docs/model-module (#13)

* docs(model/entities): Documentation for entities and items

Adds documentation to the following entity and item classes
    - Entity
    - EntityUtils
    - Items

Did not add documentation for Ghost entity and Pacman entity,
since the class is not done yet.

* fix/small-fixes (#14)

* fix(model/entities): entites start in center of tile
* style(pacman): It should be width and height, not height and width.
* refactor(view): Changing setting of background color

3 files changed, 142 insertions, 5 deletions

diff --git a/pacman/model/src/main/java/com/gr15/pacman/model/entities/Entity.java b/pacman/model/src/main/java/com/gr15/pacman/model/entities/Entity.java
index 0792219..8d2a176 100644
--- a/pacman/model/src/main/java/com/gr15/pacman/model/entities/Entity.java
+++ b/pacman/model/src/main/java/com/gr15/pacman/model/entities/Entity.java
@@ -4,7 +4,26 @@ import com.gr15.pacman.model.Board;
 import com.gr15.pacman.model.Position;
 
 /**
- * Entity
+ * Represents an abstract entity with a position
+ * and collision radius on a game board.
+ *
+ * <p>
+ * This class stores both tile-based {@link Position}
+ * and fine-grained sub-tile coordinates
+ * to allow smooth movement within and across grid tiles.
+ * </p>
+ *
+ * <p>
+ * The full world coordinates are computed by combining
+ * the integer {@code Position} with
+ * {@code subTileX} and {@code subTileY}, allowing sub-tile precision
+ * useful for animation or collision detection.
+ * </p>
+ *
+ * <p>
+ * Subclasses must implement the {@code move} method
+ * to define entity-specific behavior over time.
+ * </p>
  */
 public abstract class Entity {
 
@@ -16,23 +35,101 @@ public abstract class Entity {
 
     public enum Direction { UP, DOWN, LEFT, RIGHT, NONE };
     
+    /**
+     * Constructs an Entity with the specified starting position and radius.
+     *
+     * @param startPos The initial tile-based position of the entity.
+     * @param radius The collision radius of the entity.
+     * @throws IllegalArgumentException if any parameter is invalid:
+     *         - startPos is null
+     *         - radius is less than or equal to zero
+     */
     public Entity(Position startPos, double radius) {
+        if (startPos == null) { throw new IllegalArgumentException("startPos cannot be null"); }
+        if (radius <= 0) { throw new IllegalArgumentException("radius must be positive"); }
         this.radius = radius;
         this.position = startPos;
     }
 
+    /**
+     * Updates the entity's position based on game logic and elapsed time.
+     *
+     * @param board The board the entity is moving on.
+     * @param deltaSeconds The time elapsed since the last update, in seconds.
+     */
     public abstract void move(Board board, double deltaSeconds);
 
-    /* Getters and setters */
+
+                            /* Getters */
+    /**
+     * Gets the tile-based position of the entity.
+     *
+     * @return The current tile position.
+     */
     public Position getPosition() { return this.position; }
+
+    /**
+     * Gets the entity's sub-tile X offset.
+     *
+     * @return The sub-tile X coordinate.
+     */
     public float getSubTileX() { return this.subTileX; }
+
+    /**
+     * Gets the entity's sub-tile Y offset.
+     *
+     * @return The sub-tile Y coordinate.
+     */
     public float getSubTileY() { return this.subTileY; }
+
+    /**
+     * Gets the radius of the entity.
+     *
+     * @return The collision radius.
+     */
     public double getRadius() { return this.radius; }
+
+    /**
+     * Gets the full X coordinate, including sub-tile offset.
+     *
+     * @return The entity's X position as a double.
+     */
     public double getPositionX() { return position.x() + subTileX; }
+
+    /**
+     * Gets the full Y coordinate, including sub-tile offset.
+     *
+     * @return The entity's Y position as a double.
+     */
     public double getPositionY() { return position.y() + subTileY; }
 
+
+                            /* Setters */
+    /**
+     * Sets the entity's tile-based position.
+     *
+     * @param newPos The new tile position to set.
+     */
     public void setPosition(Position newPos) { this.position = newPos; }
+
+    /**
+     * Sets the entity's sub-tile X offset.
+     *
+     * @param newX The new sub-tile X coordinate.
+     */
     public void setSubTileX(float newX) { this.subTileX = newX; }
+
+    /**
+     * Sets the entity's sub-tile Y offset.
+     *
+     * @param newY The new sub-tile Y coordinate.
+     */
     public void setSubTileY(float newY) { this.subTileY = newY; }
+
+    /**
+     * Sets the entity's collision radius.
+     *
+     * @param newRad The new radius value.
+     */
     public void setRadius(double newRad) { this.radius = newRad; }
 }
diff --git a/pacman/model/src/main/java/com/gr15/pacman/model/entities/EntityUtils.java b/pacman/model/src/main/java/com/gr15/pacman/model/entities/EntityUtils.java
index fd52acb..355a6f4 100644
--- a/pacman/model/src/main/java/com/gr15/pacman/model/entities/EntityUtils.java
+++ b/pacman/model/src/main/java/com/gr15/pacman/model/entities/EntityUtils.java
@@ -1,11 +1,29 @@
 package com.gr15.pacman.model.entities;
 
 /**
- * Util
+ * Utility class providing helper methods 
+ * for working with {@link Entity} objects.
+ * 
+ * <p>
+ * This class includes methods for calculating distances
+ * and detecting collisions
+ * between entities in the game world,
+ * taking into account their sub-tile positions and radii.
+ * </p>
+ *
+ * <p>This class is final and cannot be instantiated.</p>
  */
+
 public final class EntityUtils {
 
-    
+    /**
+     * Calculates the Euclidean distance between
+     * two entities based on their position and sub-tile offsets.
+     *
+     * @param arg0 the first entity.
+     * @param arg1 the second entity.
+     * @return the distance between the centers of the two entities.
+     */
     public static double distance(Entity arg0, Entity arg1) {
         double arg0X = arg0.getPosition().x() + arg0.getSubTileX();
         double arg0Y = arg0.getPosition().y() + arg0.getSubTileY();
@@ -15,6 +33,14 @@ public final class EntityUtils {
         return Math.hypot(arg0X - arg1X, arg0Y - arg1Y);
     }
     
+    /**
+     * Determines whether two entities have collided
+     * based on the distance between their centers and their combined radii.
+     *
+     * @param arg0 the first entity.
+     * @param arg1 the second entity.
+     * @return true if the entities have collided; false otherwise.
+     */
     public static boolean hasCollided(Entity arg0, Entity arg1) {
         double arg0X = arg0.getPosition().x() + arg0.getSubTileX();
         double arg0Y = arg0.getPosition().y() + arg0.getSubTileY();
diff --git a/pacman/model/src/main/java/com/gr15/pacman/model/entities/Items.java b/pacman/model/src/main/java/com/gr15/pacman/model/entities/Items.java
index 3b09a54..d4ecc13 100644
--- a/pacman/model/src/main/java/com/gr15/pacman/model/entities/Items.java
+++ b/pacman/model/src/main/java/com/gr15/pacman/model/entities/Items.java
@@ -1,3 +1,17 @@
 package com.gr15.pacman.model.entities;
 
-public enum Items { PELLET, POWER_PELLET };
+/**
+ * Represents the different types of items that can appear in the game.
+ */
+public enum Items {
+
+    /**
+     * A standard pellet.
+     */
+    PELLET,
+
+    /**
+     * A power pellet.
+     */
+    POWER_PELLET
+};