From 2c953496f7750c1953fe6934c6cb548bb93cff44 Mon Sep 17 00:00:00 2001 From: Casper Lamboo Date: Wed, 2 May 2018 17:42:31 +0200 Subject: [PATCH] share functions in comb.js --- comb.js | 214 +------------------------------ src/sliceActions/helpers/comb.js | 12 +- 2 files changed, 10 insertions(+), 216 deletions(-) diff --git a/comb.js b/comb.js index 27ec53a..f481e37 100644 --- a/comb.js +++ b/comb.js @@ -1,211 +1,5 @@ -import earcut from 'earcut'; import { add, divide, distanceTo, normalize, subtract, normal, dot } from './src/sliceActions/helpers/vector2.js'; - -function lineIntersection(a1, a2, b1, b2) { - // source: http://mathworld.wolfram.com/Line-LineIntersection.html - const intersection = { - x: ((a1.x * a2.y - a1.y * a2.x) * (b1.x - b2.x) - (a1.x - a2.x) * (b1.x * b2.y - b1.y * b2.x)) / ((a1.x - a2.x) * (b1.y - b2.y) - (a1.y - a2.y) * (b1.x - b2.x)), - y: ((a1.x * a2.y - a1.y * a2.x) * (b1.y - b2.y) - (a1.y - a2.y) * (b1.x * b2.y - b1.y * b2.x)) / ((a1.x - a2.x) * (b1.y - b2.y) - (a1.y - a2.y) * (b1.x - b2.x)) - }; - - const intersectionA = subtract(intersection, a1); - const directionA = subtract(a2, a1); - const normalA = normalize(directionA); - const distanceA = dot(normalA, intersectionA); - if (distanceA < 0 || distanceA > dot(normalA, directionA)) return false; - - const intersectionB = subtract(intersection, b1); - const directionB = subtract(b2, b1); - const normalB = normalize(directionB); - const distanceB = dot(normalB, intersectionB); - if (distanceB < 0 || distanceB > dot(normalB, directionB)) return false; - - return intersection; -} - -function pointIsInsideConvex(point, convex, vertices) { - for (let i = 0; i < convex.length; i ++) { - const vertexA = vertices[convex[i]]; - const vertexB = vertices[convex[(i + 1) % convex.length]]; - - const n = normalize(normal(subtract(vertexB, vertexA))); - const p = subtract(point, vertexA); - - if (dot(p, n) < 0) return false; - } - return true; -} - -function decompose(polygon) { - const vertices = polygon.reduce((points, path) => { - points.push(...path); - return points; - }, []); - const flatVertices = vertices.reduce((points, { x, y }) => { - points.push(x, y); - return points; - }, []); - let offset = 0; - const holes = polygon - .map(path => offset += path.length) - .slice(0, -1); - - const flatTrainglesIndexed = earcut(flatVertices, holes); - const convexPolygons = []; - for (let i = 0; i < flatTrainglesIndexed.length; i += 3) { - const face = [ - flatTrainglesIndexed[i], - flatTrainglesIndexed[i + 1], - flatTrainglesIndexed[i + 2] - ]; - const center = divide(face.reduce((total, point) => { - if (!total) { - return vertices[point]; - } else { - return add(total, vertices[point]); - } - }, null), face.length); - convexPolygons.push({ - center, - face, - connects: [] - }); - } - - for (let i = 0; i < convexPolygons.length; i ++) { - for (let j = i + 1; j < convexPolygons.length; j ++) { - const triangleIndexedA = convexPolygons[i]; - const triangleIndexedB = convexPolygons[j]; - - const overlap = []; - triangleIndexedA.face.map(index => { - if (triangleIndexedB.face.includes(index)) overlap.push(index); - }); - - if (overlap.length === 2) { - const distance = distanceTo(convexPolygons[i].center, convexPolygons[j].center); - triangleIndexedA.connects.push({ to: j, edge: overlap, distance }); - triangleIndexedB.connects.push({ to: i, edge: overlap, distance }); - } - } - } - - return { vertices, convexPolygons }; -} - -// const distanceMap = new WeakMap(); -// function findClosestPath(convexPolygons, start, end, visited = [], path = [], distance = 0) { -// if (start === end) return []; -// -// visited = [...visited, start]; -// -// const { connects } = convexPolygons[start]; -// -// const finish = connects.find(({ to }) => to === end); -// if (finish) return [...path, finish]; -// -// const posibilities = []; -// for (let i = 0; i < connects.length; i ++) { -// const connect = connects[i]; -// if (visited.includes(connect.to)) continue; -// -// const positibiltyDistance = distance + connect.distance; -// const posibility = findClosestPath(convexPolygons, connect.to, end, visited, [...path, connect], positibiltyDistance); -// if (posibility) { -// posibilities.push(posibility); -// distanceMap.set(posibility, positibiltyDistance); -// } -// } -// -// if (posibilities.length === 0) { -// return null; -// } else if (posibilities.length === 1) { -// return posibilities[0]; -// } else if (posibilities.length > 1) { -// return posibilities.sort((a, b) => distanceMap.get(a) - distanceMap.get(b))[0]; -// } -// } - -const findKey = _key => ({ key }) => _key === key; -function findClosestPath(map, start, end) { - // dijkstra's algorithm - const distances = { [start]: 0 }; - const open = [{ key: 0, nodes: [start] }]; - const predecessors = {}; - - while (open.length !