Replace MiniTK.Graphics with custom OpenGL shim.

2015-12-26 13:49:28 +00:00
parent 4660b7156d
commit 397ca0f481
8 changed files with 614 additions and 171 deletions
--- a/OpenRA.Platforms.Default/ErrorHandler.cs
+++ b/OpenRA.Platforms.Default/ErrorHandler.cs
@@ -10,7 +10,6 @@

 using System;
 using System.Diagnostics;
-using OpenTK.Graphics.OpenGL;

 namespace OpenRA.Platforms.Default
 {
@@ -18,7 +17,7 @@ namespace OpenRA.Platforms.Default
 	{
 		public static void CheckGlVersion()
 		{
-			var versionString = GL.GetString(StringName.Version);
+			var versionString = OpenGL.glGetString(OpenGL.GL_VERSION);
 			var version = versionString.Contains(" ") ? versionString.Split(' ')[0].Split('.') : versionString.Split('.');

 			var major = 0;
@@ -39,8 +38,8 @@ namespace OpenRA.Platforms.Default

 		public static void CheckGlError()
 		{
-			var n = GL.GetError();
-			if (n != ErrorCode.NoError)
+			var n = OpenGL.glGetError();
+			if (n != OpenGL.GL_NO_ERROR)
 			{
 				var error = "GL Error: {0}\n{1}".F(n, new StackTrace());
 				WriteGraphicsLog(error);
@@ -53,8 +52,9 @@ namespace OpenRA.Platforms.Default
 			Log.Write("graphics", message);
 			Log.Write("graphics", "");
 			Log.Write("graphics", "OpenGL Information:");
-			Log.Write("graphics", "Vendor: {0}", GL.GetString(StringName.Vendor));
-			if (GL.GetString(StringName.Vendor).Contains("Microsoft"))
+			var vendor = OpenGL.glGetString(OpenGL.GL_VENDOR);
+			Log.Write("graphics", "Vendor: {0}", vendor);
+			if (vendor.Contains("Microsoft"))
 			{
 				var msg = "";
 				msg += "Note:  The default driver provided by Microsoft does not include full OpenGL support.\n";
@@ -62,11 +62,11 @@ namespace OpenRA.Platforms.Default
 				Log.Write("graphics", msg);
 			}

-			Log.Write("graphics", "Renderer: {0}", GL.GetString(StringName.Renderer));
-			Log.Write("graphics", "GL Version: {0}", GL.GetString(StringName.Version));
-			Log.Write("graphics", "Shader Version: {0}", GL.GetString(StringName.ShadingLanguageVersion));
+			Log.Write("graphics", "Renderer: {0}", OpenGL.glGetString(OpenGL.GL_RENDERER));
+			Log.Write("graphics", "GL Version: {0}", OpenGL.glGetString(OpenGL.GL_VERSION));
+			Log.Write("graphics", "Shader Version: {0}", OpenGL.glGetString(OpenGL.GL_SHADING_LANGUAGE_VERSION));
 			Log.Write("graphics", "Available extensions:");
-			Log.Write("graphics", GL.GetString(StringName.Extensions));
+			Log.Write("graphics", OpenGL.glGetString(OpenGL.GL_EXTENSIONS));
 		}
 	}
 }
--- a/OpenRA.Platforms.Default/FrameBuffer.cs
+++ b/OpenRA.Platforms.Default/FrameBuffer.cs
@@ -12,7 +12,6 @@ using System;
 using System.Diagnostics;
 using System.Drawing;
 using System.IO;
-using OpenTK.Graphics.OpenGL;

 namespace OpenRA.Platforms.Default
 {
@@ -20,7 +19,7 @@ namespace OpenRA.Platforms.Default
 	{
 		readonly Texture texture;
 		readonly Size size;
-		int framebuffer, depth;
+		uint framebuffer, depth;
 		bool disposed;

 		public FrameBuffer(Size size)
@@ -29,33 +28,33 @@ namespace OpenRA.Platforms.Default
 			if (!Exts.IsPowerOf2(size.Width) || !Exts.IsPowerOf2(size.Height))
 				throw new InvalidDataException("Frame buffer size ({0}x{1}) must be a power of two".F(size.Width, size.Height));

-			GL.Ext.GenFramebuffers(1, out framebuffer);
+			OpenGL.glGenFramebuffersEXT(1, out framebuffer);
 			ErrorHandler.CheckGlError();
-			GL.Ext.BindFramebuffer(FramebufferTarget.FramebufferExt, framebuffer);
+			OpenGL.glBindFramebufferEXT(OpenGL.FRAMEBUFFER_EXT, framebuffer);
 			ErrorHandler.CheckGlError();

 			// Color
 			texture = new Texture();
 			texture.SetEmpty(size.Width, size.Height);
-			GL.Ext.FramebufferTexture2D(FramebufferTarget.FramebufferExt, FramebufferAttachment.ColorAttachment0Ext, TextureTarget.Texture2D, texture.ID, 0);
+			OpenGL.glFramebufferTexture2DEXT(OpenGL.FRAMEBUFFER_EXT, OpenGL.COLOR_ATTACHMENT0_EXT, OpenGL.GL_TEXTURE_2D, texture.ID, 0);
 			ErrorHandler.CheckGlError();

 			// Depth
-			GL.Ext.GenRenderbuffers(1, out depth);
+			OpenGL.glGenRenderbuffersEXT(1, out depth);
 			ErrorHandler.CheckGlError();

-			GL.Ext.BindRenderbuffer(RenderbufferTarget.RenderbufferExt, depth);
+			OpenGL.glBindRenderbufferEXT(OpenGL.RENDERBUFFER_EXT, depth);
 			ErrorHandler.CheckGlError();

-			GL.Ext.RenderbufferStorage(RenderbufferTarget.RenderbufferExt, RenderbufferStorage.DepthComponent, size.Width, size.Height);
+			OpenGL.glRenderbufferStorageEXT(OpenGL.RENDERBUFFER_EXT, OpenGL.GL_DEPTH_COMPONENT, size.Width, size.Height);
 			ErrorHandler.CheckGlError();

-			GL.Ext.FramebufferRenderbuffer(FramebufferTarget.FramebufferExt, FramebufferAttachment.DepthAttachmentExt, RenderbufferTarget.RenderbufferExt, depth);
+			OpenGL.glFramebufferRenderbufferEXT(OpenGL.FRAMEBUFFER_EXT, OpenGL.DEPTH_ATTACHMENT_EXT, OpenGL.RENDERBUFFER_EXT, depth);
 			ErrorHandler.CheckGlError();

 			// Test for completeness
-			var status = GL.Ext.CheckFramebufferStatus(FramebufferTarget.FramebufferExt);
-			if (status != FramebufferErrorCode.FramebufferCompleteExt)
+			var status = OpenGL.glCheckFramebufferStatus(OpenGL.FRAMEBUFFER_EXT);
+			if (status != OpenGL.FRAMEBUFFER_COMPLETE_EXT)
 			{
 				var error = "Error creating framebuffer: {0}\n{1}".F(status, new StackTrace());
 				ErrorHandler.WriteGraphicsLog(error);
@@ -63,7 +62,7 @@ namespace OpenRA.Platforms.Default
 			}

 			// Restore default buffer
-			GL.Ext.BindFramebuffer(FramebufferTarget.FramebufferExt, 0);
+			OpenGL.glBindFramebufferEXT(OpenGL.FRAMEBUFFER_EXT, 0);
 			ErrorHandler.CheckGlError();
 		}

@@ -73,7 +72,7 @@ namespace OpenRA.Platforms.Default
 			unsafe
 			{
 				fixed (int* ptr = &v[0])
-					GL.GetInteger(GetPName.Viewport, ptr);
+					OpenGL.glGetIntegerv(OpenGL.GL_VIEWPORT, ptr);
 			}

 			ErrorHandler.CheckGlError();
@@ -88,26 +87,26 @@ namespace OpenRA.Platforms.Default
 			// Cache viewport rect to restore when unbinding
 			cv = ViewportRectangle();

