Began working on a graphical playground for testing.

Improved SDL exception class.

Engine code changes.

General progress.

src/SlatedGameToolkit.Framework/Exceptions/SDLException.cs

@@ -14,18 +14,21 @@ namespace SlatedGameToolkit.Framework.Exceptions
         /// Creates an SDL exception.
         /// </summary>
         /// <param name="Fetch">Whether or not to fetch the last error message that occurred in SDL.</param>
-        public SDLException(bool autoFlush = true) : base() {
+        public SDLException(bool autoFlush = true) : base(autoFlush ? SDL.SDL_GetError() : "SDL error has occurred.") {
             if (autoFlush) {
                 SDLMessage = SDL.SDL_GetError();
                 SDL.SDL_ClearError();
             }
         }
 
-        public SDLException(string message, Exception inner) : base(message, inner) {
-
+        public SDLException(string message, bool autoFlush = true) : base(message + " (" + (autoFlush ? SDL.SDL_GetError() : "SDL error has occurred.") + ")") {
+            if (autoFlush) {
+                SDLMessage = SDL.SDL_GetError();
+                SDL.SDL_ClearError();
+            }
         }
 
-        public SDLException(string message, bool autoFlush = true) : base(message) {
+        public SDLException(string message, Exception inner, bool autoFlush = true) : base(message + " (" + (autoFlush ? SDL.SDL_GetError() : "SDL error has occurred.") + ")", inner) {
             if (autoFlush) {
                 SDLMessage = SDL.SDL_GetError();
                 SDL.SDL_ClearError();

src/SlatedGameToolkit.Framework/GameEngine.cs

@@ -17,47 +17,69 @@ namespace SlatedGameToolkit.Framework {
         CreateLogger();
         private static readonly object ignitionLock = new object();
         private static Thread thread;
-        private static volatile bool exit = false, loopCompleted = true;
-        private static long updateDeltaTime = 50, frameDeltaTime = 0;
+        private static volatile bool exit = false, stopped = true;
+        private static volatile bool deltaChanged = true;
+        private static long updateDeltaTime = 25, frameDeltaTime = 16;
 
         /// <summary>
         /// The amount of updates per second.
         /// Is floored to milleseconds.
+        /// Maximum updates per second is 200.
         /// </summary>
         /// <value>The updates per second.</value>
         public static double UpdatesPerSecond {
             get {
-                return TimeSpan.FromMilliseconds(1 / updateDeltaTime).TotalSeconds;
+                return  1 / TimeSpan.FromMilliseconds(updateDeltaTime).TotalSeconds;
             }
             set {
-                Interlocked.Exchange(ref updateDeltaTime, (long) TimeSpan.FromSeconds(1 / value).TotalMilliseconds);
+                Interlocked.Exchange(ref updateDeltaTime, Math.Min(5, (long) TimeSpan.FromSeconds(1 / value).TotalMilliseconds));
+                deltaChanged = true;
             }
         }
 
         /// <summary>
         /// The target frames per second. Will not go above this number, but may dip below this number.
-        /// This value is floored to millesconds.
+        /// This value is floored to millesconds units.
+        /// Setting this to 0 renders as many frames as the system can handle.
+        /// Default is 60.
         /// </summary>
         /// <value>The target frames per second.</value>
         public static double targetFPS {
             get {
-                return TimeSpan.FromMilliseconds(1 / frameDeltaTime).TotalSeconds;
+                if (frameDeltaTime == 0) return 0;
+                return 1 / TimeSpan.FromMilliseconds(frameDeltaTime).TotalSeconds;
             }
             set {
+                if (value == 0) Interlocked.Exchange(ref frameDeltaTime, 0);
                 Interlocked.Exchange(ref frameDeltaTime, (long) TimeSpan.FromSeconds(1 / value).TotalMilliseconds);
+                deltaChanged = true;
+            }
+        }
+
+        public static bool Running {
+            get {
+                return !stopped;
             }
         }
 
