From df6cee8df1951991f00f93dde4c8a34255bbed66 Mon Sep 17 00:00:00 2001
From: Colin McMillen <colin@semicolin.games>
Date: Mon, 9 Dec 2019 17:21:22 -0500
Subject: [PATCH] partial work toward keeping multiple render targets around
 for GIF encoding

GitOrigin-RevId: 8061896562453a95013ada91df852afc9e904c76
---
 Jumpy.Shared/JumpyGame.cs | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/Jumpy.Shared/JumpyGame.cs b/Jumpy.Shared/JumpyGame.cs
index a9be9c4..8fb0958 100644
--- a/Jumpy.Shared/JumpyGame.cs
+++ b/Jumpy.Shared/JumpyGame.cs
@@ -2,13 +2,16 @@
 using Microsoft.Xna.Framework.Graphics;
 using Microsoft.Xna.Framework.Input;
 
-using System;
 using System.Collections.Generic;
 
 namespace Jumpy {
   public class JumpyGame : Game {
     GraphicsDeviceManager graphics;
-    RenderTarget2D renderTarget;
+
+    const int numRenderTargets = 1;
+    RenderTarget2D[] renderTargets = new RenderTarget2D[numRenderTargets];
+    int renderTargetIdx = 0;
+
     SpriteBatch spriteBatch;
     SpriteFont font;
     KeyboardInput keyboardInput = new KeyboardInput();
@@ -29,10 +32,12 @@ namespace Jumpy {
       display = (IDisplay) Services.GetService(typeof(IDisplay));
       display.Initialize(Window, graphics);
       display.SetFullScreen(fullScreen);
-
-      renderTarget = new RenderTarget2D(
-        GraphicsDevice, Camera.Width, Camera.Height, false /* mipmap */,
-        GraphicsDevice.PresentationParameters.BackBufferFormat, DepthFormat.Depth24);
+            
+      for (int i = 0; i < renderTargets.Length; i++) {
+        renderTargets[i] = new RenderTarget2D(
+          GraphicsDevice, Camera.Width, Camera.Height, false /* mipmap */,
+          GraphicsDevice.PresentationParameters.BackBufferFormat, DepthFormat.Depth24);
+      }
 
       base.Initialize();
     }
@@ -77,8 +82,9 @@ namespace Jumpy {
       fpsCounter.Update();
 
       // Draw scene to RenderTarget.
+      RenderTarget2D renderTarget = renderTargets[renderTargetIdx];
+      renderTargetIdx = (renderTargetIdx + 1) % renderTargets.Length;
       GraphicsDevice.SetRenderTarget(renderTarget);
-      // GraphicsDevice.DepthStencilState = new DepthStencilState() { DepthBufferEnable = true };
       GraphicsDevice.Clear(Color.CornflowerBlue);
       spriteBatch.Begin();
       player.Draw(gameTime, spriteBatch);