From 80276c70c45d15c6d972a826db6bea8a7eecee90 Mon Sep 17 00:00:00 2001
From: Glatzemann <glatzemann@users.noreply.github.com>
Date: Mon, 5 Dec 2011 15:55:17 +0000
Subject: [PATCH] some work on OpenGL3 RenderSystem for X11 support (Linux)

---
 .../GraphicsDeviceWindowsGL3.cs               | 92 +++++++++++++++++--
 1 file changed, 85 insertions(+), 7 deletions(-)

diff --git a/RenderSystems/ANX.Framework.Windows.GL3/GraphicsDeviceWindowsGL3.cs b/RenderSystems/ANX.Framework.Windows.GL3/GraphicsDeviceWindowsGL3.cs
index d32a6645..bc502a8a 100644
--- a/RenderSystems/ANX.Framework.Windows.GL3/GraphicsDeviceWindowsGL3.cs
+++ b/RenderSystems/ANX.Framework.Windows.GL3/GraphicsDeviceWindowsGL3.cs
@@ -85,6 +85,41 @@ namespace ANX.Framework.Windows.GL3
             public int Bottom;      // y position of lower-right corner 
         }
 
+        [DllImport("libX11")]
+        static extern IntPtr XCreateColormap(IntPtr display, IntPtr window, IntPtr visual, int alloc);
+
+        [DllImport("libX11", EntryPoint = "XGetVisualInfo")]
+        static extern IntPtr XGetVisualInfoInternal(IntPtr display, IntPtr vinfo_mask, ref XVisualInfo template, out int nitems);
+
+        static IntPtr XGetVisualInfo(IntPtr display, int vinfo_mask, ref XVisualInfo template, out int nitems)
+        {
+            return XGetVisualInfoInternal(display, (IntPtr)vinfo_mask, ref template, out nitems);
+        }
+
+        [DllImport("libX11")]
+        extern static int XPending(IntPtr diplay);
+
+        [StructLayout(LayoutKind.Sequential)]
+        struct XVisualInfo
+        {
+            public IntPtr Visual;
+            public IntPtr VisualID;
+            public int Screen;
+            public int Depth;
+            public int Class;
+            public long RedMask;
+            public long GreenMask;
+            public long blueMask;
+            public int ColormapSize;
+            public int BitsPerRgb;
+
+            public override string ToString()
+            {
+                return String.Format("id ({0}), screen ({1}), depth ({2}), class ({3})",
+                    VisualID, Screen, Depth, Class);
+            }
+        }
+
         #endregion
 
 		#region Private
@@ -179,14 +214,45 @@ namespace ANX.Framework.Windows.GL3
 					break;
 			}
 
-			nativeWindowInfo = Utilities.CreateWindowsWindowInfo(presentationParameters.DeviceWindowHandle);
+            GraphicsMode graphicsMode = new GraphicsMode(DatatypesMapping.SurfaceToColorFormat(presentationParameters.BackBufferFormat),
+                                                         depth, 
+                                                         stencil,
+                                                         presentationParameters.MultiSampleCount // AntiAlias Samples: 2/4/8/16/32
+                                                        );
 
-		GraphicsMode graphicsMode = new GraphicsMode(
-					DatatypesMapping.SurfaceToColorFormat(
-						presentationParameters.BackBufferFormat),
-					depth, stencil,
-				// AntiAlias Samples: 2/4/8/16/32
-					presentationParameters.MultiSampleCount);
+            if (OpenTK.Configuration.RunningOnWindows)
+            {
+                nativeWindowInfo = Utilities.CreateWindowsWindowInfo(presentationParameters.DeviceWindowHandle);
+            }
+            else if (OpenTK.Configuration.RunningOnX11)
+            {
+                // Use reflection to retrieve the necessary values from Mono's Windows.Forms implementation.
+                Type xplatui = Type.GetType("System.Windows.Forms.XplatUIX11, System.Windows.Forms");
+                if (xplatui == null) throw new PlatformNotSupportedException(
+                        "System.Windows.Forms.XplatUIX11 missing. Unsupported platform or Mono runtime version, aborting.");
+
+                // get the required handles from the X11 API.
+                IntPtr display = (IntPtr)GetStaticFieldValue(xplatui, "DisplayHandle");
+                IntPtr rootWindow = (IntPtr)GetStaticFieldValue(xplatui, "RootWindow");
+                int screen = (int)GetStaticFieldValue(xplatui, "ScreenNo");
+
+                // get the XVisualInfo for this GraphicsMode
+                XVisualInfo info = new XVisualInfo();
+                info.VisualID = graphicsMode.Index.Value;
+                int dummy;
+                IntPtr infoPtr = XGetVisualInfo(display, 1 /* VisualInfoMask.ID */, ref info, out dummy);
+                info = (XVisualInfo)Marshal.PtrToStructure(infoPtr, typeof(XVisualInfo));
+
+                // set the X11 colormap.
+                SetStaticFieldValue(xplatui, "CustomVisual", info.Visual);
+                SetStaticFieldValue(xplatui, "CustomColormap", XCreateColormap(display, rootWindow, info.Visual, 0));
+
+                nativeWindowInfo = Utilities.CreateX11WindowInfo(display, screen, presentationParameters.DeviceWindowHandle, rootWindow, infoPtr);
+            }
+            else
+            {
+                throw new NotImplementedException();
+            }
 
             ResizeRenderWindow(presentationParameters);
 
@@ -420,6 +486,18 @@ namespace ANX.Framework.Windows.GL3
             }
         }
 
+        static object GetStaticFieldValue(Type type, string fieldName)
+        {
+            return type.GetField(fieldName,
+                System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic).GetValue(null);
+        }
+
+        static void SetStaticFieldValue(Type type, string fieldName, object value)
+        {
+            type.GetField(fieldName,
+                System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic).SetValue(null, value);
+        }
+
 		public void SetRenderTargets(params RenderTargetBinding[] renderTargets)
 		{
 			throw new NotImplementedException();