cherry pick refactor

src/main/java/baritone/pathing/calc/IPathFinder.java

@@ -0,0 +1,67 @@
+/*
+ * This file is part of Baritone.
+ *
+ * Baritone is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Baritone is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Baritone.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package baritone.pathing.calc;
+
+import baritone.pathing.goals.Goal;
+import baritone.pathing.path.IPath;
+import net.minecraft.util.math.BlockPos;
+
+import java.util.Optional;
+
+/**
+ * Generic path finder interface
+ *
+ * @author leijurv
+ */
+public interface IPathFinder {
+
+    BlockPos getStart();
+
+    Goal getGoal();
+
+    /**
+     * Calculate the path in full. Will take several seconds.
+     *
+     * @return The final path
+     */
+    Optional<IPath> calculate();
+
+    /**
+     * Intended to be called concurrently with calculatePath from a different thread to tell if it's finished yet
+     *
+     * @return Whether or not this finder is finished
+     */
+    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
+     */
+    Optional<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
+     */
+    Optional<IPath> bestPathSoFar();
+}