-			GL.Flush();
+			OpenGL.glFlush();
 			ErrorHandler.CheckGlError();
-			GL.Ext.BindFramebuffer(FramebufferTarget.FramebufferExt, framebuffer);
+			OpenGL.glBindFramebufferEXT(OpenGL.FRAMEBUFFER_EXT, framebuffer);
 			ErrorHandler.CheckGlError();
-			GL.Viewport(0, 0, size.Width, size.Height);
+			OpenGL.glViewport(0, 0, size.Width, size.Height);
 			ErrorHandler.CheckGlError();
-			GL.ClearColor(0, 0, 0, 0);
+			OpenGL.glClearColor(0, 0, 0, 0);
 			ErrorHandler.CheckGlError();
-			GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
+			OpenGL.glClear(OpenGL.GL_COLOR_BUFFER_BIT | OpenGL.GL_DEPTH_BUFFER_BIT);
 			ErrorHandler.CheckGlError();
 		}

 		public void Unbind()
 		{
 			VerifyThreadAffinity();
-			GL.Flush();
+			OpenGL.glFlush();
 			ErrorHandler.CheckGlError();
-			GL.Ext.BindFramebuffer(FramebufferTarget.FramebufferExt, 0);
+			OpenGL.glBindFramebufferEXT(OpenGL.FRAMEBUFFER_EXT, 0);
 			ErrorHandler.CheckGlError();
-			GL.Viewport(cv[0], cv[1], cv[2], cv[3]);
+			OpenGL.glViewport(cv[0], cv[1], cv[2], cv[3]);
 			ErrorHandler.CheckGlError();
 		}

