a-star, shortest-path
- Language: TypeScript
- Homepage: https://stagas.github.io/find-shortest-path/example/web.html
- Size: 69.3 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
find-shortest-path 
Find shortest path between two nodes using A-star search.
npm i find-shortest-path
pnpm add find-shortest-path
yarn add find-shortest-path
## Examples
# web
- #
view source example/web.ts
```ts
import { Line, Point, Polygon, Rect } from 'geometrik'
import {
findShortestPath,
// findShortestPathBi,
Heuristics,
ShortestPath,
} from 'find-shortest-path'
const svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg')
const path = document.createElementNS('http://www.w3.org/2000/svg', 'path')
let ri = 2392
const rnd = () => Math.sin(++ri * 10e10 * Math.sin(ri * 10e10)) * 0.5 + 0.5
const size = Math.min(window.innerWidth / 2, window.innerHeight / 2)
const rects = Array.from({ length: 15 }, () => {
return new Rect(
rnd() * size + 50,
rnd() * size + 50,
rnd() * size / 3,
rnd() * size / 3
)
})
for (const rect of rects) {
rect.draw()
}
const step = 30
const a = new Rect(find-shortest-path.new Point(0, 0).gridRoundSelf(step), 10, 10)
const b = new Rect(find-shortest-path.new Point(size, size).gridRoundSelf(step), 150, 150)
const pa = a.topLeft
let pb = b.bottomRight.gridRound(step)
pa.draw()
pb.draw()
const big = Rect.combine([a, b]).zoomLinear(step * 4)
big.draw()
declare const console: Console & {
edit: (object: T, callback: (changed: T) => void) => void
}
const solve = () => {
const intersects = (a: Point, b: Point) => {
const line = new Line(a, b)
for (const rect of rects) {
if (line.intersectsRect(rect)) return true
}
return false
}
const acceptTolerance = 1 * step
const points = findShortestPath({
start: pa,
goal: pb,
hash: p => p.gridRound(step).toString(),
strategies: [
{
accept: (a, b) => !intersects(a, b) && a.manhattan(b) <= acceptTolerance,
distance: [Heuristics.Manhattan, 1.45],
heuristic: [Heuristics.Chebyshev, 10],
// distance: [Heuristics.Manhattan],
// heuristic: [Heuristics.Chebyshev, 50],
negativeHeap: true,
maxIterations: 30,
},
{
accept: (a, b) => !intersects(a, b) && a.manhattan(b) <= acceptTolerance,
// distance: [Heuristics.Manhattan, multipliers.distance],
// heuristic: [Heuristics.Chebyshev, multipliers.heuristic],
distance: [Heuristics.Manhattan, 0.8],
heuristic: [Heuristics.Euclidean, 10.65],
// distance: [Heuristics.Manhattan, 0.45],
// heuristic: [Heuristics.Euclidean, 20.65],
maxIterations: 30,
},
{
accept: (a, b) => a.manhattan(b) <= step * 1.5,
distance: [Heuristics.Manhattan],
heuristic: [Heuristics.Chebyshev, 50],
maxIterations: 300,
},
],
neighbors(p) {
return [
p.translate(+step, 0),
p.translate(0, +step),
p.translate(-step, 0),
p.translate(0, -step),
p.translate(+step, +step),
p.translate(+step, -step),
p.translate(-step, +step),
p.translate(-step, -step),
]
.filter(p => p.withinRect(big))
.filter(n => {
const line = new Line(p, n)
return rects.every(r => !line.intersectsRect(r))
})
},
})
return points
}
let points!: ShortestPath
for (let i = 50; i--;) {
points = solve()
if (!points.length) break
}
console.table(points.meta)
let followPointer = true
document.onclick = () => {
followPointer = !followPointer
}
if (points) {
svg.setAttribute('width', '' + window.innerWidth)
svg.setAttribute('height', '' + window.innerHeight)
path.setAttribute('stroke', '#fff')
path.setAttribute('stroke-width', '2')
path.setAttribute('d', Polygon.toSVGPath(points))
svg.appendChild(path)
document.body.appendChild(svg)
document.body.onpointermove = e => {
if (!followPointer) return
pb = new Point(e.pageX, e.pageY)
if (pb.withinRect(big)) {
for (const rect of rects) {
if (pb.withinRect(rect)) {
pb.set(pb.touchPoint(rect))
break
}
}
points = solve()
console.table(points.meta)
if (points.length > 2) {
path.setAttribute('d', Polygon.toSVGPath(points))
}
}
}
}
```
## API
# ShortestPath src/find-shortest-path.ts#L15
# meta src/find-shortest-path.ts#L16
ShortestPathMeta
Strategy src/find-shortest-path.ts#L26 # accept src/find-shortest-path.ts#L27
Accept<T>
distance src/find-shortest-path.ts#L20 Scaled<Distance<T>>
heuristic src/find-shortest-path.ts#L21 Scaled<Heuristic<T>>
maxIterations src/find-shortest-path.ts#L22 number
negativeHeap src/find-shortest-path.ts#L23 boolean
Heuristics = ... src/heuristics.ts#L3 # Euclidean = ... # Manhattan = ... } # findShortestPath(FindShortestPathOptions<T>) src/find-shortest-path.ts#L131 # findShortestPathBi(FindShortestPathOptions<T>) src/find-shortest-path.ts#L179
## Contributing
[Fork](https://github.com/stagas/find-shortest-path/fork) or [edit](https://github.dev/stagas/find-shortest-path) and submit a PR.
All contributions are welcome!
## License
MIT © 2022 [stagas](https://github.com/stagas)