chore: modularize main.js

src/scripts/reGraph.js

@@ -0,0 +1,60 @@
+import {TIME} from "config/logging";
+import {UINT16_MAX} from "constants";
+import {createTypedArray} from "utils/arrayUtils";
+import {calculateVoronoi, getPackPolygon} from "utils/graphUtils";
+import {rn} from "utils/numberUtils";
+
+// recalculate Voronoi Graph to pack cells
+export function reGraph() {
+  TIME && console.time("reGraph");
+  const {cells: gridCells, points, features} = grid;
+  const newCells = {p: [], g: [], h: []}; // store new data
+  const spacing2 = grid.spacing ** 2;
+
+  for (const i of gridCells.i) {
+    const height = gridCells.h[i];
+    const type = gridCells.t[i];
+    if (height < 20 && type !== -1 && type !== -2) continue; // exclude all deep ocean points
+    if (type === -2 && (i % 4 === 0 || features[gridCells.f[i]].type === "lake")) continue; // exclude non-coastal lake points
+    const [x, y] = points[i];
+
+    addNewPoint(i, x, y, height);
+
+    // add additional points for cells along coast
+    if (type === 1 || type === -1) {
+      if (gridCells.b[i]) continue; // not for near-border cells
+      gridCells.c[i].forEach(e => {
+        if (i > e) return;
+        if (gridCells.t[e] === type) {
+          const dist2 = (y - points[e][1]) ** 2 + (x - points[e][0]) ** 2;
+          if (dist2 < spacing2) return; // too close to each other
+          const x1 = rn((x + points[e][0]) / 2, 1);
+          const y1 = rn((y + points[e][1]) / 2, 1);
+          addNewPoint(i, x1, y1, height);
+        }
+      });
+    }
+  }
+
+  function addNewPoint(i, x, y, height) {
+    newCells.p.push([x, y]);
+    newCells.g.push(i);
+    newCells.h.push(height);
+  }
+
+  function getCellArea(i) {
+    const area = Math.abs(d3.polygonArea(getPackPolygon(i)));
+    return Math.min(area, UINT16_MAX);
+  }
+
+  const {cells: packCells, vertices} = calculateVoronoi(newCells.p, grid.boundary);
+  pack.vertices = vertices;
+  pack.cells = packCells;
+  pack.cells.p = newCells.p;
+  pack.cells.g = createTypedArray({maxValue: grid.points.length, from: newCells.g});
+  pack.cells.q = d3.quadtree(newCells.p.map(([x, y], i) => [x, y, i]));
+  pack.cells.h = createTypedArray({maxValue: 100, from: newCells.h});
+  pack.cells.area = createTypedArray({maxValue: UINT16_MAX, from: pack.cells.i}).map(getCellArea);
+
+  TIME && console.timeEnd("reGraph");
+}