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import {isCounterClockwise} from './util';
import Point from '@mapbox/point-geometry';
export {polygonIntersectsBufferedPoint, polygonIntersectsMultiPolygon, polygonIntersectsBufferedMultiLine, polygonIntersectsPolygon, distToSegmentSquared, polygonIntersectsBox};
type Line = Array<Point>;
type MultiLine = Array<Line>;
type Ring = Array<Point>;
type Polygon = Array<Point>;
type MultiPolygon = Array<Polygon>;
function polygonIntersectsPolygon(polygonA: Polygon, polygonB: Polygon) {
for (let i = 0; i < polygonA.length; i++) {
if (polygonContainsPoint(polygonB, polygonA[i])) return true;
}
for (let i = 0; i < polygonB.length; i++) {
if (polygonContainsPoint(polygonA, polygonB[i])) return true;
}
if (lineIntersectsLine(polygonA, polygonB)) return true;
return false;
}
function polygonIntersectsBufferedPoint(polygon: Polygon, point: Point, radius: number) {
if (polygonContainsPoint(polygon, point)) return true;
if (pointIntersectsBufferedLine(point, polygon, radius)) return true;
return false;
}
function polygonIntersectsMultiPolygon(polygon: Polygon, multiPolygon: MultiPolygon) {
if (polygon.length === 1) {
return multiPolygonContainsPoint(multiPolygon, polygon[0]);
}
for (let m = 0; m < multiPolygon.length; m++) {
const ring = multiPolygon[m];
for (let n = 0; n < ring.length; n++) {
if (polygonContainsPoint(polygon, ring[n])) return true;
}
}
for (let i = 0; i < polygon.length; i++) {
if (multiPolygonContainsPoint(multiPolygon, polygon[i])) return true;
}
for (let k = 0; k < multiPolygon.length; k++) {
if (lineIntersectsLine(polygon, multiPolygon[k])) return true;
}
return false;
}
function polygonIntersectsBufferedMultiLine(polygon: Polygon, multiLine: MultiLine, radius: number) {
for (let i = 0; i < multiLine.length; i++) {
const line = multiLine[i];
if (polygon.length >= 3) {
for (let k = 0; k < line.length; k++) {
if (polygonContainsPoint(polygon, line[k])) return true;
}
}
if (lineIntersectsBufferedLine(polygon, line, radius)) return true;
}
return false;
}
function lineIntersectsBufferedLine(lineA: Line, lineB: Line, radius: number) {
if (lineA.length > 1) {
if (lineIntersectsLine(lineA, lineB)) return true;
// Check whether any point in either line is within radius of the other line
for (let j = 0; j < lineB.length; j++) {
if (pointIntersectsBufferedLine(lineB[j], lineA, radius)) return true;
}
}
for (let k = 0; k < lineA.length; k++) {
if (pointIntersectsBufferedLine(lineA[k], lineB, radius)) return true;
}
return false;
}
function lineIntersectsLine(lineA: Line, lineB: Line) {
if (lineA.length === 0 || lineB.length === 0) return false;
for (let i = 0; i < lineA.length - 1; i++) {
const a0 = lineA[i];
const a1 = lineA[i + 1];
for (let j = 0; j < lineB.length - 1; j++) {
const b0 = lineB[j];
const b1 = lineB[j + 1];
if (lineSegmentIntersectsLineSegment(a0, a1, b0, b1)) return true;
}
}
return false;
}
function lineSegmentIntersectsLineSegment(a0: Point, a1: Point, b0: Point, b1: Point) {
return isCounterClockwise(a0, b0, b1) !== isCounterClockwise(a1, b0, b1) &&
isCounterClockwise(a0, a1, b0) !== isCounterClockwise(a0, a1, b1);
}
function pointIntersectsBufferedLine(p: Point, line: Line, radius: number) {
const radiusSquared = radius * radius;
if (line.length === 1) return p.distSqr(line[0]) < radiusSquared;
for (let i = 1; i < line.length; i++) {
// Find line segments that have a distance <= radius^2 to p
// In that case, we treat the line as "containing point p".
const v = line[i - 1], w = line[i];
if (distToSegmentSquared(p, v, w) < radiusSquared) return true;
}
return false;
}
// Code from http://stackoverflow.com/a/1501725/331379.
function distToSegmentSquared(p: Point, v: Point, w: Point) {
const l2 = v.distSqr(w);
if (l2 === 0) return p.distSqr(v);
const t = ((p.x - v.x) * (w.x - v.x) + (p.y - v.y) * (w.y - v.y)) / l2;
if (t < 0) return p.distSqr(v);
if (t > 1) return p.distSqr(w);
return p.distSqr(w.sub(v)._mult(t)._add(v));
}
// point in polygon ray casting algorithm
function multiPolygonContainsPoint(rings: Array<Ring>, p: Point) {
let c = false,
ring, p1, p2;
for (let k = 0; k < rings.length; k++) {
ring = rings[k];
for (let i = 0, j = ring.length - 1; i < ring.length; j = i++) {
p1 = ring[i];
p2 = ring[j];
if (((p1.y > p.y) !== (p2.y > p.y)) && (p.x < (p2.x - p1.x) * (p.y - p1.y) / (p2.y - p1.y) + p1.x)) {
c = !c;
}
}
}
return c;
}
function polygonContainsPoint(ring: Ring, p: Point) {
let c = false;
for (let i = 0, j = ring.length - 1; i < ring.length; j = i++) {
const p1 = ring[i];
const p2 = ring[j];
if (((p1.y > p.y) !== (p2.y > p.y)) && (p.x < (p2.x - p1.x) * (p.y - p1.y) / (p2.y - p1.y) + p1.x)) {
c = !c;
}
}
return c;
}
function polygonIntersectsBox(ring: Ring, boxX1: number, boxY1: number, boxX2: number, boxY2: number) {
for (const p of ring) {
if (boxX1 <= p.x &&
boxY1 <= p.y &&
boxX2 >= p.x &&
boxY2 >= p.y) return true;
}
const corners = [
new Point(boxX1, boxY1),
new Point(boxX1, boxY2),
new Point(boxX2, boxY2),
new Point(boxX2, boxY1)];
if (ring.length > 2) {
for (const corner of corners) {
if (polygonContainsPoint(ring, corner)) return true;
}
}
for (let i = 0; i < ring.length - 1; i++) {
const p1 = ring[i];
const p2 = ring[i + 1];
if (edgeIntersectsBox(p1, p2, corners)) return true;
}
return false;
}
function edgeIntersectsBox(e1: Point, e2: Point, corners: Array<Point>) {
const tl = corners[0];
const br = corners[2];
// the edge and box do not intersect in either the x or y dimensions
if (((e1.x < tl.x) && (e2.x < tl.x)) ||
((e1.x > br.x) && (e2.x > br.x)) ||
((e1.y < tl.y) && (e2.y < tl.y)) ||
((e1.y > br.y) && (e2.y > br.y))) return false;
// check if all corners of the box are on the same side of the edge
const dir = isCounterClockwise(e1, e2, corners[0]);
return dir !== isCounterClockwise(e1, e2, corners[1]) ||
dir !== isCounterClockwise(e1, e2, corners[2]) ||
dir !== isCounterClockwise(e1, e2, corners[3]);
}
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