Add parallax scrolling to level

Assets/ParallaxBackground.cs

@@ -4,24 +4,37 @@ using UnityEngine;
 
 public class ParallaxBackground : MonoBehaviour
 {
-    public Camera camera;
-    public SpriteRenderer renderer;
+    [SerializeField] Camera baseCamera;
+    [SerializeField] SpriteRenderer baseRenderer;
     public Vector2 scrollRate = Vector2.one * .4f;
 
+    Vector2 tileSize;
+    Vector2 offset = new Vector2(8f, 7.5f);
+
     // Start is called before the first frame update
     void Start()
     {
-        
+        baseRenderer.transform.position = new Vector3(
+            baseCamera.transform.position.x - offset.x,
+            baseCamera.transform.position.y - offset.y, 
+            baseRenderer.transform.position.z);
+
+        tileSize = baseRenderer.size;
+
+        baseRenderer.size = new Vector2(
+            (Mathf.Ceil(tileSize.x / (offset.x * 2f)) + 2f) * tileSize.x,
+            (Mathf.Ceil(tileSize.y / (offset.y * 2f)) + 2f) * tileSize.y);
     }
 
     // Update is called once per frame
     void Update()
     {
-        //var currentPos = 
-
-        //var offset = new Vector3(8f, -7.5f, 0f);
-
-        //renderer.transform.position = camera.transform.position + ((camera.transform.position * new Vector3(scrollRate.x, scrollRate.y, 0f)) - offset);
+        var depth = baseRenderer.transform.position.z;
+        var basePosition = (Vector2)baseCamera.transform.position - (offset * new Vector2(1f, -1f));
+        var scrollOffset = baseCamera.transform.position * scrollRate;
+        scrollOffset = new Vector2(scrollOffset.x % tileSize.x, scrollOffset.y % tileSize.y);
 
+        var position = basePosition - scrollOffset - tileSize * new Vector2(1, -1);
+        baseRenderer.transform.position = new Vector3(position.x, position.y, depth);
     }
 }