Fix pathfinding

.gitignore

@@ -1,2 +1,5 @@
 last_light
 last_light.exe
+
+*.prof
+__debug_bin*

engine/pathfinding.go

@@ -1,7 +1,6 @@
 package engine
 
 import (
-	"math"
 	"slices"
 )
 
@@ -10,14 +9,12 @@ type pathNode struct {
 
 	parent *pathNode
 
-	g float64 // distance between current node and start node
+	g int // distance between current node and start node
-	h float64 // heuristic - squared distance from current node to end node
+	h int // heuristic - squared distance from current node to end node
-	f float64 // total cost of this node
+	f int // total cost of this node
 }
 
-func FindPath(from Position, to Position, maxDistance int, isPassable func(x, y int) bool) *Path {
+func FindPath(from Position, to Position, isPassable func(x, y int) bool) *Path {
-	maxDistanceSquared := math.Pow(float64(maxDistance), 2)
-
 	var openList = make([]*pathNode, 0)
 	var closedList = make([]*pathNode, 0)
 
@@ -32,6 +29,7 @@ func FindPath(from Position, to Position, maxDistance int, isPassable func(x, y
 	var lastNode *pathNode
 
 	for {
+
 		if len(openList) == 0 {
 			break
 		}
@@ -87,13 +85,8 @@ func FindPath(from Position, to Position, maxDistance int, isPassable func(x, y
 			}
 
 			child.g = currentNode.g + 1
-
-			if child.g > maxDistanceSquared {
-				continue
-			}
-
 			child.h = to.DistanceSquared(child.pos)
-			child.f = float64(child.g) + child.f
+			child.f = child.g + child.h
 
 			// If child is already contained in openList, and has lower g
 			if slices.ContainsFunc(openList, func(el *pathNode) bool { return el.pos.Equals(child.pos) && child.g > el.g }) {

engine/pathfinding_test.go

@@ -0,0 +1,32 @@
+package engine
+
+import (
+	"log"
+	"testing"
+)
+
+func BenchmarkPathfinding(b *testing.B) {
+	path := FindPath(
+		PositionAt(0, 0),
+		PositionAt(16, 16),
+		func(x, y int) bool {
+			if x > 6 && x <= 16 && y == 10 {
+				return false
+			}
+
+			if x < 0 || y < 0 {
+				return false
+			}
+
+			if x > 16 || y > 16 {
+				return false
+			}
+
+			return true
+		},
+	)
+
+	if path == nil {
+		log.Fatalf("No path could be found")
+	}
+}

engine/util.go

@@ -44,12 +44,12 @@ func (p Position) XY() (int, int) {
 	return p.x, p.y
 }
 
-func (p Position) DistanceSquared(pos Position) float64 {
+func (p Position) DistanceSquared(pos Position) int {
-	return float64((pos.x-p.x)*(pos.x-p.x) + (pos.y-p.y)*(pos.y-p.y))
+	return (pos.x-p.x)*(pos.x-p.x) + (pos.y-p.y)*(pos.y-p.y)
 }
 
-func (p Position) Distance(pos Position) float64 {
+func (p Position) Distance(pos Position) int {
-	return math.Sqrt(p.DistanceSquared(pos))
+	return int(math.Floor(math.Sqrt(float64(p.DistanceSquared(pos)))))
 }
 
 func (p Position) Equals(other Position) bool {

game/state/playing_state.go

@@ -181,14 +181,14 @@ func (ps *PlayingState) PickUpItemUnderPlayer() {
 
 func (ps *PlayingState) CalcPathToPlayerAndMove() {
 	distanceToPlayer := ps.someNPC.Position().Distance(ps.player.Position())
-	if distanceToPlayer > 16 {
+
+	if distanceToPlayer > 20 {
 		return
 	}
 
 	pathToPlayer := engine.FindPath(
 		ps.someNPC.Position(),
 		ps.player.Position(),
-		16,
 		func(x, y int) bool {
 			if x == ps.player.Position().X() && y == ps.player.Position().Y() {
 				return true