Initial commit

Worker/Player.js

@@ -0,0 +1,77 @@
+const { parentPort }        = require("worker_threads");
+
+const PriorityQueue         = require("../Utility/PriorityQueue");
+
+const grids                 = require("../Game/Grids");
+
+const COUNT_NEIGHBOURS      = 4;
+
+parentPort.on("message", d => {
+    const { destination, position, id, mapId, wasMoving, movementRequestTracker } = d;
+    const grid = grids[mapId - 1];
+
+    const start = grid.getCell(position.x, position.y);
+    const open = new PriorityQueue();
+    const openRead = {};
+    const close = {};
+
+    open.enqueue({ 
+        xw: start.xw, 
+        xh: start.xh, 
+        gCost: 0, 
+        hCost: 0,
+        fCost: 0 
+    }, 0);
+    
+    while (open.items.length > 0) {
+        const current = open.dequeue();
+        if (current.xw === destination.xw && current.xh === destination.xh) {
+            const path = backtrace(current, grid);
+            const startingPosition = path.shift();
+
+            return parentPort.postMessage({ 
+                startingPosition, 
+                path, 
+                id, 
+                mapId, 
+                wasMoving, 
+                movementRequestTracker
+            });
+        };
+      
+        close[`${current.xw}-${current.xh}`] = current;
+
+        const neighbours = grid.getNodeNeighbours(current);
+        for (let i = 0; i < COUNT_NEIGHBOURS; i++) {
+            const n = neighbours[i];
+            if (!grid.isValidNode(n)) continue;
+            
+            let closed = close[`${n.xw}-${n.xh}`]; 
+            if (closed) continue;
+            
+            let alreadyIn = openRead[`${n.xw}-${n.xh}`];
+            if (alreadyIn) continue;            
+
+            n.hCost = Math.abs(n.xw - destination.xw) + Math.abs(n.xh - destination.xh);
+            n.gCost = current.gCost + 1;
+            n.fCost = n.gCost + n.hCost;
+            n.parent = current;
+
+            open.enqueue(n, n.hCost);
+            openRead[`${n.xw}-${n.xh}`] = n;
+        };
+    };
+});
+
+function backtrace(node, map) {
+	let coords = map.getCoords(node.xw, node.xh);
+	let path = [[coords.x, coords.y]];
+
+	while (node.parent) {
+		node = node.parent;
+		coords = map.getCoords(node.xw, node.xh);
+		path.push([coords.x, coords.y]);
+	};
+
+	return path.reverse();
+};