Air-Quality-Web/client_src/js/Overlay/VoronoiOverlay.mjs
2019-06-11 00:32:01 +01:00

128 lines
3 KiB
JavaScript

"use strict";
import L from 'leaflet';
import { Delaunay } from 'd3-delaunay';
import Vector2 from '../Helpers/Vector2.mjs';
import Rectangle from '../Helpers/Rectangle.mjs';
import SvgWriter from '../Helpers/SvgWriter.mjs';
/**
* Generates and manages a single voronoi SVGOverlay layer.
*/
class VoronoiOverlay {
constructor() {
this.border = new Vector2(0.1, 0.1); // lat / long
this.cells = [];
}
/**
* Adds a cell to the voronoi overlay.
* @param {VoronoiCell} cells The cell to add. May be specified as many times as requires to add cells in bulk.
*/
addCells(...cells) {
this.cells.push(...cells);
}
/**
* Computes the bounding box of all the currently registered points.
* Includes a border, which is defined by this.border.
* @return {Rectangle} The bounding box of the currently registered points.
*/
computeBoundingBox() {
let result = {
x_min: Infinity,
x_max: -Infinity,
y_min: Infinity,
y_max: -Infinity
}
for(let cell of this.cells) {
// TODO: Remove this restriction
if(cell.point.y < 40) continue; // Exclude the freetown one for testing 'cause it's miles away
if(cell.point.x < result.x_min) result.x_min = cell.point.x;
if(cell.point.x > result.x_max) result.x_max = cell.point.x;
if(cell.point.y < result.y_min) result.y_min = cell.point.y;
if(cell.point.y > result.y_max) result.y_max = cell.point.y;
}
result.x_min -= this.border.x;
result.y_min -= this.border.y;
result.x_max += this.border.x;
result.y_max += this.border.y;
return new Rectangle(
result.x_min,
result.y_min,
result.x_max - result.x_min,
result.y_max - result.y_min
);
}
render() {
let bounding_box = this.computeBoundingBox();
let voronoi = Delaunay.from(this.cells.map(
(cell) => [cell.point.x, cell.point.y])
).voronoi([
bounding_box.x, bounding_box.y,
bounding_box.Right, bounding_box.Bottom
]);
console.log(voronoi);
// TODO: Map the generated polygons back onto this.cells
let i = 0;
for(let polygon of voronoi.cellPolygons()) {
let our_cell = this.cells[i];
our_cell.polygon = polygon.map((point) => new Vector2(...point));
i++;
}
console.log(this.cells);
let svg = new SvgWriter(
"100%", "100%",
bounding_box,
true
);
// TODO: Render the SVG here
for(let cell of this.cells) {
if(cell.polygon !== null) {
svg.addPolygon(
`hsla(${(Math.random()*360).toFixed(2)}, 50%, 50%, 0.6)`,
cell.polygon
);
}
svg.addCircle(cell.point, 0.005, "red");
}
svg.complete();
console.log(svg.toString());
return svg.toString();
}
add_to(map) {
let bounds = this.computeBoundingBox();
this.layer = L.svgOverlay(
SvgWriter.string2element(this.render()),
L.latLngBounds(
L.latLng(bounds.TopLeft.y, bounds.TopLeft.x),
L.latLng(bounds.BottomRight.y, bounds.BottomRight.x)
)
);
this.layer.addTo(map);
}
generate_overlay() {
// TODO: Generate the Leaflet SVGOverlay here
}
}
export default VoronoiOverlay;