Ticket #1200: 1200noscope.patch

source/simulation2/components/CCmpPathfinder_Vertex.cpp

@@ -556 +556 @@
     }
 };
 
+static const u8 LAZINESS = 2; // Maximum tradeoff: improvement to distance from goal <-> path length
+
 void CCmpPathfinder::ComputeShortPath(const IObstructionTestFilter& filter,
     entity_pos_t x0, entity_pos_t z0, entity_pos_t clearance,
     entity_pos_t range, const PathGoal& goal, pass_class_t passClass, WaypointPath& path)
@@ -791 +793 @@
     open.push(qiStart);
 
     u16 idBest = START_VERTEX_ID;
-    fixed hBest = start.h;
+    fixed hBest = start.h.Multiply(start.h);
 
     while (!open.empty())
     {
@@ -799 +801 @@
         VertexPriorityQueue::Item curr = open.pop();
         vertexes[curr.id].status = Vertex::CLOSED;
 
+
+        // The following trick selects the end point using a different criterion.
+        // This is mostly done because by the time the unit has traversed the path much could have changed,
+        // e.g. in case of lots of units swarming around a point.
+
+        if (vertexes[curr.id].h.Multiply(vertexes[curr.id].h)  + (vertexes[curr.id].g << LAZINESS) < hBest)
+        {
+            idBest = curr.id;
+            hBest = vertexes[curr.id].h.Multiply(vertexes[curr.id].h) + (vertexes[curr.id].g << LAZINESS);
+        }
+
         // If we've reached the destination, stop
         if (curr.id == GOAL_VERTEX_ID)
         {
@@ -910 +923 @@
 
                     VertexPriorityQueue::Item t = { (u16)n, g + vertexes[n].h, vertexes[n].h };
                     open.push(t);
-
-                    // Remember the heuristically best vertex we've seen so far, in case we never actually reach the target
-                    if (vertexes[n].h < hBest)
-                    {
-                        idBest = (u16)n;
-                        hBest = vertexes[n].h;
-                    }
                 }
                 else // must be OPEN
                 {