Refactor coordinate system

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

lib/classes/coordinate_2d.dart

@@ -0,0 +1,54 @@
+import 'dart:math' as math;
+
+/// A robust, immutable 2D coordinate.
+class Coordinate2D implements Comparable<Coordinate2D> {
+  final double x;
+  final double y;
+
+  const Coordinate2D(this.x, this.y);
+
+  /// Factory for a (0,0) coordinate.
+  static const Coordinate2D zero = Coordinate2D(0.0, 0.0);
+
+  // --- Core Logic ---
+
+  /// Returns the Euclidean distance between this and [other].
+  /// Uses the formula: $$d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}$$
+  double distanceTo(Coordinate2D other) {
+    final dx = x - other.x;
+    final dy = y - other.y;
+    return math.sqrt(dx * dx + dy * dy);
+  }
+
+  /// True if both ordinates are finite (not NaN or Infinity).
+  bool get isValid => x.isFinite && y.isFinite;
+
+  Coordinate2D operator +(Coordinate2D other) =>
+      Coordinate2D(x + other.x, y + other.y);
+  Coordinate2D operator -(Coordinate2D other) =>
+      Coordinate2D(x - other.x, y - other.y);
+  Coordinate2D operator *(double factor) =>
+      Coordinate2D(x * factor, y * factor);
+  Coordinate2D operator /(double divisor) =>
+      Coordinate2D(x / divisor, y / divisor);
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is Coordinate2D &&
+          runtimeType == other.runtimeType &&
+          x == other.x &&
+          y == other.y;
+
+  @override
+  int get hashCode => Object.hash(x, y);
+
+  @override
+  int compareTo(Coordinate2D other) {
+    if (x != other.x) return x.compareTo(other.x);
+    return y.compareTo(other.y);
+  }
+
+  @override
+  String toString() => 'Coordinate($x, $y)';
+}

lib/classes/linear_coordinates.dart

@@ -1 +0,0 @@
-typedef LinearCoordinates = ({double x, double y});

lib/features/entities/enemies/brown_guard.dart

@@ -1,6 +1,6 @@
 import 'dart:math' as math;
 
-import 'package:wolf_dart/classes/linear_coordinates.dart';
+import 'package:wolf_dart/classes/coordinate_2d.dart';
 import 'package:wolf_dart/features/entities/enemies/enemy.dart';
 import 'package:wolf_dart/features/entities/entity.dart';
 
@@ -56,19 +56,20 @@ class BrownGuard extends Enemy {
   @override
   void update({
     required int elapsedMs,
-    required LinearCoordinates player,
+    required Coordinate2D playerPosition,
     required bool Function(int x, int y) isWalkable,
     required void Function(int damage) onDamagePlayer,
   }) {
     // 1. Wake up logic
-    if (state == EntityState.idle && hasLineOfSight(player, isWalkable)) {
+    if (state == EntityState.idle &&
+        hasLineOfSight(playerPosition, isWalkable)) {
       state = EntityState.patrolling;
       lastActionTime = elapsedMs;
     }
 
     // 2. Pre-calculate angles (needed for almost all states)
-    double dx = player.x - x;
-    double dy = player.y - y;
+    double dx = playerPosition.x - x;
+    double dy = playerPosition.y - y;
     double distance = math.sqrt(dx * dx + dy * dy);
     double angleToPlayer = math.atan2(dy, dx);
 
@@ -107,7 +108,7 @@ class BrownGuard extends Enemy {
         spriteIndex = 58 + (walkFrame * 8) + octant;
         // Shooting transition
         if (distance < 5.0 && elapsedMs - lastActionTime > 2000) {
-          if (hasLineOfSight(player, isWalkable)) {
+          if (hasLineOfSight(playerPosition, isWalkable)) {
             state = EntityState.shooting;
             lastActionTime = elapsedMs;
             _hasFiredThisCycle = false;

lib/features/entities/enemies/dog.dart

@@ -1,6 +1,6 @@
 import 'dart:math' as math;
 
-import 'package:wolf_dart/classes/linear_coordinates.dart';
+import 'package:wolf_dart/classes/coordinate_2d.dart';
 import 'package:wolf_dart/features/entities/enemies/enemy.dart';
 import 'package:wolf_dart/features/entities/entity.dart';
 
@@ -49,12 +49,12 @@ class Dog extends Enemy {
   @override
   void update({
     required int elapsedMs,
-    required LinearCoordinates player,
+    required Coordinate2D playerPosition,
     required bool Function(int x, int y) isWalkable,
     required void Function(int damage) onDamagePlayer,
   }) {
     if (state == EntityState.idle) {
-      if (hasLineOfSight(player, isWalkable)) {
+      if (hasLineOfSight(playerPosition, isWalkable)) {
         state = EntityState.patrolling;
         lastActionTime = elapsedMs;
       }
@@ -65,8 +65,8 @@ class Dog extends Enemy {
         state == EntityState.shooting) {
       // "Shooting" here means biting
 
-      double dx = player.x - x;
-      double dy = player.y - y;
+      double dx = playerPosition.x - x;
+      double dy = playerPosition.y - y;
       double distance = math.sqrt(dx * dx + dy * dy);
       double angleToPlayer = math.atan2(dy, dx);
 

lib/features/entities/enemies/enemy.dart

@@ -1,6 +1,6 @@
 import 'dart:math' as math;
 
