From 6bc89ac9d13c396dd10e06015247eae9c144fe01 Mon Sep 17 00:00:00 2001
From: Matt Thorson <mattmakesgames@gmail.com>
Date: Sun, 17 May 2020 17:34:47 -0700
Subject: [PATCH] Grid improvements

---
 src/Core/Scene.bf   |  1 +
 src/Physics/Grid.bf | 58 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)

diff --git a/src/Core/Scene.bf b/src/Core/Scene.bf
index 2d96a61..fd35852 100644
--- a/src/Core/Scene.bf
+++ b/src/Core/Scene.bf
@@ -7,6 +7,7 @@ namespace Strawberry
 	{
 		public float TimeStarted { get; private set; }
 		public Grid SolidGrid;
+		public Rect Bounds;
 
 		private List<Entity> entities;
 		private HashSet<Entity> toRemove;
diff --git a/src/Physics/Grid.bf b/src/Physics/Grid.bf
index 92572e2..0a0b7c4 100644
--- a/src/Physics/Grid.bf
+++ b/src/Physics/Grid.bf
@@ -1,4 +1,5 @@
 using System;
+using Strawberry;
 
 namespace Strawberry
 {
@@ -70,6 +71,63 @@ namespace Strawberry
 		public int CellsX => contents.GetLength(0);
 		public int CellsY => contents.GetLength(1);
 
+		//Expand Edges
+
+		public enum ExpandDirections { Left, Right, Up, Down };
+
+		public void ExpandEdge(ExpandDirections direction, int add = 1)
+		{
+			Runtime.Assert(add > 0);
+
+			char8[,] newContents;
+			if (direction == .Left || direction == .Right)
+				newContents = new char8[CellsX + add, CellsY];
+			else
+				newContents = new char8[CellsX, CellsY + add];
+
+			switch (direction)
+			{
+			case .Left:
+				Offset.X -= CellSize.X * add;
+				for (let x < CellsX)
+					for (let y < CellsY)
+						newContents[x + add, y] = contents[x, y];
+				for (let x < add)
+					for (let y < CellsY)
+						newContents[x, y] = contents[0, y];
+
+			case .Right:
+				for (let x < CellsX)
+					for (let y < CellsY)
+						newContents[x, y] = contents[x, y];
+				for (let x < add)
+					for (let y < CellsY)
+						newContents[CellsX + x, y] = contents[CellsX - 1, y];
+
+			case .Up:
+				Offset.Y -= CellSize.Y * add;
+				for (let x < CellsX)
+					for (let y < CellsY)
+						newContents[x, y + add] = contents[x, y];
+				for (let x < CellsX)
+					for (let y < add)
+						newContents[x, y] = contents[x, 0];
+
+			case .Down:
+				for (let x < CellsX)
+					for (let y < CellsY)
+						newContents[x, y] = contents[x, y];
+				for (let x < CellsX)
+					for (let y < add)
+						newContents[x, CellsY + y] = contents[x, CellsY - 1];
+			}
+
+			delete contents;
+			contents = newContents;
+		}
+
+		//Collision Checks
+
 		public bool IsInBounds(Point p)
 		{
 			return p.X >= 0 && p.Y >= 0 && p.X < CellsX && p.Y < CellsY;