Resolve "implement collision detection"

1ffac2c5 · Eli Fjellbirkeland Johannesen · 605babd3 · 1ffac2c5 · 1ffac2c5 · 1ffac2c5
Commit 1ffac2c5 authored 2 years ago by Eli Fjellbirkeland Johannesen
--- a/frontend/core/src/com/game/tankwars/CollisionDetection.java
+++ b/frontend/core/src/com/game/tankwars/CollisionDetection.java
+package com.game.tankwars;
+
+import com.badlogic.gdx.physics.box2d.Body;
+import com.badlogic.gdx.physics.box2d.BodyDef;
+import com.badlogic.gdx.physics.box2d.Contact;
+import com.badlogic.gdx.physics.box2d.ContactImpulse;
+import com.badlogic.gdx.physics.box2d.ContactListener;
+import com.badlogic.gdx.physics.box2d.Fixture;
+import com.badlogic.gdx.physics.box2d.Manifold;
+import com.badlogic.gdx.physics.box2d.World;
+import com.game.tankwars.model.Box2dWorld;
+import com.game.tankwars.model.FixtureData;
+
+public class CollisionDetection implements ContactListener {
+
+    World world;
+
+    public CollisionDetection() {
+        this.world = Box2dWorld.getWorld();
+    }
+
+    @Override
+    public void beginContact(Contact contact) {
+        Fixture fixA = contact.getFixtureA();
+        Fixture fixB = contact.getFixtureB();
+        FixtureData dataA = (FixtureData) fixA.getUserData();
+        FixtureData dataB = (FixtureData) fixB.getUserData();
+
+        if (dataA.getId().equals("userTank") && dataB.getId().equals("bullet")) {
+            System.out.println("The bullet has hit the player's tank");
+            dataB.hasCollided();
+        }
+
+        else if (dataA.getId().equals("opponentTank") && dataB.getId().equals("bullet")) {
+            System.out.println("The bullet has hit the opponent's tank");
+            dataB.hasCollided();
+        }
+
+        else if (dataA.getId().equals("terrain") && dataB.getId().equals("bullet")) {
+            System.out.println("The bullet has hit the ground!");
+            dataB.hasCollided();
+
+        }
+    }
+
+    @Override
+    public void endContact(Contact contact) {
+
+    }
+
+    @Override
+    public void preSolve(Contact contact, Manifold oldManifold) {
+
+    }
+
+    @Override
+    public void postSolve(Contact contact, ContactImpulse impulse) {
+
+    }
+}
--- a/frontend/core/src/com/game/tankwars/model/Box2dWorld.java
+++ b/frontend/core/src/com/game/tankwars/model/Box2dWorld.java
 package com.game.tankwars.model;

 import com.badlogic.gdx.math.Vector2;
+import com.badlogic.gdx.physics.box2d.Body;
 import com.badlogic.gdx.physics.box2d.World;
+import com.badlogic.gdx.utils.Array;

 public class Box2dWorld {

+    private Array<Body> deadBodies = new Array<>();
+
    private static final World world = new World(new Vector2(0, -10), true);

    public void logicStep(float dt) {
@@ -15,5 +19,18 @@ public class Box2dWorld {
        return world;
    }

+    public void addDeadBody(Body body) {
+        deadBodies.add(body);
+    }
+
+    public void destroyDeadBodies() {
+        if (deadBodies.size > 0) {
+            for (Body b : deadBodies) {
+                world.destroyBody(b);
+            }
+            deadBodies.clear();
+        }
+    }
+

 }
--- a/frontend/core/src/com/game/tankwars/model/Bullet.java
+++ b/frontend/core/src/com/game/tankwars/model/Bullet.java
@@ -24,6 +24,7 @@ public class Bullet {
    private Sprite bulletSprite;

    private float angle;
+    private boolean collision = false;

    public Bullet(Tank tank) {
        this.tank = tank;
@@ -40,6 +41,7 @@ public class Bullet {
        fixtureDef.restitution = 0.0f;
        fixtureDef.friction = 1f;
        body.createFixture(fixtureDef);
+        body.getFixtureList().get(0).setUserData(new FixtureData("bullet"));


        shape.dispose();
@@ -82,6 +84,12 @@ public class Bullet {

    public Body getBody() { return body; }

+    public boolean collision() {
+        return collision;
+    }

+    public void setCollision() {
+        collision = true;
+    }

 }
--- a/frontend/core/src/com/game/tankwars/model/FixtureData.java
+++ b/frontend/core/src/com/game/tankwars/model/FixtureData.java
+package com.game.tankwars.model;
+
+public class FixtureData {
+
+    String id;
+
+    Boolean collision;
+
+    public FixtureData(String id) {
+        this.id = id;
+        this.collision = false;
+    }
+
+    public void hasCollided() {
+        this.collision = true;
+    }
+
+    public boolean isHit() {
+        return collision ? true : false;
+    }
+
+    public String getId() {
+        return id;
+    }
+
+}
--- a/frontend/core/src/com/game/tankwars/model/Tank.java
+++ b/frontend/core/src/com/game/tankwars/model/Tank.java
@@ -45,7 +45,7 @@ public class Tank {
    int fuel = 150;
    int health = 100;