@@ -138,9 +137,10 @@ namespace OpenRA.Platforms.Default
 			disposed = true;
 			if (disposing)
 				texture.Dispose();
-			GL.Ext.DeleteFramebuffers(1, ref framebuffer);
+
+			OpenGL.glDeleteFramebuffersEXT(1, ref framebuffer);
 			ErrorHandler.CheckGlError();
-			GL.Ext.DeleteRenderbuffers(1, ref depth);
+			OpenGL.glDeleteRenderbuffersEXT(1, ref depth);
 			ErrorHandler.CheckGlError();
 		}
 	}
--- a/OpenRA.Platforms.Default/OpenGL.cs
+++ b/OpenRA.Platforms.Default/OpenGL.cs
@@ -0,0 +1,413 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2015 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation. For more information,
+ * see COPYING.
+ */
+#endregion
+
+using System;
+using System.Diagnostics.CodeAnalysis;
+using System.Runtime.InteropServices;
+using System.Text;
+using SDL2;
+
+namespace OpenRA.Platforms.Default
+{
+	[SuppressMessage("Microsoft.StyleCop.CSharp.NamingRules", "SA1300:ElementMustBeginWithUpperCaseLetter",
+		Justification = "C-style naming is kept for consistency with the underlying native API.")]
+	[SuppressMessage("Microsoft.StyleCop.CSharp.NamingRules", "SA1310:FieldNamesMustNotContainUnderscore",
+		Justification = "C-style naming is kept for consistency with the underlying native API.")]
+	internal static class OpenGL
+	{
+		public const int GL_FALSE = 0;
+
+		// ClearBufferMask
+		public const int GL_COLOR_BUFFER_BIT = 0x4000;
+		public const int GL_DEPTH_BUFFER_BIT = 0x0100;
+		public const int GL_STENCIL_BUFFER_BIT = 0x0400;
+
+		// Data types
+		public const int GL_UNSIGNED_BYTE = 0x1401;
+		public const int GL_FLOAT = 0x1406;
+
+		// Errors
+		public const int GL_NO_ERROR = 0;
+
+		// BeginMode
+		public const int GL_POINTS = 0;
+		public const int GL_LINES = 0x0001;
+		public const int GL_TRIANGLES = 0x0004;
+
+		// EnableCap
+		public const int GL_ALPHA_TEST = 0x0BC0;
+		public const int GL_BLEND = 0x0BE2;
+		public const int GL_STENCIL_TEST = 0x0B90;
+		public const int GL_DEPTH_TEST = 0x0B71;
+		public const int GL_SCISSOR_TEST = 0x0C11;
+
+		// Texture mapping
+		public const int GL_TEXTURE_2D = 0x0DE1;
+		public const int GL_TEXTURE_WRAP_S = 0x2802;
+		public const int GL_TEXTURE_WRAP_T = 0x2803;
+		public const int GL_TEXTURE_MAG_FILTER = 0x2800;
+		public const int GL_TEXTURE_MIN_FILTER = 0x2801;
+		public const int GL_NEAREST = 0x2600;
+		public const int GL_LINEAR = 0x2601;
+
+		// Depth buffer
+		public const int GL_DEPTH_COMPONENT = 0x1902;
+
+		// BlendingFactorDest
+		public const int GL_ZERO = 0;
+		public const int GL_ONE = 1;
+		public const int GL_SRC_COLOR = 0x0300;
+		public const int GL_ONE_MINUS_SRC_COLOR = 0x0301;
+		public const int GL_SRC_ALPHA = 0x0302;
+		public const int GL_ONE_MINUS_SRC_ALPHA = 0x0303;
+		public const int GL_DST_ALPHA = 0x0304;
+		public const int GL_ONE_MINUS_DST_ALPHA = 0x0305;
+		public const int GL_DST_COLOR = 0x0306;
+		public const int GL_ONE_MINUS_DST_COLOR = 0x0307;
+
+		// GL_ARB_imaging
+		public const int GL_FUNC_ADD = 0x8006;
+		public const int GL_FUNC_SUBTRACT = 0x800A;
+		public const int GL_FUNC_REVERSE_SUBTRACT = 0x800B;
+		public const int GL_BLEND_COLOR = 0x8005;
+
+		// OpenGL 1.1 - 1.5
+		public const int GL_CLIENT_PIXEL_STORE_BIT = 0x0001;
+		public const int GL_BGRA = 0x80E1;
+		public const int GL_RGBA8 = 0x8058;
+		public const int GL_CLAMP_TO_EDGE = 0x812F;
+		public const int GL_TEXTURE_BASE_LEVEL = 0x813C;
+		public const int GL_TEXTURE_MAX_LEVEL = 0x813D;
+
+		public const int GL_ARRAY_BUFFER = 0x8892;
+		public const int GL_DYNAMIC_DRAW = 0x88E8;
+
+		public const int GL_TEXTURE0 = 0x84C0;
+
+		// OpenGL 2
+		public const int GL_FRAGMENT_SHADER = 0x8B30;
+		public const int GL_VERTEX_SHADER = 0x8B31;
+		public const int GL_SAMPLER_2D = 0x8B5E;
+		public const int GL_COMPILE_STATUS = 0x8B81;
+		public const int GL_LINK_STATUS = 0x8B82;
+		public const int GL_INFO_LOG_LENGTH = 0x8B84;
+		public const int GL_ACTIVE_UNIFORMS = 0x8B86;
+
+		// Pixel Mode / Transfer
+		public const int GL_PACK_ROW_LENGTH = 0x0D02;
+		public const int GL_PACK_ALIGNMENT = 0x0D05;
+
+		// Gets
+		public const int GL_VIEWPORT = 0x0BA2;
+
+		// Utility
+		public const int GL_VENDOR = 0x1F00;
+		public const int GL_RENDERER = 0x1F01;
+		public const int GL_VERSION = 0x1F02;
+		public const int GL_EXTENSIONS = 0x1F03;
+		public const int GL_SHADING_LANGUAGE_VERSION = 0x8B8C;
+
+		// Framebuffers
+		public const int FRAMEBUFFER_EXT = 0x8D40;
+		public const int RENDERBUFFER_EXT = 0x8D41;
+		public const int COLOR_ATTACHMENT0_EXT = 0x8CE0;
+		public const int DEPTH_ATTACHMENT_EXT = 0x8D00;
+		public const int FRAMEBUFFER_COMPLETE_EXT = 0x8CD5;
+
+		public delegate void Flush();
+		public static Flush glFlush { get; private set; }
+
+		public delegate void Viewport(int x, int y, int width, int height);
+		public static Viewport glViewport { get; private set; }
+
+		public delegate void Clear(int mask);
+		public static Clear glClear { get; private set; }
+
+		public delegate void ClearColor(float red, float green, float blue, float alpha);
+		public static ClearColor glClearColor { get; private set; }
+
+		public delegate int GetError();
+		public static GetError glGetError { get; private set; }
+
+		delegate IntPtr GetString(int name);
+		static GetString glGetStringInternal;
+
+		public static string glGetString(int name)
+		{
+			unsafe
+			{
+				return new string((sbyte*)glGetStringInternal(name));
+			}
+		}
+
+		public unsafe delegate int GetIntegerv(int pname, int* param);
+		public static GetIntegerv glGetIntegerv { get; private set; }
+
+		public delegate void Finish();
+		public static Finish glFinish { get; private set; }
+
+		public delegate uint CreateProgram();
+		public static CreateProgram glCreateProgram { get; private set; }
+
+		public delegate void UseProgram(uint program);
+		public static UseProgram glUseProgram { get; private set; }
+
+		public delegate void GetProgramiv(uint program, int pname, out int param);
+		public static GetProgramiv glGetProgramiv { get; private set; }
+
+		public delegate uint CreateShader(int shaderType);
+		public static CreateShader glCreateShader { get; private set; }
+
+		public delegate void ShaderSource(uint shader, int count, string[] str, IntPtr length);
+		public static ShaderSource glShaderSource { get; private set; }
+
+		public delegate void CompileShader(uint shader);
+		public static CompileShader glCompileShader { get; private set; }
+
+		public delegate int GetShaderiv(uint shader, int name, out int param);
+		public static GetShaderiv glGetShaderiv { get; private set; }
+
+		public delegate void AttachShader(uint program, uint shader);
+		public static AttachShader glAttachShader { get; private set; }
+
+		public delegate void GetShaderInfoLog(uint shader, int maxLength, out int length, StringBuilder infoLog);
+		public static GetShaderInfoLog glGetShaderInfoLog { get; private set; }
+
+		public delegate void LinkProgram(uint program);
+		public static LinkProgram glLinkProgram { get; private set; }
+
+		public delegate void GetProgramInfoLog(uint program, int maxLength, out int length, StringBuilder infoLog);
+		public static GetProgramInfoLog glGetProgramInfoLog { get; private set; }
+
+		public delegate int GetUniformLocation(uint program, string name);
+		public static GetUniformLocation glGetUniformLocation { get; private set; }
+
+		public delegate void GetActiveUniform(uint program, int index, int bufSize,
+			out int length, out int size, out int type, StringBuilder name);
+		public static GetActiveUniform glGetActiveUniform { get; private set; }
+
+		public delegate void Uniform1i(int location, int v0);
+		public static Uniform1i glUniform1i { get; private set; }
+
+		public delegate void Uniform1f(int location, float v0);
+		public static Uniform1f glUniform1f { get; private set; }
+
+		public delegate void Uniform2f(int location, float v0, float v1);
+		public static Uniform2f glUniform2f { get; private set; }
+
+		public delegate void Uniform1fv(int location, int count, IntPtr value);
+		public static Uniform1fv glUniform1fv { get; private set; }
+
+		public delegate void Uniform2fv(int location, int count, IntPtr value);
+		public static Uniform2fv glUniform2fv { get; private set; }
+
+		public delegate void Uniform3fv(int location, int count, IntPtr value);
+		public static Uniform3fv glUniform3fv { get; private set; }
+
+		public delegate void Uniform4fv(int location, int count, IntPtr value);
+		public static Uniform4fv glUniform4fv { get; private set; }
+
+		public delegate void UniformMatrix4fv(int location, int count, bool transpose, IntPtr value);
+		public static UniformMatrix4fv glUniformMatrix4fv { get; private set; }
+
+		public delegate void GenBuffers(int n, out uint buffers);
+		public static GenBuffers glGenBuffers { get; private set; }
+
+		public delegate void BindBuffer(int target, uint buffer);
+		public static BindBuffer glBindBuffer { get; private set; }
+
+		public delegate void BufferData(int target, IntPtr size, IntPtr data, int usage);
+		public static BufferData glBufferData { get; private set; }
+
+		public delegate void BufferSubData(int target, IntPtr offset, IntPtr size, IntPtr data);
+		public static BufferSubData glBufferSubData { get; private set; }
+
+		public delegate void DeleteBuffers(int n, ref uint buffers);
+		public static DeleteBuffers glDeleteBuffers { get; private set; }
+
+		public delegate void BindAttribLocation(uint program, int index, string name);
+		public static BindAttribLocation glBindAttribLocation { get; private set; }
+
+		public delegate void VertexAttribPointer(int index, int size, int type, bool normalized,
+			int stride, IntPtr pointer);