== 0) { - const key = Math.min(...open.map(n => n.key).sort()); - const bucket = open.find(findKey(key)); - const node = bucket.nodes.shift(); - const currentDistance = key; - const { connects } = map[node]; - - if (bucket.nodes.length === 0) open.splice(open.indexOf(bucket), 1); - - for (let i = 0; i < connects.length; i ++) { - const { distance, to } = connects[i]; - const totalDistance = distance + currentDistance; - const vertexDistance = distances[to]; - - if ((typeof vertexDistance === 'undefined') || (vertexDistance > totalDistance)) { - distances[to] = totalDistance; - - let openNode = open.find(findKey(totalDistance)); - if (!openNode) { - openNode = { key: totalDistance, nodes: [] }; - open.push(openNode); - } - openNode.nodes.push(to); - - predecessors[to] = node; - } - } - } - - if (typeof distances[end] === 'undefined') return null; - - const nodes = []; - let node = end; - while (typeof node !== 'undefined') { - nodes.push(node); - node = predecessors[node]; - } - nodes.reverse(); - - const path = []; - for (let i = 1; i < nodes.length; i ++) { - const from = nodes[i - 1]; - const to = nodes[i]; - - const connection = map[from].connects.find(connect => connect.to === to); - path.push(connection); - } - - return path; -} - -function containLineInPath(path, start, end, vertices) { - const line = [start]; - - for (let i = 0; i < path.length; i ++) { - const { edge: [indexA, indexB] } = path[i]; - const vertexA = vertices[indexA]; - const vertexB = vertices[indexB]; - - const intersection = lineIntersection(start, end, vertexA, vertexB); - if (!intersection) { - const lastPoint = line[line.length - 1]; - const distanceA = distanceTo(lastPoint, vertexA) + distanceTo(vertexA, end); - const distanceB = distanceTo(lastPoint, vertexB) + distanceTo(vertexB, end); - - line.push(distanceA < distanceB ? vertexA : vertexB); - } - } - - line.push(end); - return line; -} - +import { pointIsInsideConvex, decompose, findClosestPath, containLineInPath } from './src/sliceActions/helpers/comb.js'; const canvas = document.createElement('canvas'); document.body.appendChild(canvas); @@ -228,8 +22,8 @@ function circle(radius = 10, x = 0, y = 0, clockWise = true, segments = 40) { return shape; } -const START = { x: 300, y: 40 }; -const END = { x: 300, y: 20 }; +const START = { x: 30, y: 550 }; +const END = { x: 400, y: 300 }; // const CONCAVE_POLYGON = [[ // { x: 10, y: 10 }, // { x: 600, y: 10 }, @@ -240,7 +34,7 @@ const END = { x: 300, y: 20 }; // { x: 160, y: 120 }, // { x: 120, y: 400 }, // { x: 400, y: 400 } -// ], circle(50, 300, 100, false)]; +// ]]; const CONCAVE_POLYGON = [ circle(300, 305, 305, true), circle(40, 305, 105, false), diff --git a/src/sliceActions/helpers/comb.js b/src/sliceActions/helpers/comb.js index cabe83a..e932808 100644 --- a/src/sliceActions/helpers/comb.js +++ b/src/sliceActions/helpers/comb.js @@ -43,7 +43,7 @@ function lineIntersection(a1, a2, b1, b2) { return intersection; } -function pointIsInsideConvex(point, convex, vertices) { +export function pointIsInsideConvex(point, convex, vertices) { for (let i = 0; i < convex.length; i ++) { const vertexA = vertices[convex[i]]; const vertexB = vertices[convex[(i + 1) % convex.length]]; @@ -56,7 +56,7 @@ function pointIsInsideConvex(point, convex, vertices) { return true; } -function decompose(polygon) { +export function decompose(polygon) { const vertices = polygon.reduce((points, path) => { points.push(...path); return points; @@ -114,7 +114,7 @@ function decompose(polygon) { } // const distanceMap = new WeakMap(); -// function findClosestPath(convexPolygons, start, end, visited = [], path = [], distance = 0) { +// export function findClosestPath(convexPolygons, start, end, visited = [], path = [], distance = 0) { // if (start === end) return []; // // visited = [...visited, start]; @@ -147,7 +147,7 @@ function decompose(polygon) { // } const findKey = _key => ({ key }) => _key === key; -function findClosestPath(map, start, end) { +export function findClosestPath(map, start, end) { // dijkstra's algorithm const distances = { [start]: 0 }; const open = [{ key: 0, nodes: [start] }]; @@ -204,7 +204,7 @@ function findClosestPath(map, start, end) { return path; } -function containLineInPath(path, start, end, vertices) { +export function containLineInPath(path, start, end, vertices) { let line = [start]; for (let i = 0; i < path.length; i ++) { @@ -215,7 +215,7 @@ function containLineInPath(path, start, end, vertices) { const intersection = lineIntersection(lastPoint, end, vertexA, vertexB); if (!intersection) { - line = containLineInPath(path.slice(0, i), start, lastPoint, vertices); + // line = containLineInPath(path.slice(0, i), start, lastPoint, vertices); const distanceA = distanceTo(lastPoint, vertexA) + distanceTo(vertexA, end); const distanceB = distanceTo(lastPoint, vertexB) + distanceTo(vertexB, end);