Add API to let users pick OpenGL version

src/Windowing/OpenToolkit.Windowing.Common/Enums/ContextAPI.cs

@@ -0,0 +1,47 @@
+//
+// ContextAPI.cs
+//
+// Copyright (C) 2019 OpenTK
+//
+// This software may be modified and distributed under the terms
+// of the MIT license. See the LICENSE file for details.
+//
+
+namespace OpenToolkit.Windowing.Common
+{
+    /// <summary>
+    /// Describes the graphics API you want the context to use.
+    /// </summary>
+    public enum ContextAPI
+    {
+        /// <summary>
+        /// Indicates that an API has not been specifically requested for context creation.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// This is primarily for integrating an external API with this window, such as Vulkan.
+        /// </para>
+        /// </remarks>
+        NoAPI,
+
+        /// <summary>
+        /// Indicates that the context should be created for OpenGL ES.
+        /// </summary>
+        OpenGLES,
+
+        /// <summary>
+        /// Indicates that the context should be created for OpenGL.
+        /// </summary>
+        OpenGL,
+
+        /// <summary>
+        /// Indicates that the context should be created for Vulkan.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// As of right now, this does the same thing as <see cref="NoAPI"/>
+        /// </para>
+        /// </remarks>
+        Vulkan,
+    }
+}

src/Windowing/OpenToolkit.Windowing.Common/Enums/ContextFlags.cs

@@ -0,0 +1,43 @@
+//
+// ContextFlags.cs
+//
+// Copyright (C) 2019 OpenTK
+//
+// This software may be modified and distributed under the terms
+// of the MIT license. See the LICENSE file for details.
+//
+
+using System;
+
+namespace OpenToolkit.Windowing.Common
+{
+    /// <summary>
+    /// Enumerates various flags that affect the creation of new GraphicsContexts.
+    /// </summary>
+    [Flags]
+    public enum ContextFlags
+    {
+        /// <summary>
+        /// The default value of the GraphicsContextFlags enumeration.
+        /// </summary>
+        Default = 0,
+
+        /// <summary>
+        /// Indicates that this is a debug GraphicsContext. Debug contexts may provide
+        /// additional debugging information at the cost of performance.
+        /// </summary>
+        Debug = 1,
+
+        /// <summary>
+        /// Indicates that this is a forward compatible GraphicsContext. Forward-compatible contexts
+        /// do not support functionality marked as deprecated in the current GraphicsContextVersion.
+        /// </summary>
+        /// <remarks>Forward-compatible contexts are defined only for OpenGL versions 3.0 and later.</remarks>
+        ForwardCompatible = 2,
+
+        /// <summary>
+        /// Indicates that this GraphicsContext is intended for offscreen rendering.
+        /// </summary>
+        Offscreen = 4,
+    }
+}

src/Windowing/OpenToolkit.Windowing.Common/Enums/ContextProfile.cs

@@ -0,0 +1,27 @@
+//
+// ContextProfile.cs
+//
+// Copyright (C) 2019 OpenTK
+//
+// This software may be modified and distributed under the terms
+// of the MIT license. See the LICENSE file for details.
+//
+
+namespace OpenToolkit.Windowing.Common
+{
+    /// <summary>
+    /// Selects the profile for the context's graphics API. This only applies on OpenGL 3.2 upwards, and has no effect on older versions.
+    /// </summary>
+    public enum ContextProfile
+    {
+        /// <summary>
+        /// Selects compatability profile. You should only use this if maintaining legacy code.
+        /// </summary>
+        Compatability,
+
+        /// <summary>
+        /// Selects core profile. All new projects should use this unless they have a good reason not to.
+        /// </summary>
+        Core,
+    }
+}

src/Windowing/OpenToolkit.Windowing.Common/Interfaces/INativeWindowProperties.cs

@@ -7,6 +7,7 @@
 // of the MIT license. See the LICENSE file for details.
 //
 
+using System;
 using OpenToolkit.Mathematics;
 using OpenToolkit.Windowing.Common.Input;
 
@@ -39,6 +40,26 @@ public interface INativeWindowProperties
         /// </summary>
         Monitor CurrentMonitor { get; set; }
 