         private static void Loop(Object o) {
             if (!(o is Manager)) throw new InternalFrameworkException(String.Format("Expected manager object for asynchronous loop. Got {0}", o));
             Manager manager = (Manager) o;
+            manager.initialize();
             long currentTime = DateTimeOffset.Now.ToUnixTimeMilliseconds();
             long timePassedFromLastUpdate = 0;
             long timePassedFromLastRender = 0;
-            loopCompleted = false;
+            long updateDeltaTime = 0;
+            long frameDeltaTime = 0;
+            stopped = false;
+            logger.Information("Game engine initiated.");
             while (!exit) {
-                long updateDeltaTime = Interlocked.Read(ref GameEngine.updateDeltaTime);
-                long frameDeltaTime = Interlocked.Read(ref GameEngine.frameDeltaTime);
+                if (deltaChanged) {
+                    updateDeltaTime = Interlocked.Read(ref GameEngine.updateDeltaTime);
+                    frameDeltaTime = Interlocked.Read(ref GameEngine.frameDeltaTime);
+                    deltaChanged = false;
+                }
+
                 long frameStart = DateTimeOffset.Now.ToUnixTimeMilliseconds();
                 long difference = frameStart - currentTime;
                 currentTime = frameStart;
@@ -74,8 +96,10 @@ namespace SlatedGameToolkit.Framework {
                     timePassedFromLastRender = 0;
                 }
             }
-            loopCompleted = true;
+            manager.Dispose();
+            stopped = true;
             SDL.SDL_Quit();
+            logger.Information("Game engine has stopped.");
         }
 
         /// <summary>
@@ -96,28 +120,25 @@ namespace SlatedGameToolkit.Framework {
         /// Requests to start the game engine. 
         /// </summary>
         /// <returns>True iff the engine is not already running.</returns>
-        private static bool Ignite(Manager manager) {
+        public static bool Ignite(Manager manager) {
             if (manager == null) throw new ArgumentNullException("manager");
             SDL.SDL_version SDLVersion;
             SDL.SDL_version SDLBuiltVersion;
             SDL.SDL_GetVersion(out SDLVersion);
             SDL.SDL_VERSION(out SDLBuiltVersion);
-            logger.Information(String.Format("Attempting to initiate game engine with SDL version: {0}", SDLVersion.ToString()));
-            if (SDL.SDL_VERSION_ATLEAST(SDLBuiltVersion.major, SDLBuiltVersion.minor, SDLBuiltVersion.patch)) {
-                logger.Warning(String.Format("Engine was designed with SDL version {0}, currently running on {1}", SDLVersion.ToString(), SDLBuiltVersion.ToString()));
+            logger.Information(String.Format("Attempting to initiate game engine with SDL version: {0}.{1}.{2}", SDLVersion.major, SDLVersion.minor, SDLVersion.patch));
+            if (!SDL.SDL_VERSION_ATLEAST(SDLBuiltVersion.major, SDLBuiltVersion.minor, SDLBuiltVersion.patch)) {
+                logger.Warning(String.Format("Engine was designed with SDL version {0}.{1}.{2}, currently running on {3}.{4}.{5}", SDLBuiltVersion.major, SDLBuiltVersion.minor, SDLBuiltVersion.patch, SDLVersion.major, SDLVersion.minor, SDLVersion.patch));
                 if (SDLVersion.major < 2) {
                     logger.Error("This engine was designed to work with SDL2. The version you're currently running is severely outdated.");
                     throw new FrameworkUsageException("Outdated SDL binaries.");
                 }
             }
             lock (ignitionLock) {
-                if (!loopCompleted) return false;
-                loopCompleted = false;
-
-                if (SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_MAJOR_VERSION, 3) < 0) throw new FrameworkSDLException();
-                if (SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_MINOR_VERSION, 1) < 0) throw new FrameworkSDLException();
-                if (SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_PROFILE_MASK, SDL.SDL_GLprofile.SDL_GL_CONTEXT_PROFILE_CORE) < 0) throw new FrameworkSDLException();
-
+                if (!stopped) {
+                    logger.Warning("Engine is already running.");
+                    return false;
+                }
                 exit = false;
                 if (SDL.SDL_Init(SDL.SDL_INIT_VIDEO) != 0) {
                     throw new FrameworkSDLException();
@@ -125,6 +146,11 @@ namespace SlatedGameToolkit.Framework {
                 if (SDL.SDL_Init(SDL.SDL_INIT_AUDIO) != 0) {
                     throw new FrameworkSDLException();
                 }
+
+                if (SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_MAJOR_VERSION, 3) < 0) throw new FrameworkSDLException();
+                if (SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_MINOR_VERSION, 1) < 0) throw new FrameworkSDLException();
+                if (SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_PROFILE_MASK, SDL.SDL_GLprofile.SDL_GL_CONTEXT_PROFILE_CORE) < 0) throw new FrameworkSDLException();
+
                 thread = new Thread(Loop);
                 thread.Start(manager);
                 return true;

