Add screen wrapping system

Move model position/rotation updating to movement system

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

@@ -12,6 +12,7 @@ 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.asteroids.systems.ScreenWrapSystem;
 import com.me.common.Screen;
 import com.me.common.ecs.Engine;
 import com.me.common.ecs.Entity;
@@ -38,6 +39,7 @@ public class GameScreen extends Screen {
 
         engine.registerSystem(new PlayerInputSystem());
         engine.registerSystem(new MovementSystem());
+        engine.registerSystem(new ScreenWrapSystem());
         engine.registerSystem(new ModelRenderSystem(graphics));
 
         engine.ready();

core/src/com/me/asteroids/systems/ModelRenderSystem.java

@@ -3,10 +3,8 @@ package com.me.asteroids.systems;
 import com.badlogic.gdx.graphics.Color;
 import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
 import com.badlogic.gdx.math.Polygon;
-import com.badlogic.gdx.math.Vector2;
 import com.me.asteroids.Graphics;
 import com.me.asteroids.components.ModelComponent;
-import com.me.asteroids.components.PositionComponent;
 import com.me.common.ecs.Entity;
 import com.me.common.ecs.EntitySystem;
 
@@ -15,7 +13,7 @@ public class ModelRenderSystem extends EntitySystem {
     private ShapeRenderer renderer;
 
     public ModelRenderSystem(Graphics graphics) {
-        super(ModelComponent.class, PositionComponent.class);
+        super(ModelComponent.class);
         this.renderer = graphics.getShapeRenderer();
     }
 
@@ -28,15 +26,8 @@ public class ModelRenderSystem extends EntitySystem {
     @Override
     public void processEntity(Entity entity, float dt) {
         ModelComponent modelComponent = entity.getComponent(ModelComponent.class);
-        PositionComponent positionComponent = entity.getComponent(PositionComponent.class);
 
         Polygon model = modelComponent.model;
-        Vector2 position = positionComponent.position;
-        float rotation = positionComponent.rotation;
-
-        model.setPosition(position.x, position.y);
-        model.setRotation(rotation - 90);
-
         renderer.polygon(model.getTransformedVertices());
     }
 

core/src/com/me/asteroids/systems/MovementSystem.java

@@ -1,7 +1,9 @@
 package com.me.asteroids.systems;
 
+import com.badlogic.gdx.math.Polygon;
 import com.badlogic.gdx.math.Vector2;
 import com.me.asteroids.components.AccelerationComponent;
+import com.me.asteroids.components.ModelComponent;
 import com.me.asteroids.components.PositionComponent;
 import com.me.asteroids.components.VelocityComponent;
 import com.me.common.ecs.Entity;
@@ -33,6 +35,13 @@ public class MovementSystem extends EntitySystem {
             velocity.clamp(0, maxVelocity);
             position.add(tmp.set(velocity).scl(dt));
         }
+
+        ModelComponent modelComponent = entity.getComponent(ModelComponent.class);
+        if (modelComponent != null) {
+            Polygon model = modelComponent.model;
+            model.setPosition(position.x, position.y);
+            model.setRotation(positionComponent.rotation - 90);
+        }
     }
 
 }

core/src/com/me/asteroids/systems/ScreenWrapSystem.java

@@ -0,0 +1,49 @@
+package com.me.asteroids.systems;
+
+import com.badlogic.gdx.math.Polygon;
+import com.badlogic.gdx.math.Rectangle;
+import com.badlogic.gdx.math.Vector2;
+import com.me.asteroids.Constants;
+import com.me.asteroids.components.ModelComponent;
+import com.me.asteroids.components.PositionComponent;
+import com.me.common.ecs.Entity;
+import com.me.common.ecs.EntitySystem;
+
+public class ScreenWrapSystem extends EntitySystem {
+
+    public ScreenWrapSystem() {
+        super(PositionComponent.class, ModelComponent.class);
+    }
+
+    @Override
+    public void processEntity(Entity entity, float dt) {
+        PositionComponent positionComponent = entity.getComponent(PositionComponent.class);
+        ModelComponent modelComponent = entity.getComponent(ModelComponent.class);
+
+        Vector2 position = positionComponent.position;
+        Polygon model = modelComponent.model;
+        Rectangle aabb = model.getBoundingRectangle();
+
+        // Check top/bottom edges
+        float minY = aabb.y;
+        float maxY = minY + aabb.height;
+        if (minY > Constants.HEIGHT) {
+            position.y = position.y - maxY;
+            return;
+        } else if (maxY < 0) {
+            position.y = Constants.HEIGHT + (position.y - minY);
+            return;
+        }
+
+        // Check right/left edges
+        float minX = aabb.x;
+        float maxX = minX + aabb.width;
+        if (maxX < 0) {
+            position.x = Constants.WIDTH + (position.x - minX);
+        }  else if (minX > Constants.WIDTH) {
+            position.x = position.x - maxX;
+
+        }
+    }
+
+}