-    public Tank(int posInVertArr, Texture chassisTexture, Texture cannonTexture, Terrain terrain, TankWarsGame tankWarsGame, boolean directionLeft, float cannonAngle) {
+    public Tank(int posInVertArr, Texture chassisTexture, Texture cannonTexture, Terrain terrain, TankWarsGame tankWarsGame, boolean directionLeft, float cannonAngle, String id) {
        VIEWPORT_HEIGHT = tankWarsGame.getViewportHeight();
        VIEWPORT_WIDTH = tankWarsGame.getViewportWidth();

@@ -80,6 +80,7 @@ public class Tank {
        chassis = world.createBody(bodyDef);
        chassis.setUserData(chassisSprite);
        chassis.createFixture(fixtureDef);
+        chassis.getFixtureList().get(0).setUserData(new FixtureData(id));
        chassisSprite.scale(0.2f);

        //Cannon

--- a/frontend/core/src/com/game/tankwars/model/Terrain.java
+++ b/frontend/core/src/com/game/tankwars/model/Terrain.java
@@ -43,6 +43,7 @@ public class Terrain {

        body = world.createBody(bodyDef);
        body.createFixture(fixtureDef);
+        body.getFixtureList().get(0).setUserData(new FixtureData("terrain"));

        chainShape.dispose();
    }

--- a/frontend/core/src/com/game/tankwars/view/GameScreen.java
+++ b/frontend/core/src/com/game/tankwars/view/GameScreen.java
@@ -19,10 +19,12 @@ import com.badlogic.gdx.physics.box2d.Box2DDebugRenderer;
 import com.badlogic.gdx.physics.box2d.World;
 import com.badlogic.gdx.utils.Array;
 import com.badlogic.gdx.utils.viewport.FitViewport;
+import com.game.tankwars.CollisionDetection;
 import com.game.tankwars.TankWarsGame;
 import com.game.tankwars.controller.GameController;
 import com.game.tankwars.model.Box2dWorld;
 import com.game.tankwars.model.Bullet;
+import com.game.tankwars.model.FixtureData;
 import com.game.tankwars.model.Tank;
 import com.game.tankwars.model.Terrain;

@@ -46,8 +48,10 @@ public class GameScreen implements Screen {
    OrthographicCamera hudCam;
    Box2DDebugRenderer debugRenderer;
    GameController controller;
+    CollisionDetection collisionDetection;

    private Bullet bullet;
+    private boolean bulletToDestroy = false;

    public GameScreen(final TankWarsGame tankWarsGame){
        this.tankWarsGame = tankWarsGame;
@@ -61,6 +65,9 @@ public class GameScreen implements Screen {
        model = new Box2dWorld();
        world = Box2dWorld.getWorld();

+        collisionDetection = new CollisionDetection();
+        world.setContactListener(collisionDetection);
+
        worldCam = new OrthographicCamera(scale(TankWarsGame.GAMEPORT_WIDTH), scale(TankWarsGame.GAMEPORT_HEIGHT));
        worldCam.position.set(scale(TankWarsGame.GAMEPORT_WIDTH)/2, scale(TankWarsGame.GAMEPORT_HEIGHT)/2, 0);

@@ -82,14 +89,16 @@ public class GameScreen implements Screen {
                new Texture("camo-tank-barrel.png"),
                terrain,
                tankWarsGame, true,
-                120);
+                120,
+                "userTank");
        opponentTank = new Tank(opponentPos,
                new Texture("camo-tank-1.png"),
                new Texture("camo-tank-barrel.png"),
                terrain,
                tankWarsGame,
                false,
-                225);
+                225,
+                "opponentTank");

        horizontalScaling = Gdx.graphics.getWidth() / TankWarsGame.GAMEPORT_WIDTH;
        verticalScaling = Gdx.graphics.getHeight() / TankWarsGame.GAMEPORT_HEIGHT;
@@ -104,6 +113,7 @@ public class GameScreen implements Screen {
    @Override
    public void render(float delta) {
        model.logicStep(Gdx.graphics.getDeltaTime());
+        model.destroyDeadBodies();
        Gdx.gl.glClearColor(0, 0, 100, 100);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
        debugRenderer.render(world, worldCam.combined);
@@ -146,10 +156,17 @@ public class GameScreen implements Screen {
        terrain.draw(shapeRender);
        shapeRender.end();
        updateBullet();
+        if (checkBulletCollision()) {
+            Body body = this.bullet.getBody();
+            bullet.getBulletSprite().getTexture().dispose();
+            this.bullet = null;
+            model.addDeadBody(body);
+            System.out.println("Destroy body!");
+        }

        batch.begin();
-        if (bullet != (null)) {
-            bullet.getBulletSprite().draw(batch);
+        if (this.bullet != (null)) {
+            this.bullet.getBulletSprite().draw(batch);
        }
        myTank.getChassisSprite().draw(batch);
        myTank.getCannonSprite().draw(batch);
@@ -204,4 +221,17 @@ public class GameScreen implements Screen {
            this.bullet = bullet;
        }
    }
+
+    private boolean checkBulletCollision() {
+        if (this.bullet == null) {
+            return false;
+        }
+        try {
+            FixtureData data = (FixtureData) bullet.getBody().getFixtureList().get(0).getUserData();
+            return data.isHit();
+        } catch (IndexOutOfBoundsException e){
+            return false;
+        }
+
+    }
 }