+        /// <summary>
+        /// Gets a value representing the current graphics API.
+        /// </summary>
+        ContextAPI API { get; }
+
+        /// <summary>
+        /// Gets a value representing the current graphics API profile.
+        /// </summary>
+        ContextProfile Profile { get; }
+
+        /// <summary>
+        /// Gets a value representing the current graphics profile flags.
+        /// </summary>
+        ContextFlags Flags { get; }
+
+        /// <summary>
+        /// Gets a value representing the current version of the graphics API.
+        /// </summary>
+        Version APIVersion { get; }
+
         /// <summary>
         /// Gets or sets the clipboard string.
         /// </summary>

src/Windowing/OpenToolkit.Windowing.Common/OpenToolkit.Windowing.Common.csproj

@@ -21,10 +21,6 @@
     <ProjectReference Include="..\..\OpenToolkit.Mathematics\OpenToolkit.Mathematics.csproj" />
   </ItemGroup>
 
-  <ItemGroup>
-    <Folder Include="Enums" />
-  </ItemGroup>
-
   <Import Project="..\..\..\props\common.props" />
   <Import Project="..\..\..\props\nuget-common.props" />
   <Import Project="..\..\..\props\stylecop.props" />

src/Windowing/OpenToolkit.Windowing.Desktop/NativeWindow.cs

@@ -108,6 +108,18 @@ public string Title
             }
         }
 
+        /// <inheritdoc />
+        public ContextAPI API { get; }
+
+        /// <inheritdoc />
+        public ContextProfile Profile { get; }
+
+        /// <inheritdoc />
+        public ContextFlags Flags { get; }
+
+        /// <inheritdoc />
+        public Version APIVersion { get; }
+
         private Monitor _currentMonitor;
 
         /// <summary>
@@ -466,6 +478,43 @@ public NativeWindow(INativeWindowProperties settings)
                         break;
                 }
 
+                switch (API)
+                {
+                    case ContextAPI.Vulkan:
+                    case ContextAPI.NoAPI:
+                        Glfw.WindowHint(WindowHintClientApi.ClientApi, ClientApi.NoApi);
+                        break;
+
+                    case ContextAPI.OpenGLES:
+                        Glfw.WindowHint(WindowHintClientApi.ClientApi, ClientApi.OpenGlEsApi);
+                        break;
+
+                    case ContextAPI.OpenGL:
+                        Glfw.WindowHint(WindowHintClientApi.ClientApi, ClientApi.OpenGlApi);
+                        break;
+
+                    default:
+                        throw new ArgumentOutOfRangeException();
+                }
+
+                Glfw.WindowHint(WindowHintInt.ContextVersionMajor, APIVersion.Major);
+                Glfw.WindowHint(WindowHintInt.ContextVersionMinor, APIVersion.Minor);
+
+                if (Flags.HasFlag(ContextFlags.ForwardCompatible))
+                {
+                    Glfw.WindowHint(WindowHintBool.OpenGLForwardCompat, true);
+                }
+
+                if (Flags.HasFlag(ContextFlags.Debug))
+                {
+                    Glfw.WindowHint(WindowHintBool.OpenGLDebugContext, true);
+                }
+
+                Glfw.WindowHint
+                (
+                    WindowHintOpenGlProfile.OpenGlProfile, (OpenGlProfile)Profile
+                );
+
                 Glfw.WindowHint(WindowHintBool.Focused, settings.IsFocused);
                 _windowBorder = settings.WindowBorder;
 

src/Windowing/OpenToolkit.Windowing.Desktop/NativeWindowSettings.cs

@@ -52,6 +52,11 @@ public NativeWindowSettings()
             Width = 640;
             Height = 360;
 
+            API = ContextAPI.OpenGL;
+            Profile = ContextProfile.Core;
+            Flags = ContextFlags.Default;
+            APIVersion = new Version(3, 3);
+
             IsFullscreen = false;
 
             Exists = true;
@@ -66,6 +71,26 @@ public NativeWindowSettings()
         /// <inheritdoc />
         public string ClipboardString { get; set; }
 
+        /// <summary>
+        /// Gets or sets a value representing the current graphics API.
+        /// </summary>
+        public ContextAPI API { get; set; }
+
+        /// <summary>
+        /// Gets or sets a value representing the current graphics API profile.
+        /// </summary>
+        public ContextProfile Profile { get; set; }
+
+        /// <summary>
+        /// Gets or sets a value representing the current graphics profile flags.
+        /// </summary>
+        public ContextFlags Flags { get; set; }
+
+        /// <summary>
+        /// Gets or sets a value representing the current version of the graphics API.
+        /// </summary>
+        public Version APIVersion { get; set; }
+
         /// <inheritdoc />
         public Monitor CurrentMonitor { get; set; }