refactor: submap - add middle points

modules/resample.js

@@ -109,17 +109,23 @@ window.Resample = (function () {
     pack.cells.conf = new Uint8Array(pack.cells.i.length);
     const offset = grid.spacing * 2;
 
+    const getCellCost = cellId => {
+      if (pack.cells.h[cellId] < 20) return Infinity;
+      return pack.cells.h[cellId];
+    };
+
     pack.rivers = parentMap.pack.rivers
       .map(river => {
         const parentPoints = river.points || river.cells.map(cellId => parentMap.pack.cells.p[cellId]);
-        const points = parentPoints
+        const newPoints = parentPoints
           .map(([parentX, parentY]) => {
             const [x, y] = projection(parentX, parentY);
             return isInMap(x, y, offset) ? [rn(x, 2), rn(y, 2)] : null;
           })
           .filter(Boolean);
-        if (points.length < 2) return null;
+        if (newPoints.length < 2) return null;
 
+        const points = addIntermidiatePoints(newPoints, getCellCost);
         const cells = points.map(point => findCell(...point));
         cells.forEach(cellId => {
           if (pack.cells.r[cellId]) pack.cells.conf[cellId] = 1;
@@ -327,6 +333,23 @@ window.Resample = (function () {
     );
   }
 
+  // fill gaps in points array with intermidiate points
+  function addIntermidiatePoints(points, getCellCost) {
+    const newPoints = [];
+
+    for (let i = 0; i < points.length; i++) {
+      newPoints.push(points[i]);
+      if (points[i + 1]) {
+        const start = findCell(...points[i]);
+        const exit = findCell(...points[i + 1]);
+        const pathCells = findPath(start, exit, getCellCost);
+        if (pathCells) newPoints.push(...pathCells.map(cellId => pack.cells.p[cellId]));
+      }
+    }
+
+    return newPoints;
+  }
+
   function isWater(graph, cellId) {
     return graph.cells.h[cellId] < 20;
   }

modules/routes-generator.js

@@ -290,8 +290,8 @@ window.Routes = (function () {
           const connectionModifier = connections.has(`${next}-${neibCellId}`) ? 1 : 2;
           const burgModifier = cells.burg[neibCellId] ? 1 : 3;
 
-          const cellsCost = distanceCost * habitabilityModifier * heightModifier * connectionModifier * burgModifier;
-          const totalCost = priority + cellsCost;
+          const cellCost = distanceCost * habitabilityModifier * heightModifier * connectionModifier * burgModifier;
+          const totalCost = priority + cellCost;
 
           if (totalCost >= cost[neibCellId]) continue;
           from[neibCellId] = next;

utils/pathUtils.js

@@ -176,3 +176,66 @@ function connectVertices({vertices, startingVertex, ofSameType, addToChecked, cl
   if (closeRing) chain.push(startingVertex);
   return chain;
 }
+
+/**
+ * Finds the shortest path between two cells using a cost-based pathfinding algorithm.
+ * @param {number} start - The ID of the starting cell.
+ * @param {number} exit - The ID of the destination cell.
+ * @param {function} getCellCost - A function that returns the cost of a cell. Should return Infinity for impassable cells.
+ * @returns {number[]|null} An array of cell IDs of the path from start to exit, or null if no path is found or start and exit are the same.
+ */
+function findPath(start, exit, getCellCost) {
+  if (start === exit) return null;
+
+  const from = [];
+  const cost = [];
+  const queue = new FlatQueue();
+  queue.push(start, 0);
+
+  let iteration = 0;
+
+  while (queue.length) {
+    const priority = queue.peekValue();
+    const next = queue.pop();
+    iteration++;
+    console.log(iteration, next);
+
+    for (const neibCellId of pack.cells.c[next]) {
+      if (neibCellId === exit) {
+        from[neibCellId] = next;
+        return restorePath(start, exit, from);
+      }
+
+      const cellCost = getCellCost(neibCellId);
+      if (cellCost === Infinity) continue; // impassable cell
+
+      const distanceCost = dist2(pack.cells.p[next], pack.cells.p[neibCellId]);
+      const totalCost = priority + distanceCost + getCellCost(neibCellId);
+
+      if (totalCost >= cost[neibCellId]) continue;
+      from[neibCellId] = next;
+      cost[neibCellId] = totalCost;
+      queue.push(neibCellId, totalCost);
+    }
+  }
+
+  return null;
+}
+
+// supplementary function for findPath
+function restorePath(start, exit, from) {
+  const pathCells = [];
+
+  let current = exit;
+  let prev = exit;
+
+  while (current !== start) {
+    pathCells.push(current);
+    prev = from[current];
+    current = prev;
+  }
+
+  pathCells.push(current);
+
+  return pathCells;
+}