+		public static VertexAttribPointer glVertexAttribPointer { get; private set; }
+
+		public delegate void EnableVertexAttribArray(int index);
+		public static EnableVertexAttribArray glEnableVertexAttribArray { get; private set; }
+
+		public delegate void DisableVertexAttribArray(int index);
+		public static DisableVertexAttribArray glDisableVertexAttribArray { get; private set; }
+
+		public delegate void DrawArrays(int mode, int first, int count);
+		public static DrawArrays glDrawArrays { get; private set; }
+
+		public delegate void Enable(int cap);
+		public static Enable glEnable { get; private set; }
+
+		public delegate void Disable(int cap);
+		public static Disable glDisable { get; private set; }
+
+		public delegate void BlendEquation(int mode);
+		public static BlendEquation glBlendEquation { get; private set; }
+
+		public delegate void BlendFunc(int sfactor, int dfactor);
+		public static BlendFunc glBlendFunc { get; private set; }
+
+		public delegate void Scissor(int x, int y, int width, int height);
+		public static Scissor glScissor { get; private set; }
+
+		public delegate void PushClientAttrib(int mask);
+		public static PushClientAttrib glPushClientAttrib { get; private set; }
+
+		public delegate void PopClientAttrib();
+		public static PopClientAttrib glPopClientAttrib { get; private set; }
+
+		public delegate void PixelStoref(int param, float pname);
+		public static PixelStoref glPixelStoref { get; private set; }
+
+		public delegate void ReadPixels(int x, int y, int width, int height,
+			int format, int type, IntPtr data);
+		public static ReadPixels glReadPixels { get; private set; }
+
+		public delegate void GenTextures(int n, out uint textures);
+		public static GenTextures glGenTextures { get; private set; }
+
+		public delegate void DeleteTextures(int n, ref uint textures);
+		public static DeleteTextures glDeleteTextures { get; private set; }
+
+		public delegate void BindTexture(int target, uint texture);
+		public static BindTexture glBindTexture { get; private set; }
+
+		public delegate void ActiveTexture(int texture);
+		public static ActiveTexture glActiveTexture { get; private set; }
+
+		public delegate void TexImage2D(int target, int level, int internalFormat,
+			int width, int height, int border, int format, int type, IntPtr pixels);
+		public static TexImage2D glTexImage2D { get; private set; }
+
+		public delegate void GetTexImage(int target, int level,
+			int format, int type, IntPtr pixels);
+		public static GetTexImage glGetTexImage { get; private set; }
+
+		public delegate void TexParameteri(int target, int pname, int param);
+		public static TexParameteri glTexParameteri { get; private set; }
+
+		public delegate void TexParameterf(int target, int pname, float param);
+		public static TexParameterf glTexParameterf { get; private set; }
+
+		public delegate void GenFramebuffersEXT(int n, out uint framebuffers);
+		public static GenFramebuffersEXT glGenFramebuffersEXT { get; private set; }
+
+		public delegate void BindFramebufferEXT(int target, uint framebuffer);
+		public static BindFramebufferEXT glBindFramebufferEXT { get; private set; }
+
+		public delegate void FramebufferTexture2DEXT(int target, int attachment,
+			int textarget, uint texture, int level);
+		public static FramebufferTexture2DEXT glFramebufferTexture2DEXT { get; private set; }
+
+		public delegate void DeleteFramebuffersEXT(int n, ref uint framebuffers);
+		public static DeleteFramebuffersEXT glDeleteFramebuffersEXT { get; private set; }
+
+		public delegate void GenRenderbuffersEXT(int n, out uint renderbuffers);
+		public static GenRenderbuffersEXT glGenRenderbuffersEXT { get; private set; }
+
+		public delegate void BindRenderbufferEXT(int target, uint renderbuffer);
+		public static BindRenderbufferEXT glBindRenderbufferEXT { get; private set; }
+
+		public delegate void RenderbufferStorageEXT(int target, int internalformat,
+			int width, int height);
+		public static RenderbufferStorageEXT glRenderbufferStorageEXT { get; private set; }
+
+		public delegate void DeleteRenderbuffersEXT(int n, ref uint renderbuffers);
+		public static DeleteRenderbuffersEXT glDeleteRenderbuffersEXT { get; private set; }
+
+		public delegate void FramebufferRenderbufferEXT(int target, int attachment,
+			int renderbuffertarget, uint renderbuffer);
+		public static FramebufferRenderbufferEXT glFramebufferRenderbufferEXT { get; private set; }
+
+		public delegate int CheckFramebufferStatus(int target);
+		public static CheckFramebufferStatus glCheckFramebufferStatus { get; private set; }
+
+		public static void LoadDelegates()
+		{
+			glFlush = Bind<Flush>("glFlush");
+			glViewport = Bind<Viewport>("glViewport");
+			glClear = Bind<Clear>("glClear");
+			glClearColor = Bind<ClearColor>("glClearColor");
+			glGetError = Bind<GetError>("glGetError");
+			glGetStringInternal = Bind<GetString>("glGetString");
+			glGetIntegerv = Bind<GetIntegerv>("glGetIntegerv");
+			glFinish = Bind<Finish>("glFinish");
+			glCreateProgram = Bind<CreateProgram>("glCreateProgram");
+			glUseProgram = Bind<UseProgram>("glUseProgram");
+			glGetProgramiv = Bind<GetProgramiv>("glGetProgramiv");
+			glCreateShader = Bind<CreateShader>("glCreateShader");
+			glShaderSource = Bind<ShaderSource>("glShaderSource");
+			glCompileShader = Bind<CompileShader>("glCompileShader");
+			glGetShaderiv = Bind<GetShaderiv>("glGetShaderiv");
+			glAttachShader = Bind<AttachShader>("glAttachShader");
+			glGetShaderInfoLog = Bind<GetShaderInfoLog>("glGetShaderInfoLog");
+			glLinkProgram = Bind<LinkProgram>("glLinkProgram");
+			glGetProgramInfoLog = Bind<GetProgramInfoLog>("glGetProgramInfoLog");
+			glGetUniformLocation = Bind<GetUniformLocation>("glGetUniformLocation");
+			glGetActiveUniform = Bind<GetActiveUniform>("glGetActiveUniform");
+			glUniform1i = Bind<Uniform1i>("glUniform1i");
+			glUniform1f = Bind<Uniform1f>("glUniform1f");
+			glUniform2f = Bind<Uniform2f>("glUniform2f");
+			glUniform1fv = Bind<Uniform1fv>("glUniform1fv");
+			glUniform2fv = Bind<Uniform2fv>("glUniform2fv");
+			glUniform3fv = Bind<Uniform3fv>("glUniform3fv");
+			glUniform4fv = Bind<Uniform4fv>("glUniform4fv");
+			glUniformMatrix4fv = Bind<UniformMatrix4fv>("glUniformMatrix4fv");
+			glGenBuffers = Bind<GenBuffers>("glGenBuffers");
+			glBindBuffer = Bind<BindBuffer>("glBindBuffer");
+			glBufferData = Bind<BufferData>("glBufferData");
+			glBufferSubData = Bind<BufferSubData>("glBufferSubData");
+			glDeleteBuffers = Bind<DeleteBuffers>("glDeleteBuffers");
+			glBindAttribLocation = Bind<BindAttribLocation>("glBindAttribLocation");
+			glVertexAttribPointer = Bind<VertexAttribPointer>("glVertexAttribPointer");
+			glEnableVertexAttribArray = Bind<EnableVertexAttribArray>("glEnableVertexAttribArray");
+			glDisableVertexAttribArray = Bind<DisableVertexAttribArray>("glDisableVertexAttribArray");
+			glDrawArrays = Bind<DrawArrays>("glDrawArrays");
+			glEnable = Bind<Enable>("glEnable");
+			glDisable = Bind<Disable>("glDisable");
+			glBlendEquation = Bind<BlendEquation>("glBlendEquation");
+			glBlendFunc = Bind<BlendFunc>("glBlendFunc");
+			glScissor = Bind<Scissor>("glScissor");
+			glPushClientAttrib = Bind<PushClientAttrib>("glPushClientAttrib");
+			glPopClientAttrib = Bind<PopClientAttrib>("glPopClientAttrib");
+			glPixelStoref = Bind<PixelStoref>("glPixelStoref");
+			glReadPixels = Bind<ReadPixels>("glReadPixels");
+			glGenTextures = Bind<GenTextures>("glGenTextures");
+			glDeleteTextures = Bind<DeleteTextures>("glDeleteTextures");
+			glBindTexture = Bind<BindTexture>("glBindTexture");
+			glActiveTexture = Bind<ActiveTexture>("glActiveTexture");
+			glTexImage2D = Bind<TexImage2D>("glTexImage2D");
+			glGetTexImage = Bind<GetTexImage>("glGetTexImage");
+			glTexParameteri = Bind<TexParameteri>("glTexParameteri");
+			glTexParameterf = Bind<TexParameterf>("glTexParameterf");
+			glGenFramebuffersEXT = Bind<GenFramebuffersEXT>("glGenFramebuffersEXT");
+			glBindFramebufferEXT = Bind<BindFramebufferEXT>("glBindFramebufferEXT");
+			glFramebufferTexture2DEXT = Bind<FramebufferTexture2DEXT>("glFramebufferTexture2DEXT");
+			glDeleteFramebuffersEXT = Bind<DeleteFramebuffersEXT>("glDeleteFramebuffersEXT");
+			glGenRenderbuffersEXT = Bind<GenRenderbuffersEXT>("glGenRenderbuffersEXT");
+			glBindRenderbufferEXT = Bind<BindRenderbufferEXT>("glBindRenderbufferEXT");
+			glRenderbufferStorageEXT = Bind<RenderbufferStorageEXT>("glRenderbufferStorageEXT");
+			glDeleteRenderbuffersEXT = Bind<DeleteRenderbuffersEXT>("glDeleteRenderbuffersEXT");
+			glFramebufferRenderbufferEXT = Bind<FramebufferRenderbufferEXT>("glFramebufferRenderbufferEXT");
+			glCheckFramebufferStatus = Bind<CheckFramebufferStatus>("glCheckFramebufferStatus");
+		}
+
+		static T Bind<T>(string name)
+		{
+			return (T)(object)Marshal.GetDelegateForFunctionPointer(SDL.SDL_GL_GetProcAddress(name), typeof(T));
+		}
+	}
+}
--- a/OpenRA.Platforms.Default/OpenRA.Platforms.Default.csproj
+++ b/OpenRA.Platforms.Default/OpenRA.Platforms.Default.csproj
@@ -53,6 +53,7 @@
    <Compile Include="ThreadAffine.cs" />
    <Compile Include="VertexBuffer.cs" />
    <Compile Include="OpenAlSoundEngine.cs" />
+    <Compile Include="OpenGL.cs" />
  </ItemGroup>
  <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
  <ItemGroup>
--- a/OpenRA.Platforms.Default/Sdl2GraphicsDevice.cs
+++ b/OpenRA.Platforms.Default/Sdl2GraphicsDevice.cs
@@ -15,8 +15,6 @@ using System.Runtime.InteropServices;
 using System.Threading;
 using OpenRA;
 using OpenRA.Graphics;
-using OpenTK.Graphics;
-using OpenTK.Graphics.OpenGL;
 using SDL2;

