check for OpenGL version 2.0+

OpenRA.Renderer.Sdl2/ErrorHandler.cs

@@ -16,6 +16,24 @@ namespace OpenRA.Renderer.Sdl2
 {
 	public static class ErrorHandler
 	{
+		static Version OpenGLversion;
+
+		public static void CheckGlVersion()
+		{
+			var version = GL.GetString(StringName.Version).Split(' ')[0].Split('.');
+			int major;
+			int.TryParse(version[0], out major);
+			int minor;
+			int.TryParse(version[1], out minor);
+			Console.WriteLine("Detected OpenGL version: {0}.{1}".F(major, minor));
+			OpenGLversion = new Version(major, minor);
+			if (major < 2)
+			{
+				WriteGraphicsLog("OpenRA requires OpenGL version 2.0 or greater.");
+				throw new InvalidProgramException("OpenGL Version Error: See graphics.log for details.");
+			}
+		}
+
 		public static void CheckGlError()
 		{
 			var n = GL.GetError();
@@ -40,6 +58,11 @@ namespace OpenRA.Renderer.Sdl2
 			}
 			Log.Write("graphics",  "Renderer: {0}", GL.GetString(StringName.Renderer));
 			Log.Write("graphics",  "GL Version: {0}", GL.GetString(StringName.Version));
+			if (OpenGLversion.Major < 2)
+			{
+				Log.Write("graphics", "Note: OpenRA requires OpenGL version 2.0+.\n"
+					+"Please update your graphics card drivers to the latest version.\n");
+			}
 			Log.Write("graphics",  "Shader Version: {0}", GL.GetString(StringName.ShadingLanguageVersion));
 			Log.Write("graphics", "Available extensions:");
 			Log.Write("graphics", GL.GetString(StringName.Extensions));

OpenRA.Renderer.Sdl2/Sdl2GraphicsDevice.cs

@@ -79,6 +79,7 @@ namespace OpenRA.Renderer.Sdl2
 			context = SDL.SDL_GL_CreateContext(window);
 			SDL.SDL_GL_MakeCurrent(window, context);
 			GL.LoadAll();
+			ErrorHandler.CheckGlVersion();
 			ErrorHandler.CheckGlError();
 
 			if (SDL.SDL_GL_ExtensionSupported("GL_EXT_framebuffer_object") == SDL.SDL_bool.SDL_FALSE)