Added BFS

src/main/kotlin/BFSPathFinder.kt

@@ -1,10 +1,13 @@
 package technology.zim
 
+import technology.zim.data.Directions
 import technology.zim.data.Tile
+import technology.zim.data.TileNavigatedArray
 
 object BFSPathFinder {
     //In this particular situation, only a single outcome is likely. Thus, BFS always finds the perfect (and only) path
     //Skipping the Heap data structure allows better utilization of on-die cache
+    var gVals:TileNavigatedArray<Int> = TileNavigatedArray<Int>()
 
     fun generatePath(start: Tile, end: Tile) {
         if (!start.isInBounds() || !end.isInBounds()) {
@@ -15,21 +18,48 @@ object BFSPathFinder {
             println("Ouroboros detected")
             return
         }
+        gVals = TileNavigatedArray<Int>(World.sizeX, World.sizeY, false)
 
         //Queue for tiles to be checked
         val frontier = ArrayDeque<Tile>()
         frontier.addLast(start)
+        gVals.set(start, 0)
+        World.update(start, Directions.BFSFRONTIER)
 
+        var current:Tile
         while (frontier.isNotEmpty()) {
-            //Grab the next tile
-            
-            // Mark it explored
+            //Grab the next tile and its gValue
+            current = frontier.removeFirst()
+            val currentG = gVals.get(current)?:Int.MAX_VALUE-1.also{throw IndexOutOfBoundsException("Couldn't get gValue in BFS")}
 
-            //record its distance-cost
-
-            // add its unexplored neighbors
+            // add its unexplored neighbors and update their gVals
+            current.getConnections().forEach {
+                tile ->
+                if(!World.get(tile).isBFSFrontier()) {
+                    World.update(tile, Directions.BFSFRONTIER)
+                    frontier.addLast(tile)
+                    gVals.set(tile, currentG + 1)
+                }
+            }
         }
-
+        markPath(start, end)
+    }
+    fun markPath(start: Tile, end:Tile) {
+        //Step through the path from end until start
+        var current = end
+        var lowestG = Int.MAX_VALUE
+        var lowestCost = end
+        while(current != start) {
+            World.update(current, current.getProperties() + Directions.BFSINPATH)
+            current.getConnections().forEach { candidateTile ->
+                val candidateG = gVals.get(candidateTile) ?: -1
+                if(candidateTile.isInBounds() && candidateG != -1 && candidateG < lowestG ) {
+                    lowestG = candidateG
+                    lowestCost = candidateTile
+                }
+            }
+            current = lowestCost
+        }
+        World.update(start, start.getProperties() + Directions.BFSINPATH)
     }
-
 }

src/main/kotlin/Main.kt

@@ -16,19 +16,27 @@ class HierarchicalPathfinding {
             }
 
             println("Pathfinding")
+
+            val BFSPathFinderTime = measureTime {
+                BFSPathFinder.generatePath(Tile(0, 0), Tile(n-1, n-1))
+            }
+
+
             val ArrayBackedPathfinderTime = measureTime {
                 ArrayBackedPathfinder.generatePath(Tile(0, 0), Tile(n - 1, (n - 1)))
             }
-
+/*
             val MapBackedPathfinderTime = measureTime {
                 MapBackedPathfinder.generatePath(Tile(0, 0), Tile(n - 1, (n - 1)))
             }
+            */
 
             println(World.toString())
             println(n*n)
             println("Maze build time: ${buildMazeTime.inWholeMilliseconds} ms")
-            println("HashMap-Backed Pathfinder time: ${MapBackedPathfinderTime.inWholeMilliseconds}ms")
+            //println("HashMap-Backed Pathfinder time: ${MapBackedPathfinderTime.inWholeMilliseconds}ms")
             println("Array-Backed Pathfinder time: ${ArrayBackedPathfinderTime.inWholeMilliseconds}ms")
+            println("BFS Pathfinder time: ${BFSPathFinderTime.inWholeMilliseconds}ms")
         }
 
         //Clear the maze of pathfinding markers before running another pathfinding algorithm

src/main/kotlin/World.kt

@@ -34,6 +34,9 @@ object World {
     const val ANSI_CYAN = "\u001B[36m"
     const val ANSI_WHITE = "\u001B[37m"
 
+    fun update(tile: Tile, dir: Directions) {
+        update(tile, get(tile) + dir)
+    }
 
     fun update(tile: Tile, to: TileProperties) {
        tiles.set(tile, to)
@@ -74,7 +77,7 @@ object World {
         for (y in 0..sizeY - 1) {
             //Upper line: Print each tile, print right-hand connections
             for (x in 0..sizeX - 1) {
-                if(get(Tile(x, y)).connections and(INPATH.dir) != 0)
+                if(get(Tile(x, y)).connections and(INPATH.dir+BFSINPATH.dir) != 0)
                     inPath = true
                 else if (get(Tile(x, y)).connections and(FRONTIER.dir) != 0)
                     checked = true

src/main/kotlin/data/Tile.kt

@@ -5,6 +5,8 @@ import technology.zim.World
 //Tile is a ULong that represents the X,Y coordinates of a Tile
 //Contains functions necessary for accessing and manipulating Tiles
 
+//TODO: Untangle visited maths
+
 @JvmInline
 value class Tile(private val value: ULong) {
 
@@ -40,6 +42,7 @@ value class Tile(private val value: ULong) {
         return Directions.convertModifier(Tile(otherTile.x() - this.x(), otherTile.y() - this.y()).value)
     }
 
+    //Get adjacent tiles for Prim's Algorithm
     fun getAdjacentTiles(explored:Boolean): Set<Tile> {
         val adj = mutableSetOf<Tile>()
         val dirs = Directions.ALL
@@ -111,6 +114,7 @@ value class Tile(private val value: ULong) {
         return "<" + x() + ", " + y() + ">"
     }
 
+    //Get connections for pathfinding algorithms
     fun getConnections(): Set<Tile> {
         val connections = mutableSetOf<Tile>()
         val properties = getProperties()

src/main/kotlin/data/TileProperties.kt

@@ -58,6 +58,10 @@ value class TileProperties(val connections: Int) {
         return connections and(MANIFEST.dir) == MANIFEST.dir
     }
 
+    fun isBFSFrontier(): Boolean {
+        return connections and(BFSFRONTIER.dir) == BFSFRONTIER.dir
+    }
+
     override fun toString():String {
         val ret = StringBuilder()
         if(isWest()) {