 namespace OpenRA.Platforms.Default
@@ -78,9 +76,7 @@ namespace OpenRA.Platforms.Default
 			if (context == IntPtr.Zero || SDL.SDL_GL_MakeCurrent(window, context) < 0)
 				throw new InvalidOperationException("Can not create OpenGL context. (Error: {0})".F(SDL.SDL_GetError()));

-			GraphicsContext.CurrentContext = context;
-
-			GL.LoadAll();
+			OpenGL.LoadDelegates();
 			ErrorHandler.CheckGlVersion();
 			ErrorHandler.CheckGlError();

@@ -91,9 +87,9 @@ namespace OpenRA.Platforms.Default
 				throw new InvalidProgramException("Missing OpenGL extension GL_EXT_framebuffer_object. See graphics.log for details.");
 			}

-			GL.EnableVertexAttribArray(Shader.VertexPosAttributeIndex);
+			OpenGL.glEnableVertexAttribArray(Shader.VertexPosAttributeIndex);
 			ErrorHandler.CheckGlError();
-			GL.EnableVertexAttribArray(Shader.TexCoordAttributeIndex);
+			OpenGL.glEnableVertexAttribArray(Shader.TexCoordAttributeIndex);
 			ErrorHandler.CheckGlError();

 			SDL.SDL_SetModState(SDL.SDL_Keymod.KMOD_NONE);
@@ -203,13 +199,13 @@ namespace OpenRA.Platforms.Default
 			SDL.SDL_Quit();
 		}

-		static BeginMode ModeFromPrimitiveType(PrimitiveType pt)
+		static int ModeFromPrimitiveType(PrimitiveType pt)
 		{
 			switch (pt)
 			{
-				case PrimitiveType.PointList: return BeginMode.Points;
-				case PrimitiveType.LineList: return BeginMode.Lines;
-				case PrimitiveType.TriangleList: return BeginMode.Triangles;
+				case PrimitiveType.PointList: return OpenGL.GL_POINTS;
+				case PrimitiveType.LineList: return OpenGL.GL_LINES;
+				case PrimitiveType.TriangleList: return OpenGL.GL_TRIANGLES;
 			}

 			throw new NotImplementedException();
@@ -218,78 +214,78 @@ namespace OpenRA.Platforms.Default
 		public void DrawPrimitives(PrimitiveType pt, int firstVertex, int numVertices)
 		{
 			VerifyThreadAffinity();
-			GL.DrawArrays(ModeFromPrimitiveType(pt), firstVertex, numVertices);
+			OpenGL.glDrawArrays(ModeFromPrimitiveType(pt), firstVertex, numVertices);
 			ErrorHandler.CheckGlError();
 		}

 		public void Clear()
 		{
 			VerifyThreadAffinity();
-			GL.ClearColor(0, 0, 0, 1);
+			OpenGL.glClearColor(0, 0, 0, 1);
 			ErrorHandler.CheckGlError();
-			GL.Clear(ClearBufferMask.ColorBufferBit);
+			OpenGL.glClear(OpenGL.GL_COLOR_BUFFER_BIT);
 			ErrorHandler.CheckGlError();
 		}

 		public void EnableDepthBuffer()
 		{
 			VerifyThreadAffinity();
-			GL.Clear(ClearBufferMask.DepthBufferBit);
+			OpenGL.glClear(OpenGL.GL_DEPTH_BUFFER_BIT);
 			ErrorHandler.CheckGlError();
-			GL.Enable(EnableCap.DepthTest);
+			OpenGL.glEnable(OpenGL.GL_DEPTH_TEST);
 			ErrorHandler.CheckGlError();
 		}

 		public void DisableDepthBuffer()
 		{
 			VerifyThreadAffinity();
-			GL.Disable(EnableCap.DepthTest);
+			OpenGL.glDisable(OpenGL.GL_DEPTH_TEST);
 			ErrorHandler.CheckGlError();
 		}

 		public void SetBlendMode(BlendMode mode)
 		{
 			VerifyThreadAffinity();
-			GL.BlendEquation(BlendEquationMode.FuncAdd);
+			OpenGL.glBlendEquation(OpenGL.GL_FUNC_ADD);
 			ErrorHandler.CheckGlError();

 			switch (mode)
 			{
 				case BlendMode.None:
-					GL.Disable(EnableCap.Blend);
+					OpenGL.glDisable(OpenGL.GL_BLEND);
 					break;
 				case BlendMode.Alpha:
-					GL.Enable(EnableCap.Blend);
+					OpenGL.glEnable(OpenGL.GL_BLEND);
 					ErrorHandler.CheckGlError();
-					GL.BlendFunc(BlendingFactorSrc.One, BlendingFactorDest.OneMinusSrcAlpha);
+					OpenGL.glBlendFunc(OpenGL.GL_ONE, OpenGL.GL_ONE_MINUS_SRC_ALPHA);
 					break;
 				case BlendMode.Additive:
 				case BlendMode.Subtractive:
-					GL.Enable(EnableCap.Blend);
+					OpenGL.glEnable(OpenGL.GL_BLEND);
 					ErrorHandler.CheckGlError();
-					GL.BlendFunc(BlendingFactorSrc.One, BlendingFactorDest.One);
+					OpenGL.glBlendFunc(OpenGL.GL_ONE, OpenGL.GL_ONE);
 					if (mode == BlendMode.Subtractive)
 					{
 						ErrorHandler.CheckGlError();
-						GL.BlendEquation(BlendEquationMode.FuncReverseSubtract);
+						OpenGL.glBlendEquation(OpenGL.GL_FUNC_REVERSE_SUBTRACT);
 					}

 					break;
 				case BlendMode.Multiply:
-					GL.Enable(EnableCap.Blend);
+					OpenGL.glEnable(OpenGL.GL_BLEND);
 					ErrorHandler.CheckGlError();
-					GL.BlendFunc(BlendingFactorSrc.DstColor, BlendingFactorDest.OneMinusSrcAlpha);
+					OpenGL.glBlendFunc(OpenGL.GL_DST_COLOR, OpenGL.GL_ONE_MINUS_SRC_ALPHA);
 					ErrorHandler.CheckGlError();
 					break;
 				case BlendMode.Multiplicative:
-					GL.Enable(EnableCap.Blend);
+					OpenGL.glEnable(OpenGL.GL_BLEND);
 					ErrorHandler.CheckGlError();
-					GL.BlendFunc(BlendingFactorSrc.Zero, BlendingFactorDest.SrcColor);
+					OpenGL.glBlendFunc(OpenGL.GL_ZERO, OpenGL.GL_SRC_COLOR);
 					break;
 				case BlendMode.DoubleMultiplicative:
-					GL.Enable(EnableCap.Blend);
+					OpenGL.glEnable(OpenGL.GL_BLEND);
 					ErrorHandler.CheckGlError();
-					GL.BlendFunc(BlendingFactorSrc.DstColor, BlendingFactorDest.SrcColor);
+					OpenGL.glBlendFunc(OpenGL.GL_DST_COLOR, OpenGL.GL_SRC_COLOR);
 					break;
 			}

@@ -318,16 +314,16 @@ namespace OpenRA.Platforms.Default
 			if (height < 0)
 				height = 0;