-import 'package:wolf_dart/classes/linear_coordinates.dart';
+import 'package:wolf_dart/classes/coordinate_2d.dart';
 import 'package:wolf_dart/features/entities/entity.dart';
 
 abstract class Enemy extends Entity {
@@ -58,11 +58,11 @@ abstract class Enemy extends Entity {
 
   // The enemy can now check its own line of sight!
   bool hasLineOfSight(
-    LinearCoordinates player,
+    Coordinate2D playerPosition,
     bool Function(int x, int y) isWalkable,
   ) {
-    double dx = player.x - x;
-    double dy = player.y - y;
+    double dx = playerPosition.x - x;
+    double dy = playerPosition.y - y;
     double distance = math.sqrt(dx * dx + dy * dy);
 
     // 1. FOV Check
@@ -94,7 +94,7 @@ abstract class Enemy extends Entity {
 
   // The weapon asks the enemy if it is unobstructed from the shooter
   bool hasLineOfSightFrom(
-    LinearCoordinates source,
+    Coordinate2D source,
     double sourceAngle,
     double distance,
     bool Function(int x, int y) isWalkable,
@@ -112,7 +112,7 @@ abstract class Enemy extends Entity {
 
   void update({
     required int elapsedMs,
-    required LinearCoordinates player,
+    required Coordinate2D playerPosition,
     required bool Function(int x, int y) isWalkable,
     required void Function(int damage) onDamagePlayer,
   });

lib/features/player/player.dart

@@ -1,6 +1,6 @@
 import 'dart:math' as math;
 
-import 'package:wolf_dart/classes/linear_coordinates.dart';
+import 'package:wolf_dart/classes/coordinate_2d.dart';
 import 'package:wolf_dart/features/entities/collectible.dart';
 import 'package:wolf_dart/features/entities/entity.dart';
 import 'package:wolf_dart/features/weapon/weapon.dart';
@@ -55,7 +55,7 @@ class Player {
   }
 
   // Helper getter to interface with the RaycasterPainter
-  LinearCoordinates get position => (x: x, y: y);
+  Coordinate2D get position => Coordinate2D(x, y);
 
   // --- Weapon Switching & Animation Logic ---
 

lib/features/renderer/renderer.dart

@@ -2,7 +2,7 @@ import 'dart:math' as math;
 
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
-import 'package:wolf_dart/classes/linear_coordinates.dart';
+import 'package:wolf_dart/classes/coordinate_2d.dart';
 import 'package:wolf_dart/classes/matrix.dart';
 import 'package:wolf_dart/features/difficulty/difficulty.dart';
 import 'package:wolf_dart/features/entities/collectible.dart';
@@ -146,7 +146,7 @@ class _WolfRendererState extends State<WolfRenderer>
         pX >= currentLevel[0].length ||
         currentLevel[pY][pX] > 0) {
       double shortestDist = double.infinity;
-      LinearCoordinates nearestSafeSpot = (x: 1.5, y: 1.5);
+      Coordinate2D nearestSafeSpot = Coordinate2D(1.5, 1.5);
 
       for (int y = 0; y < currentLevel.length; y++) {
         for (int x = 0; x < currentLevel[y].length; x++) {
@@ -159,7 +159,7 @@ class _WolfRendererState extends State<WolfRenderer>
 
             if (dist < shortestDist) {
               shortestDist = dist;
-              nearestSafeSpot = (x: safeX, y: safeY);
+              nearestSafeSpot = Coordinate2D(safeX, safeY);
             }
           }
         }
@@ -186,7 +186,7 @@ class _WolfRendererState extends State<WolfRenderer>
 
     // 2. Explicit State Updates
     player.updateWeaponSwitch();
-    _applyMovementAndCollision(movement.dx, movement.dy);
+    _applyMovementAndCollision(movement.x, movement.y);
     _updateEntities(elapsed);
 
     // Explicit reassignment from a pure(r) function
@@ -209,7 +209,7 @@ class _WolfRendererState extends State<WolfRenderer>
   }
 
   // Returns movement deltas instead of modifying class variables
-  ({double dx, double dy}) _processInputs(Duration elapsed) {
+  Coordinate2D _processInputs(Duration elapsed) {
     inputManager.update();
 
     const double moveSpeed = 0.16;
@@ -248,7 +248,7 @@ class _WolfRendererState extends State<WolfRenderer>
       );
     }
 
-    return (dx: dx, dy: dy);
+    return Coordinate2D(dx, dy);
   }
 
   // Now receives dx and dy explicitly
@@ -277,7 +277,7 @@ class _WolfRendererState extends State<WolfRenderer>
       if (entity is Enemy) {
         entity.update(
           elapsedMs: elapsed.inMilliseconds,
-          player: player.position,
+          playerPosition: player.position,
           isWalkable: _isWalkable,
           onDamagePlayer: _takeDamage,
         );

lib/features/weapon/weapon.dart

@@ -1,6 +1,6 @@
 import 'dart:math' as math;
 
-import 'package:wolf_dart/classes/linear_coordinates.dart';
+import 'package:wolf_dart/classes/coordinate_2d.dart';
 import 'package:wolf_dart/features/entities/enemies/enemy.dart';
 import 'package:wolf_dart/features/entities/entity.dart';
 
@@ -83,7 +83,7 @@ abstract class Weapon {
         double threshold = 0.2 / dist;
 
         if (angleDiff.abs() < threshold) {
-          LinearCoordinates source = (x: playerX, y: playerY);
+          Coordinate2D source = Coordinate2D(playerX, playerY);
 
           // Delegate to the enemy to check if it's visible
           if (entity.hasLineOfSightFrom(