From b469a3be00941a383964689441cf22dbe62d8d3a Mon Sep 17 00:00:00 2001
From: zeromus <zeromus@zeromus.org>
Date: Fri, 7 Feb 2014 23:06:51 +0000
Subject: [PATCH] bizwaregl - add function to read back the contents of a
 texture into a BitmapBuffer

---
 .../IGL_TK.cs                                 | 11 ++++++++
 Bizware/BizHawk.Bizware.BizwareGL/IGL.cs      |  7 ++++--
 .../BizHawk.Bizware.BizwareGL/Texture2d.cs    | 25 ++++++-------------
 Bizware/BizHawk.Bizware.Test/Program.cs       |  6 +++--
 4 files changed, 27 insertions(+), 22 deletions(-)

diff --git a/Bizware/BizHawk.Bizware.BizwareGL.OpenTK/IGL_TK.cs b/Bizware/BizHawk.Bizware.BizwareGL.OpenTK/IGL_TK.cs
index 78363a7506..b769216156 100644
--- a/Bizware/BizHawk.Bizware.BizwareGL.OpenTK/IGL_TK.cs
+++ b/Bizware/BizHawk.Bizware.BizwareGL.OpenTK/IGL_TK.cs
@@ -434,6 +434,17 @@ namespace BizHawk.Bizware.BizwareGL.Drivers.OpenTK
 			return ret;
 		}
 
+		public unsafe BitmapBuffer ResolveTexture2d(Texture2d tex)
+		{
+			//note - this is dangerous since it changes the bound texture. could we save it?
+			BindTexture2d(tex);
+			var bb = new BitmapBuffer(tex.IntWidth, tex.IntHeight);
+			var bmpdata = bb.LockBits();
+			GL.GetTexImage(TextureTarget.Texture2D, 0, PixelFormat.Bgra, PixelType.Byte, bmpdata.Scan0);
+			bb.UnlockBits(bmpdata);
+			return bb;
+		}
+
 		public Texture2d LoadTexture(string path)
 		{
 			using (var fs = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read))
diff --git a/Bizware/BizHawk.Bizware.BizwareGL/IGL.cs b/Bizware/BizHawk.Bizware.BizwareGL/IGL.cs
index b4946be35b..e365748a10 100644
--- a/Bizware/BizHawk.Bizware.BizwareGL/IGL.cs
+++ b/Bizware/BizHawk.Bizware.BizwareGL/IGL.cs
@@ -19,7 +19,6 @@ namespace BizHawk.Bizware.BizwareGL
 	/// </summary>
 	public interface IGL : IDisposable
 	{
-
 		/// <summary>
 		/// Clears the specified buffer parts
 		/// </summary>
@@ -126,6 +125,11 @@ namespace BizHawk.Bizware.BizwareGL
 		/// </summary>
 		void FreeTexture(IntPtr texHandle);
 
+		/// <summary>
+		/// resolves the texture into a new BitmapBuffer
+		/// </summary>
+		BitmapBuffer ResolveTexture2d(Texture2d texture);
+
 		/// <summary>
 		/// frees the provided render target
 		/// </summary>
@@ -134,7 +138,6 @@ namespace BizHawk.Bizware.BizwareGL
 		/// <summary>
 		/// Binds this texture as the current texture2d target for parameter-specification
 		/// </summary>
-		/// <param name="texture"></param>
 		void BindTexture2d(Texture2d texture);
 
 		/// <summary>
diff --git a/Bizware/BizHawk.Bizware.BizwareGL/Texture2d.cs b/Bizware/BizHawk.Bizware.BizwareGL/Texture2d.cs
index baae303336..b4cbb6093a 100644
--- a/Bizware/BizHawk.Bizware.BizwareGL/Texture2d.cs
+++ b/Bizware/BizHawk.Bizware.BizwareGL/Texture2d.cs
@@ -13,24 +13,13 @@ namespace BizHawk.Bizware.BizwareGL
 	/// </summary>
 	public class Texture2d : IDisposable
 	{
-		//not sure if I need this idea.
-		//public class Maker
-		//{
-		//  public Maker(Texture2d tex)
-		//  {
-		//    MyTexture = tex;
-		//  }
-		//  public void SetWidth(int width)
-		//  {
-		//    MyTexture.Width = width;
-		//  }
-		//  public void SetHeight(int width)
-		//  {
-		//    MyTexture.Height = height;
-		//  }
-
-		//  Texture2d MyTexture;
-		//}
+		/// <summary>
+		/// resolves the texture into a new BitmapBuffer
+		/// </summary>
+		public BitmapBuffer Resolve()
+		{
+			return Owner.ResolveTexture2d(this);
+		}
 
 		public void Dispose()
 		{
diff --git a/Bizware/BizHawk.Bizware.Test/Program.cs b/Bizware/BizHawk.Bizware.Test/Program.cs
index 4e62cb4718..6e58e58dd5 100644
--- a/Bizware/BizHawk.Bizware.Test/Program.cs
+++ b/Bizware/BizHawk.Bizware.Test/Program.cs
@@ -59,6 +59,8 @@ namespace BizHawk.Bizware.Test
 			gr.End();
 			rt.Unbind();
 
+			Texture2d rttex2d = igl.LoadTexture(rt.Texture2d.Resolve());
+
 			//test retroarch shader
 			RenderTarget rt2 = igl.CreateRenderTarget(240, 240);
 			rt2.Bind();
@@ -68,7 +70,7 @@ namespace BizHawk.Bizware.Test
 			using (var stream = typeof(Program).Assembly.GetManifestResourceStream("BizHawk.Bizware.Test.TestImages.4xSoft.glsl"))
 				shader = new RetroShader(igl, new System.IO.StreamReader(stream).ReadToEnd());
 			igl.SetBlendState(igl.BlendNone);
-			shader.Run(rt.Texture2d, new Size(60, 60), new Size(240, 240), true);
+			shader.Run(rttex2d, new Size(60, 60), new Size(240, 240), true);
 
 
 			bool running = true;
@@ -101,7 +103,7 @@ namespace BizHawk.Bizware.Test
 					gr.RectFill(250, 0, 16, 16);
 
 					gr.SetBlendState(igl.BlendNone);
-					gr.Draw(rt.Texture2d, 0, 20);
+					gr.Draw(rttex2d, 0, 20);
 					gr.SetBlendState(igl.BlendNormal);
 
 					sr.RenderString(gr, 0, 0, "?? fps");