Set up ECS on GameScreen: register components and systems, add player

core/src/com/me/asteroids/screens/GameScreen.java

@@ -1,10 +1,25 @@
 package com.me.asteroids.screens;
 
+import com.badlogic.gdx.math.Polygon;
+import com.badlogic.gdx.math.Vector2;
+import com.me.asteroids.Constants;
 import com.me.asteroids.Graphics;
+import com.me.asteroids.components.AccelerationComponent;
+import com.me.asteroids.components.ModelComponent;
+import com.me.asteroids.components.PlayerComponent;
+import com.me.asteroids.components.PositionComponent;
+import com.me.asteroids.components.VelocityComponent;
+import com.me.asteroids.systems.ModelRenderSystem;
+import com.me.asteroids.systems.MovementSystem;
+import com.me.asteroids.systems.PlayerInputSystem;
 import com.me.common.Screen;
+import com.me.common.ecs.Engine;
+import com.me.common.ecs.Entity;
 
 public class GameScreen extends Screen {
 
+    Engine engine;
+
     Graphics graphics;
 
     public GameScreen(Graphics graphics) {
@@ -13,12 +28,57 @@ public class GameScreen extends Screen {
 
     @Override
     public void setup() {
+        engine = new Engine();
 
+        engine.registerComponentClass(PlayerComponent.class);
+        engine.registerComponentClass(PositionComponent.class);
+        engine.registerComponentClass(VelocityComponent.class);
+        engine.registerComponentClass(AccelerationComponent.class);
+        engine.registerComponentClass(ModelComponent.class);
+
+        engine.registerSystem(new PlayerInputSystem());
+        engine.registerSystem(new MovementSystem());
+        engine.registerSystem(new ModelRenderSystem(graphics));
+
+        engine.ready();
+
+        Entity player = engine.createEntity();
+
+        PositionComponent position = new PositionComponent();
+        position.position = new Vector2(Constants.HALF_WIDTH, Constants.HALF_HEIGHT);
+        position.rotation = 90;
+        player.addComponent(position);
+
+        VelocityComponent velocity = new VelocityComponent();
+        velocity.velocity = new Vector2(0f, 0f);
+        velocity.maxVelocity = 400f;
+        player.addComponent(velocity);
+
+        ModelComponent shape = new ModelComponent();
+        float[] vertices = new float[] {
+                0f, 4f,         // tip
+                -2.5f, -4f,     // bottom left
+                -1f, -2.5f,     // indent
+                1f, -2.5f,      // indent
+                2.5f, -4f,      // bottom right
+        };
+        shape.model = new Polygon(vertices);
+        shape.model.scale(5);
+        player.addComponent(shape);
+
+        AccelerationComponent accel = new AccelerationComponent();
+        accel.acceleration = new Vector2(0,1f);
+        player.addComponent(accel);
+
+        player.addComponent(new PlayerComponent());
+
+        player.activate();
     }
 
     @Override
     public void update(float dt) {
         graphics.reset();
+        engine.update(dt);
     }
 
     @Override