From 2c4155b674d93c0075df8936f86f526923310e86 Mon Sep 17 00:00:00 2001
From: Dennis Eichhorn <spl1nes.com@googlemail.com>
Date: Wed, 4 Sep 2019 21:39:29 +0200
Subject: [PATCH] streamline heuristic by using metrics implementation

---
 Algorithm/PathFinding/AStar.php           |  2 +-
 Algorithm/PathFinding/Heuristic.php       | 47 +++++++----------------
 Algorithm/PathFinding/HeuristicType.php   | 11 ++++--
 Algorithm/PathFinding/JumpPointSearch.php |  4 +-
 Algorithm/PathFinding/Node.php            |  5 +++
 5 files changed, 28 insertions(+), 41 deletions(-)

diff --git a/Algorithm/PathFinding/AStar.php b/Algorithm/PathFinding/AStar.php
index 52f8f9fe7..59be87f08 100644
--- a/Algorithm/PathFinding/AStar.php
+++ b/Algorithm/PathFinding/AStar.php
@@ -66,7 +66,7 @@ class JumpPointSearch implements PathFinderInterface
 
                 if (!$neighbor->isOpened() || $ng < $neighbor->getG()) {
                     $neighbor->setG($ng);
-                    $neighbor->setH($neighbor->getG() ?? $neighbor->getWeight() * Heuristic::heuristic($neighbor, $endNode, $heuristic));
+                    $neighbor->setH($neighbor->getG() ?? $neighbor->getWeight() * Heuristic::heuristic($neighbor->getCoordinates(), $endNode->getCoordinates(), $heuristic));
                     $neighbor->setF($neighbor->getG() + $neighbor->getH());
                     $neighbor->setParent($node);
 
diff --git a/Algorithm/PathFinding/Heuristic.php b/Algorithm/PathFinding/Heuristic.php
index 0e8f259c5..8e5ae5b8e 100644
--- a/Algorithm/PathFinding/Heuristic.php
+++ b/Algorithm/PathFinding/Heuristic.php
@@ -14,6 +14,8 @@ declare(strict_types=1);
 
 namespace phpOMS\Algorithm\PathFinding;
 
+use phpOMS\Math\Topology\Metrics2D;
+
 /**
  * Node on grid.
  *
@@ -24,45 +26,22 @@ namespace phpOMS\Algorithm\PathFinding;
  */
 class Heuristic
 {
-    public static function heuristic(Node $node1, Node $node2, int $heuristic) : float
+    public static function heuristic(array $node1, array $node2, int $heuristic) : float
     {
         if ($heuristic === HeuristicType::MANHATTAN) {
-            return self::manhattan($node1, $node2);
+            return Metrics2D::manhattan($node1, $node2);
         } elseif ($heuristic === HeuristicType::EUCLIDEAN) {
-            return self::euclidean($node1, $node2);
+            return Metrics2D::euclidean($node1, $node2);
         } elseif ($heuristic === HeuristicType::OCTILE) {
-            return self::octile($node1, $node2);
+            return Metrics2D::octile($node1, $node2);
+        } elseif ($heuristic === HeuristicType::MINKOWSKI) {
+            return Metrics2D::minkowski($node1, $node2, 1);
+        } elseif ($heuristic === HeuristicType::CANBERRA) {
+            return Metrics2D::canberra($node1, $node2);
+        } elseif ($heuristic === HeuristicType::BRAY_CURTIS) {
+            return Metrics2D::brayCurtis($node1, $node2);
         }
 
-        return self::chebyshev($node1, $node2);
-    }
-
-    public static function manhattan(Node $node1, Node $node2) : float
-    {
-        return \abs($node1->getX() - $node2->getX()) + \abs($node1->getY() - $node2->getY());
-    }
-
-    public static function euclidean(Node $node1, Node $node2) : float
-    {
-        $dx = \abs($node1->getX() - $node2->getX());
-        $dy = \abs($node1->getY() - $node2->getY());
-
-        return \sqrt($dx * $dx + $dy * $dy);
-    }
-
-    public static function octile(Node $node1, Node $node2) : float
-    {
-        $dx = \abs($node1->getX() - $node2->getX());
-        $dy = \abs($node1->getY() - $node2->getY());
-
-        return $dx < $dy ? (\sqrt(2) - 1) * $dx + $dy : (\sqrt(2) - 1) * $dy + $dx;
-    }
-
-    public static function chebyshev(Node $node1, Node $node2) : float
-    {
-        return \max(
-            \abs($node1->getX() - $node2->getX()),
-            \abs($node1->getY() - $node2->getY())
-        );
+        return Metrics2D::chebyshev($node1, $node2);
     }
 }
diff --git a/Algorithm/PathFinding/HeuristicType.php b/Algorithm/PathFinding/HeuristicType.php
index 73aaf483a..2d51434ad 100644
--- a/Algorithm/PathFinding/HeuristicType.php
+++ b/Algorithm/PathFinding/HeuristicType.php
@@ -26,8 +26,11 @@ use phpOMS\Stdlib\Base\Enum;
  */
 abstract class HeuristicType extends Enum
 {
-    public const MANHATTAN = 1;
-    public const EUCLIDEAN = 2;
-    public const OCTILE    = 4;
-    public const CHEBYSHEV = 8;
+    public const MANHATTAN   = 1;
+    public const EUCLIDEAN   = 2;
+    public const OCTILE      = 4;
+    public const CHEBYSHEV   = 8;
+    public const MINKOWSKI   = 16;
+    public const CANBERRA    = 32;
+    public const BRAY_CURTIS = 64;
 }
diff --git a/Algorithm/PathFinding/JumpPointSearch.php b/Algorithm/PathFinding/JumpPointSearch.php
index 0b7cdc28c..11958494c 100644
--- a/Algorithm/PathFinding/JumpPointSearch.php
+++ b/Algorithm/PathFinding/JumpPointSearch.php
@@ -79,12 +79,12 @@ class JumpPointSearch implements PathFinderInterface
                 continue;
             }
 
-            $d  = Heuristic::octile($node, $jumpPoint);
+            $d  = Heuristic::heuristic($node->getCoordinates(), $jumpPoint->getCoordinates(), HeuristicType::OCTILE);
             $ng = $node->getG() + $d;
 
             if (!$jumpPoint->isOpened() || $ng < $jumpPoint->getG()) {
                 $jumpPoint->setG($ng);
-                $jumpPoint->setH($jumpPoint->getH() ?? Heuristic::heuristic($jumpPoint, $endNode, $heuristic));
+                $jumpPoint->setH($jumpPoint->getH() ?? Heuristic::heuristic($jumpPoint->getCoordinates(), $endNode->getCoordinates(), $heuristic));
                 $jumpPoint->setF($jumpPoint->getG() + $jumpPoint->getH());
                 $jumpPoint->setParent($node);
 
diff --git a/Algorithm/PathFinding/Node.php b/Algorithm/PathFinding/Node.php
index 916612701..7c8867dff 100644
--- a/Algorithm/PathFinding/Node.php
+++ b/Algorithm/PathFinding/Node.php
@@ -72,4 +72,9 @@ class Node
     {
         return $this->x === $node->getX() && $this->y === $node->getY();
     }
+
+    public function getCoordinates() : array
+    {
+        return ['x' => $this->x, 'y' => $this->y];
+    }
 }