src/SlatedGameToolkit.Framework/Graphics/Window/WindowHandle.cs

@@ -207,10 +207,14 @@ namespace SlatedGameToolkit.Framework.Graphics.Window
         /// Makes this window the window that is currently being drawn to.
         /// More specifically, it sets the OpenGL Context associated with this window to be the one
         /// that is actively receiving all OpenGL calls.
+        /// 
+        /// If the current context is already of this window, nothing happens.
         /// </summary>
         public void DrawToWindow() {
+            if (SDL.SDL_GL_GetCurrentContext() != glContext) {
                 SDL.SDL_GL_MakeCurrent(window, glContext);
             }
+        }
 
         /// <summary>
         /// Raises this window to be above other windows.

src/SlatedGameToolkit.Framework/Input/InputMatrix.cs

@@ -1,13 +0,0 @@
-using SDL2;
-
-namespace SlatedGameToolkit.Framework.Input
-{
-    internal class InputMatrix {
-        public void update() {
-            SDL.SDL_Event inputEvent;
-            while (SDL.SDL_PollEvent(out inputEvent) != 0) {
-                
-            }
-        }
-    }
-}

src/SlatedGameToolkit.Framework/StateSystem/Manager.cs

@@ -26,6 +26,10 @@ namespace SlatedGameToolkit.Framework.StateSystem
             if (!this.states.TryGetValue(initialState, out currentState)) throw new ArgumentException("The requested initial state name does not exist in the provided list of states.");
         }
 
+        internal void initialize() {
+            thread = Thread.CurrentThread;
+        }
+
         internal void update(double delta) {
             if (nextState != null) {
                 if (currentState.Deactivate() & nextState.Activate()) {

src/SlatedGameToolkit.Tools/Commands/GraphicalPlaygroundCommand.cs

@@ -0,0 +1,60 @@
+using SlatedGameToolkit.Framework;
+using SlatedGameToolkit.Framework.StateSystem;
+using SlatedGameToolkit.Tools.System;
+using SlatedGameToolkit.Tools.System.Interaction;
+using SlatedGameToolkit.Tools.Utilities.GraphicalPlayground;
+
+namespace SlatedGameToolkit.Tools.Commands
+{
+    public class GraphicalPlaygroundCommand : IInvocable
+    {
+        private readonly string[] invokers = new string[] {"playground"};
+
+        public bool Execute(IInteractable interactable, string[] args)
+        {
+            if (args.Length != 1) return false;
+            if (args[0].Equals("start")) {
+                if (GameEngine.Running) {
+                    interactable.Tell("Engine is already running!");
+                    return true;
+                }
+                Manager manager = new Manager("main state", new MainState());
+                GameEngine.Ignite(manager);
+                return true;
+            } else if (args[0].Equals("stop")) {
+                if (!GameEngine.Running) {
+                    interactable.Tell("Engine was never running!");
+                    return true;
+                }
+                GameEngine.Stop();
+                return true;
+            } else if (args[0].Equals("status")) {
+                interactable.Tell("Running: " + GameEngine.Running);
+                interactable.Tell("Target FPS: " + GameEngine.targetFPS);
+                interactable.Tell("Target Update Rate: " + GameEngine.UpdatesPerSecond);
+                return true;
+            }
+            return false;
+        }
+
+        public string getDescription()
+        {
+            return "Starts and stops the graphical playground.";
+        }
+
+        public string[] GetInvokers()
+        {
+            return invokers;
+        }
+
+        public string getUsage(string arg)
+        {
+            return "Usage: \"playground [start | stop | status]\" the required argument being whether to start, stop or get the current status of the game engine.";
+        }
+
+        public void Dispose()
+        {
+            GameEngine.Stop();
+        }
+    }
+}

