Ice Layer Data Model (#1262)

* prototype for ice seperation

* feat: migrate ice data to new data model and update version to 1.110.0

* refactor: update ice data handling and rendering for improved performance

* feat: integrate ice generation and recalculation in heightmap editing

* fix ice selection(hopefully)

* fix ice selection better(pls)

* refactor: remove redundant element selection in ice editing functions

* fix: clear ice data before generating glaciers and icebergs

* sparse array implementation with reduced updates

* fix logic chech in modules/dynamic/auto-update.js

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* fix: migrate ice data to new data model structure

* refactor: streamline ice generation process and clean up rendering functions

* refactor: simplify ice rendering logic by removing redundant clearing of old SVG

* fix: update editIce function to accept element parameter and improve logic for glacier handling

* ice drawing with only type on less occuring glaciers

* feat: add compactPackData function to filter out undefined glaciers and icebergs

* fix: clear existing ice elements before redrawing in editHeightmap function

* fix compact problems on autosave

* refactor: unify ice data structure and streamline ice element handling

* refactor: improve getNextId function to fill gaps in ice element IDs(optional commit)

* just to be sure

* bump version in html

* fix index.html script import

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

public/modules/ice.js

@@ -0,0 +1,170 @@
+"use strict";
+
+// Ice layer data model - separates ice data from SVG rendering
+window.Ice = (function () {
+
+  // Find next available id for new ice element idealy filling gaps
+  function getNextId() {
+    if (pack.ice.length === 0) return 0;
+    // find gaps in existing ids
+    const existingIds = pack.ice.map(e => e.i).sort((a, b) => a - b);
+    for (let id = 0; id < existingIds[existingIds.length - 1]; id++) {
+      if (!existingIds.includes(id)) return id;
+    }
+    return existingIds[existingIds.length - 1] + 1;
+  }
+
+  // Generate glaciers and icebergs based on temperature and height
+  function generate() {
+    clear();
+    const { cells, features } = grid;
+    const { temp, h } = cells;
+    Math.random = aleaPRNG(seed);
+
+    const ICEBERG_MAX_TEMP = 0;
+    const GLACIER_MAX_TEMP = -8;
+    const minMaxTemp = d3.min(temp);
+
+    // Generate glaciers on cold land
+    {
+      const type = "iceShield";
+      const getType = cellId =>
+        h[cellId] >= 20 && temp[cellId] <= GLACIER_MAX_TEMP ? type : null;
+      const isolines = getIsolines(grid, getType, { polygons: true });
+
+      if (isolines[type]?.polygons) {
+        isolines[type].polygons.forEach(points => {
+          const clipped = clipPoly(points);
+          pack.ice.push({
+            i: getNextId(),
+            points: clipped,
+            type: "glacier"
+          });
+        });
+      }
+    }
+
+    // Generate icebergs on cold water
+    for (const cellId of grid.cells.i) {
+      const t = temp[cellId];
+      if (h[cellId] >= 20) continue; // no icebergs on land
+      if (t > ICEBERG_MAX_TEMP) continue; // too warm: no icebergs
+      if (features[cells.f[cellId]].type === "lake") continue; // no icebergs on lakes
+      if (P(0.8)) continue; // skip most of eligible cells
+
+      const randomFactor = 0.8 + rand() * 0.4; // random size factor
+      let baseSize = (1 - normalize(t, minMaxTemp, 1)) * 0.8; // size: 0 = zero, 1 = full
+      if (cells.t[cellId] === -1) baseSize /= 1.3; // coastline: smaller icebergs
+      const size = minmax(rn(baseSize * randomFactor, 2), 0.1, 1);
+
+      const [cx, cy] = grid.points[cellId];
+      const points = getGridPolygon(cellId).map(([x, y]) => [
+        rn(lerp(cx, x, size), 2),
+        rn(lerp(cy, y, size), 2)
+      ]);
+
+      pack.ice.push({
+        i: getNextId(),
+        points,
+        type: "iceberg",
+        cellId,
+        size
+      });
+    }
+  }
+
+  function addIceberg(cellId, size) {
+    const [cx, cy] = grid.points[cellId];
+    const points = getGridPolygon(cellId).map(([x, y]) => [
+      rn(lerp(cx, x, size), 2),
+      rn(lerp(cy, y, size), 2)
+    ]);
+    const id = getNextId();
+    pack.ice.push({
+      i: id,
+      points,
+      type: "iceberg",
+      cellId,
+      size
+    });
+    redrawIceberg(id);
+  }
+
+  function removeIce(id) {
+    const index = pack.ice.findIndex(element => element.i === id);
+    if (index !== -1) {
+      const type = pack.ice.find(element => element.i === id).type;
+      pack.ice.splice(index, 1);
+      if (type === "glacier") {
+        redrawGlacier(id);
+      } else {
+        redrawIceberg(id);
+      }
+      
+    }
+  }
+
+  function updateIceberg(id, points, size) {
+    const iceberg = pack.ice.find(element => element.i === id);
+    if (iceberg) {
+      iceberg.points = points;
+      iceberg.size = size;
+    }
+  }
+
+  function randomizeIcebergShape(id) {
+    const iceberg = pack.ice.find(element => element.i === id);
+    if (!iceberg) return;
+
+    const cellId = iceberg.cellId;
+    const size = iceberg.size;
+    const [cx, cy] = grid.points[cellId];
+
+    // Get a different random cell for the polygon template
+    const i = ra(grid.cells.i);
+    const cn = grid.points[i];
+    const poly = getGridPolygon(i).map(p => [p[0] - cn[0], p[1] - cn[1]]);
+    const points = poly.map(p => [
+      rn(cx + p[0] * size, 2),
+      rn(cy + p[1] * size, 2)
+    ]);
+
+    iceberg.points = points;
+  }
+
+  function changeIcebergSize(id, newSize) {
+    const iceberg = pack.ice.find(element => element.i === id);
+    if (!iceberg) return;
+
+    const cellId = iceberg.cellId;
+    const [cx, cy] = grid.points[cellId];
+    const oldSize = iceberg.size;
+
+    const flat = iceberg.points.flat();
+    const pairs = [];
+    while (flat.length) pairs.push(flat.splice(0, 2));
+    const poly = pairs.map(p => [(p[0] - cx) / oldSize, (p[1] - cy) / oldSize]);
+    const points = poly.map(p => [
+      rn(cx + p[0] * newSize, 2),
+      rn(cy + p[1] * newSize, 2)
+    ]);
+
+    iceberg.points = points;
+    iceberg.size = newSize;
+  }
+
+  // Clear all ice
+  function clear() {
+    pack.ice = [];
+  }
+
+  return {
+    generate,
+    addIceberg,
+    removeIce,
+    updateIceberg,
+    randomizeIcebergShape,
+    changeIcebergSize,
+    clear
+  };
+})();