chore: split public and src

public/modules/lakes.js

@@ -0,0 +1,123 @@
+"use strict";
+
+window.Lakes = (function () {
+  const LAKE_ELEVATION_DELTA = 0.1;
+
+  // check if lake can be potentially open (not in deep depression)
+  const detectCloseLakes = h => {
+    const {cells} = pack;
+    const ELEVATION_LIMIT = +byId("lakeElevationLimitOutput").value;
+
+    pack.features.forEach(feature => {
+      if (feature.type !== "lake") return;
+      delete feature.closed;
+
+      const MAX_ELEVATION = feature.height + ELEVATION_LIMIT;
+      if (MAX_ELEVATION > 99) {
+        feature.closed = false;
+        return;
+      }
+
+      let isDeep = true;
+      const lowestShorelineCell = feature.shoreline.sort((a, b) => h[a] - h[b])[0];
+      const queue = [lowestShorelineCell];
+      const checked = [];
+      checked[lowestShorelineCell] = true;
+
+      while (queue.length && isDeep) {
+        const cellId = queue.pop();
+
+        for (const neibCellId of cells.c[cellId]) {
+          if (checked[neibCellId]) continue;
+          if (h[neibCellId] >= MAX_ELEVATION) continue;
+
+          if (h[neibCellId] < 20) {
+            const nFeature = pack.features[cells.f[neibCellId]];
+            if (nFeature.type === "ocean" || feature.height > nFeature.height) isDeep = false;
+          }
+
+          checked[neibCellId] = true;
+          queue.push(neibCellId);
+        }
+      }
+
+      feature.closed = isDeep;
+    });
+  };
+
+  const defineClimateData = function (heights) {
+    const {cells, features} = pack;
+    const lakeOutCells = new Uint16Array(cells.i.length);
+
+    features.forEach(feature => {
+      if (feature.type !== "lake") return;
+      feature.flux = getFlux(feature);
+      feature.temp = getLakeTemp(feature);
+      feature.evaporation = getLakeEvaporation(feature);
+      if (feature.closed) return; // no outlet for lakes in depressed areas
+
+      feature.outCell = getLowestShoreCell(feature);
+      lakeOutCells[feature.outCell] = feature.i;
+    });
+
+    return lakeOutCells;
+
+    function getFlux(lake) {
+      return lake.shoreline.reduce((acc, c) => acc + grid.cells.prec[cells.g[c]], 0);
+    }
+
+    function getLakeTemp(lake) {
+      if (lake.cells < 6) return grid.cells.temp[cells.g[lake.firstCell]];
+      return rn(d3.mean(lake.shoreline.map(c => grid.cells.temp[cells.g[c]])), 1);
+    }
+
+    function getLakeEvaporation(lake) {
+      const height = (lake.height - 18) ** heightExponentInput.value; // height in meters
+      const evaporation = ((700 * (lake.temp + 0.006 * height)) / 50 + 75) / (80 - lake.temp); // based on Penman formula, [1-11]
+      return rn(evaporation * lake.cells);
+    }
+
+    function getLowestShoreCell(lake) {
+      return lake.shoreline.sort((a, b) => heights[a] - heights[b])[0];
+    }
+  };
+
+  const cleanupLakeData = function () {
+    for (const feature of pack.features) {
+      if (feature.type !== "lake") continue;
+      delete feature.river;
+      delete feature.enteringFlux;
+      delete feature.outCell;
+      delete feature.closed;
+      feature.height = rn(feature.height, 3);
+
+      const inlets = feature.inlets?.filter(r => pack.rivers.find(river => river.i === r));
+      if (!inlets || !inlets.length) delete feature.inlets;
+      else feature.inlets = inlets;
+
+      const outlet = feature.outlet && pack.rivers.find(river => river.i === feature.outlet);
+      if (!outlet) delete feature.outlet;
+    }
+  };
+
+  const getHeight = function (feature) {
+    const heights = pack.cells.h;
+    const minShoreHeight = d3.min(feature.shoreline.map(cellId => heights[cellId])) || 20;
+    return rn(minShoreHeight - LAKE_ELEVATION_DELTA, 2);
+  };
+
+  const defineNames = function () {
+    pack.features.forEach(feature => {
+      if (feature.type !== "lake") return;
+      feature.name = getName(feature);
+    });
+  };
+
+  const getName = function (feature) {
+    const landCell = feature.shoreline[0];
+    const culture = pack.cells.culture[landCell];
+    return Names.getCulture(culture);
+  };
+
+  return {defineClimateData, cleanupLakeData, detectCloseLakes, getHeight, defineNames, getName};
+})();