-			GL.Scissor(left, WindowSize.Height - (top + height), width, height);
+			OpenGL.glScissor(left, WindowSize.Height - (top + height), width, height);
 			ErrorHandler.CheckGlError();
-			GL.Enable(EnableCap.ScissorTest);
+			OpenGL.glEnable(OpenGL.GL_SCISSOR_TEST);
 			ErrorHandler.CheckGlError();
 		}

 		public void DisableScissor()
 		{
 			VerifyThreadAffinity();
-			GL.Disable(EnableCap.ScissorTest);
+			OpenGL.glDisable(OpenGL.GL_SCISSOR_TEST);
 			ErrorHandler.CheckGlError();
 		}

@@ -338,15 +334,15 @@ namespace OpenRA.Platforms.Default
 			var data = bitmap.LockBits(rect,
 				System.Drawing.Imaging.ImageLockMode.WriteOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);

-			GL.PushClientAttrib(ClientAttribMask.ClientPixelStoreBit);
+			OpenGL.glPushClientAttrib(OpenGL.GL_CLIENT_PIXEL_STORE_BIT);

-			GL.PixelStore(PixelStoreParameter.PackRowLength, data.Stride / 4f);
-			GL.PixelStore(PixelStoreParameter.PackAlignment, 1);
+			OpenGL.glPixelStoref(OpenGL.GL_PACK_ROW_LENGTH, data.Stride / 4f);
+			OpenGL.glPixelStoref(OpenGL.GL_PACK_ALIGNMENT, 1);

-			GL.ReadPixels(rect.X, rect.Y, rect.Width, rect.Height, PixelFormat.Bgra, PixelType.UnsignedByte, data.Scan0);
-			GL.Finish();
+			OpenGL.glReadPixels(rect.X, rect.Y, rect.Width, rect.Height, OpenGL.GL_BGRA, OpenGL.GL_UNSIGNED_BYTE, data.Scan0);
+			OpenGL.glFinish();

-			GL.PopClientAttrib();
+			OpenGL.glPopClientAttrib();

 			bitmap.UnlockBits(data);

--- a/OpenRA.Platforms.Default/Shader.cs
+++ b/OpenRA.Platforms.Default/Shader.cs
@@ -12,7 +12,6 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Text;
-using OpenTK.Graphics.OpenGL;

 namespace OpenRA.Platforms.Default
 {
@@ -23,32 +22,35 @@ namespace OpenRA.Platforms.Default

 		readonly Dictionary<string, int> samplers = new Dictionary<string, int>();
 		readonly Dictionary<int, ITexture> textures = new Dictionary<int, ITexture>();
-		readonly int program;
+		readonly uint program;

-		protected int CompileShaderObject(ShaderType type, string name)
+		protected uint CompileShaderObject(int type, string name)
 		{
-			var ext = type == ShaderType.VertexShader ? "vert" : "frag";
+			var ext = type == OpenGL.GL_VERTEX_SHADER ? "vert" : "frag";
 			var filename = Path.Combine(Platform.GameDir, "glsl", name + "." + ext);
 			var code = File.ReadAllText(filename);

-			var shader = GL.CreateShader(type);
+			var shader = OpenGL.glCreateShader(type);
 			ErrorHandler.CheckGlError();
-			GL.ShaderSource(shader, code);
+			unsafe
+			{
+				var length = code.Length;
+				OpenGL.glShaderSource(shader, 1, new string[] { code }, new IntPtr(&length));
+			}
+
 			ErrorHandler.CheckGlError();
-			GL.CompileShader(shader);
+			OpenGL.glCompileShader(shader);
 			ErrorHandler.CheckGlError();
 			int success;
-			GL.GetShader(shader, ShaderParameter.CompileStatus, out success);
+			OpenGL.glGetShaderiv(shader, OpenGL.GL_COMPILE_STATUS, out success);
 			ErrorHandler.CheckGlError();
-			if (success == (int)All.False)
+			if (success == (int)OpenGL.GL_FALSE)
 			{
 				int len;
-				GL.GetShader(shader, ShaderParameter.InfoLogLength, out len);
+				OpenGL.glGetShaderiv(shader, OpenGL.GL_INFO_LOG_LENGTH, out len);
 				var log = new StringBuilder(len);
-				unsafe
-				{
-					GL.GetShaderInfoLog(shader, len, null, log);
-				}
+				int length;
+				OpenGL.glGetShaderInfoLog(shader, len, out length, log);

 				Log.Write("graphics", "GL Info Log:\n{0}", log.ToString());
 				throw new InvalidProgramException("Compile error in shader object '{0}'".F(filename));
@@ -59,66 +61,65 @@ namespace OpenRA.Platforms.Default

 		public Shader(string name)
 		{
-			var vertexShader = CompileShaderObject(ShaderType.VertexShader, name);
-			var fragmentShader = CompileShaderObject(ShaderType.FragmentShader, name);
+			var vertexShader = CompileShaderObject(OpenGL.GL_VERTEX_SHADER, name);
+			var fragmentShader = CompileShaderObject(OpenGL.GL_FRAGMENT_SHADER, name);

 			// Assemble program
-			program = GL.CreateProgram();
+			program = OpenGL.glCreateProgram();
 			ErrorHandler.CheckGlError();

-			GL.BindAttribLocation(program, VertexPosAttributeIndex, "aVertexPosition");
+			OpenGL.glBindAttribLocation(program, VertexPosAttributeIndex, "aVertexPosition");
 			ErrorHandler.CheckGlError();
-			GL.BindAttribLocation(program, TexCoordAttributeIndex, "aVertexTexCoord");
+			OpenGL.glBindAttribLocation(program, TexCoordAttributeIndex, "aVertexTexCoord");
 			ErrorHandler.CheckGlError();

-			GL.AttachShader(program, vertexShader);
+			OpenGL.glAttachShader(program, vertexShader);
 			ErrorHandler.CheckGlError();
-			GL.AttachShader(program, fragmentShader);
+			OpenGL.glAttachShader(program, fragmentShader);
 			ErrorHandler.CheckGlError();

-			GL.LinkProgram(program);
+			OpenGL.glLinkProgram(program);
 			ErrorHandler.CheckGlError();
 			int success;
-			GL.GetProgram(program, ProgramParameter.LinkStatus, out success);
+			OpenGL.glGetProgramiv(program, OpenGL.GL_LINK_STATUS, out success);
 			ErrorHandler.CheckGlError();
-			if (success == (int)All.False)
+			if (success == (int)OpenGL.GL_FALSE)
 			{
 				int len;
-				GL.GetProgram(program, ProgramParameter.InfoLogLength, out len);
-				var log = new StringBuilder(len);
-				unsafe
-				{
-					GL.GetProgramInfoLog(program, len, null, log);
-				}
+				OpenGL.glGetProgramiv(program, OpenGL.GL_INFO_LOG_LENGTH, out len);

+				var log = new StringBuilder(len);
+				int length;
+				OpenGL.glGetProgramInfoLog(program, len, out length, log);
 				Log.Write("graphics", "GL Info Log:\n{0}", log.ToString());
 				throw new InvalidProgramException("Link error in shader program '{0}'".F(name));
 			}

-			GL.UseProgram(program);
+			OpenGL.glUseProgram(program);
 			ErrorHandler.CheckGlError();

 			int numUniforms;
-			GL.GetProgram(program, ProgramParameter.ActiveUniforms, out numUniforms);
+			OpenGL.glGetProgramiv(program, OpenGL.GL_ACTIVE_UNIFORMS, out numUniforms);
+
 			ErrorHandler.CheckGlError();

 			var nextTexUnit = 0;
 			for (var i = 0; i < numUniforms; i++)
 			{
 				int length, size;
-				ActiveUniformType type;
+				int type;
 				var sb = new StringBuilder(128);
-				GL.GetActiveUniform(program, i, 128, out length, out size, out type, sb);
+				OpenGL.glGetActiveUniform(program, i, 128, out length, out size, out type, sb);
 				var sampler = sb.ToString();
 				ErrorHandler.CheckGlError();

-				if (type == ActiveUniformType.Sampler2D)
+				if (type == OpenGL.GL_SAMPLER_2D)
 				{
 					samplers.Add(sampler, nextTexUnit);

