early commit of collision detection for fastJ physics

src/main/java/module-info.java

@@ -114,4 +114,6 @@
     exports tech.fastj.animation.sprite.event;
     exports tech.fastj.gameloop;
     exports tech.fastj.gameloop.event;
+
+    exports tech.fastj.physics;
 }

src/main/java/tech/fastj/physics/Collider.java

@@ -0,0 +1,5 @@
+package tech.fastj.physics;
+
+public abstract class Collider {
+    public abstract boolean checkCollision(Collider other);
+}

src/main/java/tech/fastj/physics/CollisionManager.java

@@ -0,0 +1,24 @@
+package tech.fastj.physics;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class CollisionManager {
+    private List<Collider> colliders = new ArrayList<>();
+
+    public void addCollider(Collider collider) {
+        colliders.add(collider);
+    }
+
+    public boolean checkCollisions() {
+        for (int i = 0; i < colliders.size(); i++) {
+            for (int j = i + 1; j < colliders.size(); j++) {
+                if (colliders.get(i).checkCollision(colliders.get(j))) {
+                    System.out.println("Collision detected between collider " + i + " and collider " + j);
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+}

src/main/java/tech/fastj/physics/RectangleCollider.java

@@ -0,0 +1,23 @@
+package tech.fastj.physics;
+
+import java.awt.geom.Rectangle2D;
+
+
+public class RectangleCollider extends Collider {
+    private final Rectangle2D shape;
+
+    public RectangleCollider(Rectangle2D shape) {
+        this.shape = shape;
+    }
+
+    @Override
+    public boolean checkCollision(Collider other) {
+        if (other instanceof RectangleCollider) {
+            RectangleCollider otherRectangle = (RectangleCollider) other;
+
+
+            return shape.intersects(otherRectangle.shape);
+        }
+        return false;
+    }
+}

src/test/java/unittest/testcases/physics/CollisionManagerTests.java

@@ -0,0 +1,39 @@
+package unittest.testcases.physics;
+
+import org.junit.jupiter.api.Test;
+import java.awt.geom.Rectangle2D;
+import tech.fastj.physics.RectangleCollider;
+import tech.fastj.physics.CollisionManager;
+
+public class CollisionManagerTests {
+
+    @Test
+    void testCollisionDetection() {
+
+        RectangleCollider collider1 = new RectangleCollider(new Rectangle2D.Double(0, 0, 50, 50));
+        RectangleCollider collider2 = new RectangleCollider(new Rectangle2D.Double(25, 25, 50, 50));
+
+
+        CollisionManager collisionManager = new CollisionManager();
+        collisionManager.addCollider(collider1);
+        collisionManager.addCollider(collider2);
+
+
+        collisionManager.checkCollisions();
+    }
+
+    @Test
+    void testNoCollision() {
+
+        RectangleCollider collider1 = new RectangleCollider(new Rectangle2D.Double(0, 0, 50, 50));
+        RectangleCollider collider2 = new RectangleCollider(new Rectangle2D.Double(100, 100, 50, 50));
+
+
+        CollisionManager collisionManager = new CollisionManager();
+        collisionManager.addCollider(collider1);
+        collisionManager.addCollider(collider2);
+
+
+        collisionManager.checkCollisions();
+    }
+}