From bfdc36a3e2aa3f4b471bbc5623a75091daa2f926 Mon Sep 17 00:00:00 2001
From: Harrison Deng <yunyangdeng@gmail.com>
Date: Sat, 12 Jan 2019 00:47:17 -0600
Subject: [PATCH] Made a rectangle renderer.

---
 RecrownedAthenaeum/RecrownedAthenaeum.csproj  |   1 +
 .../Render/RectangleRenderer.cs               | 105 ++++++++++++++++++
 2 files changed, 106 insertions(+)
 create mode 100644 RecrownedAthenaeum/Render/RectangleRenderer.cs

diff --git a/RecrownedAthenaeum/RecrownedAthenaeum.csproj b/RecrownedAthenaeum/RecrownedAthenaeum.csproj
index 04fb4a9..ae8b9c6 100644
--- a/RecrownedAthenaeum/RecrownedAthenaeum.csproj
+++ b/RecrownedAthenaeum/RecrownedAthenaeum.csproj
@@ -68,6 +68,7 @@
     <Compile Include="Pipeline\NinePatchDataReader.cs" />
     <Compile Include="Pipeline\TextureAtlasDataReader.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="Render\RectangleRenderer.cs" />
     <Compile Include="Render\PrimitiveBatch.cs" />
     <Compile Include="ScreenSystem\ITransition.cs" />
     <Compile Include="ScreenSystem\LoadingScreen.cs" />
diff --git a/RecrownedAthenaeum/Render/RectangleRenderer.cs b/RecrownedAthenaeum/Render/RectangleRenderer.cs
new file mode 100644
index 0000000..43f23a8
--- /dev/null
+++ b/RecrownedAthenaeum/Render/RectangleRenderer.cs
@@ -0,0 +1,105 @@
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+using RecrownedAthenaeum.Camera;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace RecrownedAthenaeum.Render
+{
+    public class RectangleBatch : IDisposable
+    {
+        public readonly PrimitiveBatch primitiveBatch;
+        private bool disposed;
+        private bool began;
+        private bool filling;
+
+        public RectangleBatch(PrimitiveBatch primitiveBatch)
+        {
+            this.primitiveBatch = primitiveBatch;
+        }
+
+        public RectangleBatch(GraphicsDevice graphicsDevice, Camera2D camera) : this(new PrimitiveBatch(graphicsDevice, camera, 4))
+        {
+
+        }
+
+        public void Begin(bool filled)
+        {
+            filling = filled;
+            if (disposed) throw new ObjectDisposedException(typeof(PrimitiveBatch).Name);
+            if (began) throw new InvalidOperationException("Cannot begin twice.");
+            primitiveBatch.Begin(filled ? PrimitiveType.TriangleStrip : PrimitiveType.LineStrip);
+            began = true;
+        }
+
+        public void End()
+        {
+            if (disposed) throw new ObjectDisposedException(typeof(PrimitiveBatch).Name);
+            if (!began) throw new InvalidOperationException("Cannot end before beginning.");
+            primitiveBatch.End();
+            began = false;
+        }
+
+
+        /// <summary>
+        /// Draws a basic rectangle given bottom left and top right.
+        /// </summary>
+        /// <param name="x">X coordinate of bottom left.</param>
+        /// <param name="y">Y coordinate of bottom left.</param>
+        /// <param name="width">Width of rectangle.</param>
+        /// <param name="height">Height of rectangle.</param>
+        /// <param name="color">Color of all vertices of this rectangle.</param>
+        /// <param name="rotation">Rotation of rectangle. Default is 0 radians.</param>
+        public void Rectangle(int x, int y, int width, int height, Color color, double rotation = 0)
+        {
+            if (disposed) throw new ObjectDisposedException(typeof(PrimitiveBatch).Name);
+            if (!began) throw new InvalidOperationException("Renderer must be started by calling Begin.");
+            Vector2[] corners = new Vector2[4];
+
+            corners[0] = new Vector2(x, y);
+            corners[1] = new Vector2(x + (float)Math.Cos(rotation) * width, y + (float)Math.Sin(rotation) * width);
+            double topRightAngleFromOrig = Math.Atan(height / (double)width);
+            float origDiagonalHypotenuse = (float)Math.Sqrt(width * width * height * height);
+            corners[2] = new Vector2(x + (float)Math.Cos(topRightAngleFromOrig + rotation) * origDiagonalHypotenuse, y + (float)Math.Sin(topRightAngleFromOrig + rotation) * origDiagonalHypotenuse);
+            corners[3] = new Vector2(x + (float)Math.Cos(rotation + Math.PI / 4f) * height, y + (float)Math.Sin(rotation) * height);
+
+            if (filling)
+            {
+                primitiveBatch.AddVertex(corners[1], color);
+                primitiveBatch.AddVertex(corners[2], color);
+                primitiveBatch.AddVertex(corners[0], color);
+                primitiveBatch.AddVertex(corners[3], color);
+            } else
+            {
+                primitiveBatch.AddVertex(corners[0], color);
+                primitiveBatch.AddVertex(corners[1], color);
+                primitiveBatch.AddVertex(corners[2], color);
+                primitiveBatch.AddVertex(corners[3], color);
+            }
+        }
+
+        public void Dispose()
+        {
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        public void Dispose(bool disposing)
+        {
+            if (!disposed && disposing)
+            {
+                if (primitiveBatch != null)
+                {
+                    primitiveBatch.Dispose();
+                }
+            }
+            else
+            {
+                if (disposed) throw new ObjectDisposedException(typeof(PrimitiveBatch).Name);
+            }
+        }
+    }
+}