src/SlatedGameToolkit.Tools/Commands/HelpCommand.cs

@@ -52,5 +52,10 @@ namespace SlatedGameToolkit.Tools.Commands
         {
             return invokers;
         }
+
+        public void Dispose()
+        {
+            
+        }
     }
 }

src/SlatedGameToolkit.Tools/Commands/StopCommand.cs

@@ -27,5 +27,9 @@ namespace SlatedGameToolkit.Tools.Commands
         {
             return invokers;
         }
+
+        public void Dispose()
+        {
+        }
     }
 }

src/SlatedGameToolkit.Tools/Program.cs

@@ -11,8 +11,10 @@ namespace SlatedGameToolkit.Tools
         static private bool running;
         static void Main(string[] args)
         {
-            CommandMap commands = new CommandMap(new StopCommand());
+            CommandMap commands = new CommandMap();
+            commands.Add(new StopCommand());
             commands.Add(new HelpCommand(commands));
+            commands.Add(new GraphicalPlaygroundCommand());
             CommandProcessor processor = new CommandProcessor("The command \"{input}\" was not understood. Please type \"help\" for more information.", commands);
             AssemblyName name = Assembly.GetExecutingAssembly().GetName();
             ConsoleInteraction consoleInteracter = new ConsoleInteraction("Tools");
@@ -24,6 +26,7 @@ namespace SlatedGameToolkit.Tools
                 processor.Process(consoleInteracter);
             }
             consoleInteracter.Tell("Exiting tool.");
+            commands.Dispose();
         }
 
         public static void Stop() {

src/SlatedGameToolkit.Tools/System/CommandMap.cs

@@ -5,7 +5,7 @@ using SlatedGameToolkit.Tools.System.Interaction;
 
 namespace SlatedGameToolkit.Tools.System
 {
-    public class CommandMap : ICollection<IInvocable> {
+    public class CommandMap : ICollection<IInvocable>, IDisposable {
         Dictionary<string, IInvocable> invocations;
         HashSet<IInvocable> values;
 
@@ -79,5 +79,17 @@ namespace SlatedGameToolkit.Tools.System
             values.Remove(item);
             return true;
         }
+
+        public void Dispose()
+        {
+            foreach (IInvocable invocable in this)
+            {
+                invocable.Dispose();
+            }
+        }
+
+        ~CommandMap() {
+            Dispose();
+        }
     }
 }

src/SlatedGameToolkit.Tools/System/IInvocable.cs

@@ -1,8 +1,9 @@
+using System;
 using SlatedGameToolkit.Tools.System.Interaction;
 
 namespace SlatedGameToolkit.Tools.System
 {
-    public interface IInvocable
+    public interface IInvocable : IDisposable
     {
         /// <summary>
         /// Invokers are the strings that should invoke this command.

src/SlatedGameToolkit.Tools/System/Interaction/IInteractable.cs

@@ -4,7 +4,6 @@ namespace SlatedGameToolkit.Tools.System.Interaction
     {
         void Tell(string message);
         void Separate();
-
         string Listen();
     }
 }

src/SlatedGameToolkit.Tools/Utilities/GraphicalPlayground/MainState.cs

@@ -0,0 +1,40 @@
+using SlatedGameToolkit.Framework.StateSystem;
+using SlatedGameToolkit.Framework.StateSystem.States;
+
+namespace SlatedGameToolkit.Tools.Utilities.GraphicalPlayground
+{
+    public class MainState : IState
+    {
+        public bool Activate()
+        {
+            return true;
+        }
+
+        public bool Deactivate()
+        {
+            return true;
+        }
+
+        public void Dispose()
+        {
+        }
+
+        public string getName()
+        {
+            return "main state";
+        }
+
+        public void Initialize(Manager manager)
+        {
+
+        }
+
+        public void Render(double delta)
+        {
+        }
+
+        public void Update(double delta)
+        {
+        }
+    }
+}