-					var loc = GL.GetUniformLocation(program, sampler);
+					var loc = OpenGL.glGetUniformLocation(program, sampler);
 					ErrorHandler.CheckGlError();
-					GL.Uniform1(loc, nextTexUnit);
+					OpenGL.glUniform1i(loc, nextTexUnit);
 					ErrorHandler.CheckGlError();

 					nextTexUnit++;
@@ -129,13 +130,13 @@ namespace OpenRA.Platforms.Default
 		public void Render(Action a)
 		{
 			VerifyThreadAffinity();
-			GL.UseProgram(program);
+			OpenGL.glUseProgram(program);

 			// bind the textures
 			foreach (var kv in textures)
 			{
-				GL.ActiveTexture(TextureUnit.Texture0 + kv.Key);
-				GL.BindTexture(TextureTarget.Texture2D, ((Texture)kv.Value).ID);
+				OpenGL.glActiveTexture(OpenGL.GL_TEXTURE0 + kv.Key);
+				OpenGL.glBindTexture(OpenGL.GL_TEXTURE_2D, ((Texture)kv.Value).ID);
 			}

 			ErrorHandler.CheckGlError();
@@ -157,48 +158,55 @@ namespace OpenRA.Platforms.Default
 		public void SetBool(string name, bool value)
 		{
 			VerifyThreadAffinity();
-			GL.UseProgram(program);
+			OpenGL.glUseProgram(program);
 			ErrorHandler.CheckGlError();
-			var param = GL.GetUniformLocation(program, name);
+			var param = OpenGL.glGetUniformLocation(program, name);
 			ErrorHandler.CheckGlError();
-			GL.Uniform1(param, value ? 1 : 0);
+			OpenGL.glUniform1i(param, value ? 1 : 0);
 			ErrorHandler.CheckGlError();
 		}

 		public void SetVec(string name, float x)
 		{
 			VerifyThreadAffinity();
-			GL.UseProgram(program);
+			OpenGL.glUseProgram(program);
 			ErrorHandler.CheckGlError();
-			var param = GL.GetUniformLocation(program, name);
+			var param = OpenGL.glGetUniformLocation(program, name);
 			ErrorHandler.CheckGlError();
-			GL.Uniform1(param, x);
+			OpenGL.glUniform1f(param, x);
 			ErrorHandler.CheckGlError();
 		}

 		public void SetVec(string name, float x, float y)
 		{
 			VerifyThreadAffinity();
-			GL.UseProgram(program);
+			OpenGL.glUseProgram(program);
 			ErrorHandler.CheckGlError();
-			var param = GL.GetUniformLocation(program, name);
+			var param = OpenGL.glGetUniformLocation(program, name);
 			ErrorHandler.CheckGlError();
-			GL.Uniform2(param, x, y);
+			OpenGL.glUniform2f(param, x, y);
 			ErrorHandler.CheckGlError();
 		}

 		public void SetVec(string name, float[] vec, int length)
 		{
 			VerifyThreadAffinity();
-			var param = GL.GetUniformLocation(program, name);
+			var param = OpenGL.glGetUniformLocation(program, name);
 			ErrorHandler.CheckGlError();
-			switch (length)
+			unsafe
 			{
-				case 1: GL.Uniform1(param, 1, vec); break;
-				case 2: GL.Uniform2(param, 1, vec); break;
-				case 3: GL.Uniform3(param, 1, vec); break;
-				case 4: GL.Uniform4(param, 1, vec); break;
-				default: throw new InvalidDataException("Invalid vector length");
+				fixed (float* pVec = vec)
+				{
+					var ptr = new IntPtr(pVec);
+					switch (length)
+					{
+						case 1: OpenGL.glUniform1fv(param, 1, ptr); break;
+						case 2: OpenGL.glUniform2fv(param, 1, ptr); break;
+						case 3: OpenGL.glUniform3fv(param, 1, ptr); break;
+						case 4: OpenGL.glUniform4fv(param, 1, ptr); break;
+						default: throw new InvalidDataException("Invalid vector length");
+					}
+				}
 			}

 			ErrorHandler.CheckGlError();
@@ -210,11 +218,17 @@ namespace OpenRA.Platforms.Default
 			if (mtx.Length != 16)
 				throw new InvalidDataException("Invalid 4x4 matrix");

-			GL.UseProgram(program);
+			OpenGL.glUseProgram(program);
 			ErrorHandler.CheckGlError();
-			var param = GL.GetUniformLocation(program, name);
+			var param = OpenGL.glGetUniformLocation(program, name);
 			ErrorHandler.CheckGlError();
-			GL.UniformMatrix4(param, 1, false, mtx);
+
+			unsafe
+			{
+				fixed (float* pMtx = mtx)
+					OpenGL.glUniformMatrix4fv(param, 1, false, new IntPtr(pMtx));
+			}
+
 			ErrorHandler.CheckGlError();
 		}
 	}
--- a/OpenRA.Platforms.Default/Texture.cs
+++ b/OpenRA.Platforms.Default/Texture.cs
@@ -12,16 +12,15 @@ using System;
 using System.Drawing;
 using System.Drawing.Imaging;
 using System.IO;
-using OpenTK.Graphics.OpenGL;

 namespace OpenRA.Platforms.Default
 {
 	sealed class Texture : ThreadAffine, ITexture
 	{
-		int texture;
+		uint texture;
 		TextureScaleFilter scaleFilter;

-		public int ID { get { return texture; } }
+		public uint ID { get { return texture; } }
 		public Size Size { get; private set; }

 		bool disposed;
@@ -46,13 +45,13 @@ namespace OpenRA.Platforms.Default

 		public Texture()
 		{
-			GL.GenTextures(1, out texture);
+			OpenGL.glGenTextures(1, out texture);
 			ErrorHandler.CheckGlError();
 		}

 		public Texture(Bitmap bitmap)
 		{
-			GL.GenTextures(1, out texture);
+			OpenGL.glGenTextures(1, out texture);
 			ErrorHandler.CheckGlError();
 			SetData(bitmap);
 		}
@@ -60,23 +59,23 @@ namespace OpenRA.Platforms.Default
 		void PrepareTexture()
 		{
 			ErrorHandler.CheckGlError();
-			GL.BindTexture(TextureTarget.Texture2D, texture);
+			OpenGL.glBindTexture(OpenGL.GL_TEXTURE_2D, texture);
 			ErrorHandler.CheckGlError();

-			var filter = scaleFilter == TextureScaleFilter.Linear ? (int)TextureMinFilter.Linear : (int)TextureMinFilter.Nearest;
-			GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, filter);
+			var filter = scaleFilter == TextureScaleFilter.Linear ? OpenGL.GL_LINEAR : OpenGL.GL_NEAREST;
+			OpenGL.glTexParameteri(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_MAG_FILTER, (int)filter);
 			ErrorHandler.CheckGlError();
-			GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, filter);
+			OpenGL.glTexParameteri(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_MIN_FILTER, (int)filter);
 			ErrorHandler.CheckGlError();

-			GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, (float)TextureWrapMode.ClampToEdge);
+			OpenGL.glTexParameterf(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_WRAP_S, (float)OpenGL.GL_CLAMP_TO_EDGE);
 			ErrorHandler.CheckGlError();
-			GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapT, (float)TextureWrapMode.ClampToEdge);
+			OpenGL.glTexParameterf(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_WRAP_T, (float)OpenGL.GL_CLAMP_TO_EDGE);
 			ErrorHandler.CheckGlError();

-			GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureBaseLevel, 0);
+			OpenGL.glTexParameteri(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_BASE_LEVEL, 0);
 			ErrorHandler.CheckGlError();
-			GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMaxLevel, 0);
+			OpenGL.glTexParameteri(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_MAX_LEVEL, 0);
 			ErrorHandler.CheckGlError();
 		}

