From f463f086424fde8f8d82d5beb98fafc872c04cd3 Mon Sep 17 00:00:00 2001
From: Vladimir Olteanu <vladimir.olteanu@cs.pub.ro>
Date: Thu, 7 Jul 2022 09:45:38 +0300
Subject: [PATCH] Refactor FindClosestValidPosition to use Crawl

---
 Source/engine/path.cpp | 138 ++---------------------------------------
 1 file changed, 6 insertions(+), 132 deletions(-)

diff --git a/Source/engine/path.cpp b/Source/engine/path.cpp
index 3e31df181..3505cc593 100644
--- a/Source/engine/path.cpp
+++ b/Source/engine/path.cpp
@@ -8,6 +8,7 @@
 #include <array>
 
 #include "levels/gendung.h"
+#include "lighting.h"
 #include "objects.h"
 
 namespace devilution {
@@ -435,139 +436,12 @@ bool path_solid_pieces(Point startPosition, Point destinationPosition)
 
 std::optional<Point> FindClosestValidPosition(const std::function<bool(Point)> &posOk, Point startingPosition, unsigned int minimumRadius, unsigned int maximumRadius)
 {
-	if (minimumRadius > maximumRadius) {
-		return {}; // No valid search space with the given params.
-	}
-
-	if (minimumRadius == 0U) {
-		if (posOk(startingPosition)) {
-			return startingPosition;
-		}
-	}
-
-	if (minimumRadius <= 1U && maximumRadius >= 1U) {
-		// unrolling the case for radius 1 to save having to guard the corner check in the loop below.
-
-		Point candidatePosition = startingPosition + Direction::SouthWest;
-		if (posOk(candidatePosition)) {
-			return candidatePosition;
-		}
-		candidatePosition = startingPosition + Direction::NorthEast;
-		if (posOk(candidatePosition)) {
-			return candidatePosition;
-		}
-
-		candidatePosition = startingPosition + Direction::NorthWest;
-		if (posOk(candidatePosition)) {
-			return candidatePosition;
-		}
-
-		candidatePosition = startingPosition + Direction::SouthEast;
-		if (posOk(candidatePosition)) {
+	return Crawl(minimumRadius, maximumRadius, [&](auto displacement) -> std::optional<Point> {
+		Point candidatePosition = startingPosition + displacement;
+		if (posOk(candidatePosition))
 			return candidatePosition;
-		}
-	}
-
-	if (maximumRadius >= 2U) {
-		for (int i = static_cast<int>(std::max(minimumRadius, 2U)); i <= static_cast<int>(std::min(maximumRadius, 50U)); i++) {
-			int x = 0;
-			int y = i;
-
-			// special case the checks when x == 0 to save checking the same tiles twice
-			Point candidatePosition = startingPosition + Displacement { x, y };
-			if (posOk(candidatePosition)) {
-				return candidatePosition;
-			}
-			candidatePosition = startingPosition + Displacement { x, -y };
-			if (posOk(candidatePosition)) {
-				return candidatePosition;
-			}
-
-			while (x < i - 1) {
-				x++;
-
-				candidatePosition = startingPosition + Displacement { -x, y };
-				if (posOk(candidatePosition)) {
-					return candidatePosition;
-				}
-
-				candidatePosition = startingPosition + Displacement { x, y };
-				if (posOk(candidatePosition)) {
-					return candidatePosition;
-				}
-
-				candidatePosition = startingPosition + Displacement { -x, -y };
-				if (posOk(candidatePosition)) {
-					return candidatePosition;
-				}
-
-				candidatePosition = startingPosition + Displacement { x, -y };
-				if (posOk(candidatePosition)) {
-					return candidatePosition;
-				}
-			}
-
-			// special case for inset corners
-			y--;
-			candidatePosition = startingPosition + Displacement { -x, y };
-			if (posOk(candidatePosition)) {
-				return candidatePosition;
-			}
-
-			candidatePosition = startingPosition + Displacement { x, y };
-			if (posOk(candidatePosition)) {
-				return candidatePosition;
-			}
-
-			candidatePosition = startingPosition + Displacement { -x, -y };
-			if (posOk(candidatePosition)) {
-				return candidatePosition;
-			}
-
-			candidatePosition = startingPosition + Displacement { x, -y };
-			if (posOk(candidatePosition)) {
-				return candidatePosition;
-			}
-			x++;
-
-			while (y > 0) {
-				candidatePosition = startingPosition + Displacement { -x, y };
-				if (posOk(candidatePosition)) {
-					return candidatePosition;
-				}
-
-				candidatePosition = startingPosition + Displacement { x, y };
-				if (posOk(candidatePosition)) {
-					return candidatePosition;
-				}
-
-				candidatePosition = startingPosition + Displacement { -x, -y };
-				if (posOk(candidatePosition)) {
-					return candidatePosition;
-				}
-
-				candidatePosition = startingPosition + Displacement { x, -y };
-				if (posOk(candidatePosition)) {
-					return candidatePosition;
-				}
-
-				y--;
-			}
-
-			// as above, special case for y == 0
-			candidatePosition = startingPosition + Displacement { -x, y };
-			if (posOk(candidatePosition)) {
-				return candidatePosition;
-			}
-
-			candidatePosition = startingPosition + Displacement { x, y };
-			if (posOk(candidatePosition)) {
-				return candidatePosition;
-			}
-		}
-	}
-
-	return {};
+		return {};
+	});
 }
 
 #ifdef BUILD_TESTING