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- import intersectLine from './intersect-line'
- /*
- * Returns the point ({x, y}) at which the point argument intersects with the
- * node argument assuming that it has the shape specified by polygon.
- */
- function intersectPolygon (node, polyPoints, point) {
- const x1 = node.x
- const y1 = node.y
- const intersections = []
- let minX = Number.POSITIVE_INFINITY
- let minY = Number.POSITIVE_INFINITY
- polyPoints.forEach(function (entry) {
- minX = Math.min(minX, entry.x)
- minY = Math.min(minY, entry.y)
- })
- const left = x1 - node.width / 2 - minX
- const top = y1 - node.height / 2 - minY
- for (let i = 0; i < polyPoints.length; i += 1) {
- const p1 = polyPoints[i]
- const p2 = polyPoints[i < polyPoints.length - 1 ? i + 1 : 0]
- const intersect = intersectLine(node, point,
- {x: left + p1.x, y: top + p1.y}, {x: left + p2.x, y: top + p2.y})
- if (intersect) {
- intersections.push(intersect)
- }
- }
- if (!intersections.length) {
- console.log('NO INTERSECTION FOUND, RETURN NODE CENTER', node)
- return node
- }
- if (intersections.length > 1) {
- // More intersections, find the one nearest to edge end point
- intersections.sort(function (p, q) {
- const pdx = p.x - point.x
- const pdy = p.y - point.y
- const distp = Math.sqrt(pdx * pdx + pdy * pdy)
- const qdx = q.x - point.x
- const qdy = q.y - point.y
- const distq = Math.sqrt(qdx * qdx + qdy * qdy)
- return (distp < distq) ? -1 : (distp === distq ? 0 : 1)
- })
- }
- return intersections[0]
- }
- export default intersectPolygon
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