@@ -93,8 +92,8 @@ namespace OpenRA.Platforms.Default
 				{
 					var intPtr = new IntPtr((void*)ptr);
 					PrepareTexture();
-					GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba8, width, height,
-						0, OpenTK.Graphics.OpenGL.PixelFormat.Bgra, PixelType.UnsignedByte, intPtr);
+					OpenGL.glTexImage2D(OpenGL.GL_TEXTURE_2D, 0, OpenGL.GL_RGBA8, width, height,
+						0, OpenGL.GL_BGRA, OpenGL.GL_UNSIGNED_BYTE, intPtr);
 					ErrorHandler.CheckGlError();
 				}
 			}
@@ -117,8 +116,8 @@ namespace OpenRA.Platforms.Default
 				{
 					var intPtr = new IntPtr((void*)ptr);
 					PrepareTexture();
-					GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba8, width, height,
-						0, OpenTK.Graphics.OpenGL.PixelFormat.Bgra, PixelType.UnsignedByte, intPtr);
+					OpenGL.glTexImage2D(OpenGL.GL_TEXTURE_2D, 0, OpenGL.GL_RGBA8, width, height,
+						0, OpenGL.GL_BGRA, OpenGL.GL_UNSIGNED_BYTE, intPtr);
 					ErrorHandler.CheckGlError();
 				}
 			}
@@ -141,8 +140,8 @@ namespace OpenRA.Platforms.Default
 					ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);

 				PrepareTexture();
-				GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba8, bits.Width, bits.Height,
-					0, OpenTK.Graphics.OpenGL.PixelFormat.Bgra, PixelType.UnsignedByte, bits.Scan0); // TODO: weird strides
+				OpenGL.glTexImage2D(OpenGL.GL_TEXTURE_2D, 0, OpenGL.GL_RGBA8, bits.Width, bits.Height,
+					0, OpenGL.GL_BGRA, OpenGL.GL_UNSIGNED_BYTE, bits.Scan0); // TODO: weird strides
 				ErrorHandler.CheckGlError();
 				bitmap.UnlockBits(bits);
 			}
@@ -159,13 +158,14 @@ namespace OpenRA.Platforms.Default
 			var data = new byte[4 * Size.Width * Size.Height];

 			ErrorHandler.CheckGlError();
-			GL.BindTexture(TextureTarget.Texture2D, texture);
+			OpenGL.glBindTexture(OpenGL.GL_TEXTURE_2D, texture);
 			unsafe
 			{
 				fixed (byte* ptr = &data[0])
 				{
 					var intPtr = new IntPtr((void*)ptr);
-					GL.GetTexImage(TextureTarget.Texture2D, 0, OpenTK.Graphics.OpenGL.PixelFormat.Bgra, PixelType.UnsignedByte, intPtr);
+					OpenGL.glGetTexImage(OpenGL.GL_TEXTURE_2D, 0, OpenGL.GL_BGRA,
+						OpenGL.GL_UNSIGNED_BYTE, intPtr);
 				}
 			}

@@ -181,8 +181,8 @@ namespace OpenRA.Platforms.Default

 			Size = new Size(width, height);
 			PrepareTexture();
-			GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba8, width, height,
-				0, OpenTK.Graphics.OpenGL.PixelFormat.Bgra, PixelType.UnsignedByte, IntPtr.Zero);
+			OpenGL.glTexImage2D(OpenGL.GL_TEXTURE_2D, 0, OpenGL.GL_RGBA8, width, height,
+				0, OpenGL.GL_BGRA, OpenGL.GL_UNSIGNED_BYTE, IntPtr.Zero);
 			ErrorHandler.CheckGlError();
 		}

@@ -202,7 +202,7 @@ namespace OpenRA.Platforms.Default
 			if (disposed)
 				return;
 			disposed = true;
-			GL.DeleteTextures(1, ref texture);
+			OpenGL.glDeleteTextures(1, ref texture);
 		}
 	}
 }
--- a/OpenRA.Platforms.Default/VertexBuffer.cs
+++ b/OpenRA.Platforms.Default/VertexBuffer.cs
@@ -10,7 +10,6 @@

 using System;
 using System.Runtime.InteropServices;
-using OpenTK.Graphics.OpenGL;

 namespace OpenRA.Platforms.Default
 {
@@ -18,18 +17,28 @@ namespace OpenRA.Platforms.Default
 			where T : struct
 	{
 		static readonly int VertexSize = Marshal.SizeOf(typeof(T));
-		int buffer;
+		uint buffer;
 		bool disposed;

 		public VertexBuffer(int size)
 		{
-			GL.GenBuffers(1, out buffer);
+			OpenGL.glGenBuffers(1, out buffer);
 			ErrorHandler.CheckGlError();
 			Bind();
-			GL.BufferData(BufferTarget.ArrayBuffer,
-				new IntPtr(VertexSize * size),
-				new T[size],
-				BufferUsageHint.DynamicDraw);
+
+			var ptr = GCHandle.Alloc(new T[size], GCHandleType.Pinned);
+			try
+			{
+				OpenGL.glBufferData(OpenGL.GL_ARRAY_BUFFER,
+					new IntPtr(VertexSize * size),
+					ptr.AddrOfPinnedObject(),
+					OpenGL.GL_DYNAMIC_DRAW);
+			}
+			finally
+			{
+				ptr.Free();
+			}
+
 			ErrorHandler.CheckGlError();
 		}

@@ -41,17 +50,27 @@ namespace OpenRA.Platforms.Default
 		public void SetData(T[] data, int start, int length)
 		{
 			Bind();
-			GL.BufferSubData(BufferTarget.ArrayBuffer,
-				new IntPtr(VertexSize * start),
-				new IntPtr(VertexSize * length),
-				data);
+
+			var ptr = GCHandle.Alloc(data, GCHandleType.Pinned);
+			try
+			{
+				OpenGL.glBufferSubData(OpenGL.GL_ARRAY_BUFFER,
+					new IntPtr(VertexSize * start),
+					new IntPtr(VertexSize * length),
+					ptr.AddrOfPinnedObject());
+			}
+			finally
+			{
+				ptr.Free();
+			}
+
 			ErrorHandler.CheckGlError();
 		}

 		public void SetData(IntPtr data, int start, int length)
 		{
 			Bind();
-			GL.BufferSubData(BufferTarget.ArrayBuffer,
+			OpenGL.glBufferSubData(OpenGL.GL_ARRAY_BUFFER,
 				new IntPtr(VertexSize * start),
 				new IntPtr(VertexSize * length),
 				data);
@@ -61,11 +80,11 @@ namespace OpenRA.Platforms.Default
 		public void Bind()
 		{
 			VerifyThreadAffinity();
-			GL.BindBuffer(BufferTarget.ArrayBuffer, buffer);
+			OpenGL.glBindBuffer(OpenGL.GL_ARRAY_BUFFER, buffer);
 			ErrorHandler.CheckGlError();
-			GL.VertexAttribPointer(Shader.VertexPosAttributeIndex, 3, VertexAttribPointerType.Float, false, VertexSize, IntPtr.Zero);
+			OpenGL.glVertexAttribPointer(Shader.VertexPosAttributeIndex, 3, OpenGL.GL_FLOAT, false, VertexSize, IntPtr.Zero);
 			ErrorHandler.CheckGlError();
-			GL.VertexAttribPointer(Shader.TexCoordAttributeIndex, 4, VertexAttribPointerType.Float, false, VertexSize, new IntPtr(12));
+			OpenGL.glVertexAttribPointer(Shader.TexCoordAttributeIndex, 4, OpenGL.GL_FLOAT, false, VertexSize, new IntPtr(12));
 			ErrorHandler.CheckGlError();
 		}

@@ -85,7 +104,7 @@ namespace OpenRA.Platforms.Default
 			if (disposed)
 				return;
 			disposed = true;
-			GL.DeleteBuffers(1, ref buffer);
+			OpenGL.glDeleteBuffers(1, ref buffer);
 		}
 	}
 }