# HG changeset patch
# User alys
# Date 2021-04-01 03:06:01
# Node ID 222a32473921bde5a3589d602753b84b99b62b8e
# Parent  ada0c9356941a095b5916556e311e24530ca53de

Add code for drawing outlines of an arbitrary set of squares.

diff --git a/isometric-park-fna/FNAGame.cs b/isometric-park-fna/FNAGame.cs
--- a/isometric-park-fna/FNAGame.cs
+++ b/isometric-park-fna/FNAGame.cs
@@ -739,9 +739,13 @@
         Tile.OutlineSquare(batch, 5, 1, Color.Green, 2);
         Tile.OutlineSquare(batch, 7, 1, Color.Orange, 2);
         Tile.OutlineSquare(batch, 9, 1, Color.Orange, 3);
-        Tile.OutlineSquare2(batch, 12, 1, Color.Orange, 2);
+        // Tile.OutlineSquare2(batch, 12, 1, Color.Orange, 2);
+
+        //Tile.drawEdge(batch, new Edge {Start=new Vector2(14, 1), End= new Vector2(15, 1)}, Color.Orange);
 
-        Tile.drawEdge(batch, new Edge {Start=new Vector2(14, 1), End= new Vector2(15, 1)}, Color.Orange);
+        //donut
+        //Tile.DrawOutlinedSquares(batch, new Vector2[] {new Vector2(19, 1), new Vector2(19, 2), new Vector2(20, 1), new Vector2(21, 1),
+        //        new Vector2(21, 2), new Vector2(19, 3), new Vector2(20, 3), new Vector2(21, 3)}, Color.Purple);
 #endif 
 
 
diff --git a/isometric-park-fna/Tile.cs b/isometric-park-fna/Tile.cs
--- a/isometric-park-fna/Tile.cs
+++ b/isometric-park-fna/Tile.cs
@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
 
 using Microsoft.Xna.Framework;
 using Microsoft.Xna.Framework.Graphics;
@@ -7,8 +9,23 @@
 {
 
     public struct Edge {
-	public Vector2 Start;
-	public Vector2 End;
+		public Vector2 Start;
+		public Vector2 End;
+
+		public static bool operator == (Edge left, Edge right) {
+			return (left.Start == right.Start && left.End == right.End) ||
+				(left.Start == right.End && left.End == right.Start);
+		}
+
+		public static bool operator != (Edge left, Edge right) {
+			return !(left == right);
+		}
+
+		public bool Equals(Object other) {
+			return ((other != null) 
+					&& ! this.GetType().Equals(other.GetType()) 
+					&& this == (Edge)other); //we just confirmed the types match so this is okay
+	}
 
     }
     public class Tile
@@ -150,6 +167,25 @@
 		}
 	}
 
+	public static void DrawOutlinedSquares(SpriteBatch batch, Vector2[] squares, Color color) {
+		List<Edge> edges = new List<Edge>();
+
+		foreach (Vector2 square in squares) {
+			//upper right
+			edges.Add(new Edge {Start=square, End=square + new Vector2(1, 0)});
+			//lower right
+			edges.Add(new Edge {Start=square + new Vector2(1, 0), End=square + new Vector2(1, 1)});
+			//lower left
+			edges.Add(new Edge {Start=square + new Vector2(0, 1), End=square + new Vector2(1, 1)});
+			//upper left
+			edges.Add(new Edge {Start=square, End=square + new Vector2(0, 1)});
+		}
+
+		edges = edges.GroupBy(x => x).Where(grp => grp.Count() == 1).Select(grp => grp.Key).ToList<Edge>();
+
+		drawEdges(batch, edges.ToArray(), color);
+	}
+
 
 	public static void drawTileAt(SpriteBatch batch, int x, int y, int tileIndex, int height, float depth)
 	{