From df36227fe49d9e82bc5899648242fffdb503fb8a Mon Sep 17 00:00:00 2001
From: Leijurv <leijurv@gmail.com>
Date: Fri, 3 Aug 2018 00:50:45 -0400
Subject: [PATCH] started on path finder porting

---
 .../pathing/calc/AbstractNodeCostSearch.java  | 74 +++++++++++++++++++
 .../bot/pathing/calc/IPathFinder.java         | 42 +++++++++++
 2 files changed, 116 insertions(+)
 create mode 100644 src/main/java/baritone/bot/pathing/calc/AbstractNodeCostSearch.java
 create mode 100644 src/main/java/baritone/bot/pathing/calc/IPathFinder.java

diff --git a/src/main/java/baritone/bot/pathing/calc/AbstractNodeCostSearch.java b/src/main/java/baritone/bot/pathing/calc/AbstractNodeCostSearch.java
new file mode 100644
index 00000000..6943fc55
--- /dev/null
+++ b/src/main/java/baritone/bot/pathing/calc/AbstractNodeCostSearch.java
@@ -0,0 +1,74 @@
+package baritone.bot.pathing.calc;
+
+import baritone.bot.pathing.goals.Goal;
+import net.minecraft.util.math.BlockPos;
+
+import java.util.HashMap;
+
+public abstract class AbstractNodeCostSearch implements IPathFinder {
+
+    //TODO this shouldn't be necessary!!
+    public static AbstractNodeCostSearch currentlyRunning = null;
+
+
+    protected final BlockPos start;
+    protected final Goal goal;
+    protected final HashMap<BlockPos, PathNode> map;
+    protected PathNode startNode;
+    protected PathNode mostRecentConsidered;
+    protected PathNode[] bestSoFar;
+    private volatile boolean isFinished;
+
+    /**
+     * This is really complicated and hard to explain. I wrote a comment in the old version of MineBot but it was so
+     * long it was easier as a Google Doc (because I could insert charts).
+     * https://docs.google.com/document/d/1WVHHXKXFdCR1Oz__KtK8sFqyvSwJN_H4lftkHFgmzlc/edit
+     */
+    protected static final double[] COEFFICIENTS = {1.5, 2, 2.5, 3, 4, 5, 10};
+
+    public AbstractNodeCostSearch(BlockPos start, Goal goal) {
+        this.start = start;
+        this.goal = goal;
+        this.map = new HashMap<>();
+    }
+
+    public synchronized IPath calculatePath() {
+        if (isFinished) {
+            throw new IllegalStateException("Unable to re-use path finder");
+        }
+        IPath path = calculate();
+        isFinished = true;
+        return path;
+    }
+
+    protected abstract IPath calculate();
+
+    @Override
+    public boolean isFinished() {
+        return isFinished;
+    }
+
+    @Override
+    public Goal getGoal() {
+        return goal;
+    }
+
+    @Override
+    public BlockPos getStart() {
+        return start;
+    }
+
+
+    @Override
+    public Path bestPathSoFar() {
+        if (startNode == null || bestSoFar[0] == null) {
+            return null;
+        }
+        return new Path(startNode, bestSoFar[0], goal);
+    }
+
+    @Override
+    public Path pathToMostRecentNodeConsidered() {
+        return mostRecentConsidered == null ? null : new Path(startNode, mostRecentConsidered, goal);
+    }
+}
diff --git a/src/main/java/baritone/bot/pathing/calc/IPathFinder.java b/src/main/java/baritone/bot/pathing/calc/IPathFinder.java
new file mode 100644
index 00000000..2e366850
--- /dev/null
+++ b/src/main/java/baritone/bot/pathing/calc/IPathFinder.java
@@ -0,0 +1,42 @@
+package baritone.bot.pathing.calc;
+
+import baritone.bot.pathing.goals.Goal;
+import net.minecraft.util.math.BlockPos;
+
+public interface IPathFinder {
+    BlockPos getStart();
+
+    Goal getGoal();
+
+    /**
+     * Calculate the path in full. Will take several seconds.
+     *
+     * @return the final path
+     */
+    IPath calculatePath();
+
+    /**
+     * Intended to be called concurrently with calculatePath from a different thread to tell if it's finished yet
+     *
+     * @return
+     */
+    boolean isFinished();
+
+    /**
+     * Called for path rendering. Returns a path to the most recent node popped from the open set and considered.
+     *
+     * @return the temporary path
+     */
+    IPath pathToMostRecentNodeConsidered();
+
+    /**
+     * The best path so far, according to the most forgiving coefficient heuristic (the reason being that that path is
+     * most likely to represent the true shape of the path to the goal, assuming it's within a possible cost heuristic.
+     * That's almost always a safe assumption, but in the case of a nearly impossible path, it still works by providing
+     * a theoretically plausible but practically unlikely path)
+     *
+     * @return the temporary path
+     */
+    IPath bestPathSoFar();
+
+}