From 4ed6792996762a125f3ae2f0f996c52fd0ca73fb Mon Sep 17 00:00:00 2001
From: Collin Smith <collinsmith70@gmail.com>
Date: Sun, 10 Nov 2019 01:56:23 -0800
Subject: [PATCH] Added physics system placeholder which manages velocity
 application on position

---
 .../riiablo/engine/system/PhysicsSystem.java  | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 core/src/com/riiablo/engine/system/PhysicsSystem.java

diff --git a/core/src/com/riiablo/engine/system/PhysicsSystem.java b/core/src/com/riiablo/engine/system/PhysicsSystem.java
new file mode 100644
index 00000000..ad4f71c3
--- /dev/null
+++ b/core/src/com/riiablo/engine/system/PhysicsSystem.java
@@ -0,0 +1,28 @@
+package com.riiablo.engine.system;
+
+import com.badlogic.ashley.core.ComponentMapper;
+import com.badlogic.ashley.core.Entity;
+import com.badlogic.ashley.core.Family;
+import com.badlogic.ashley.systems.IteratingSystem;
+import com.badlogic.gdx.math.Vector2;
+import com.riiablo.engine.component.PositionComponent;
+import com.riiablo.engine.component.VelocityComponent;
+
+public class PhysicsSystem extends IteratingSystem {
+  private final ComponentMapper<PositionComponent> positionComponent = ComponentMapper.getFor(PositionComponent.class);
+  private final ComponentMapper<VelocityComponent> velocityComponent = ComponentMapper.getFor(VelocityComponent.class);
+
+  public PhysicsSystem() {
+    super(Family.all(PositionComponent.class, VelocityComponent.class).get());
+  }
+
+  @Override
+  protected void processEntity(Entity entity, float delta) {
+    VelocityComponent velocityComponent = this.velocityComponent.get(entity);
+    Vector2 velocity = velocityComponent.velocity;
+    if (velocity.isZero()) return;
+    PositionComponent positionComponent = this.positionComponent.get(entity);
+    Vector2 position = positionComponent.position;
+    position.mulAdd(velocity, delta);
+  }
+}