Refactored the interop classes.

* Moved DotSDL.Sdl to DotSDL.Interop.Core to allow for external
      library (SDL_mixer, SDL_image, etc) support down the road and
      to make their purpose more clear.
    * Changed DllName constant to CoreLib to fit the namespace
      change.

DotSDL/Audio/FormatConverter.cs

@@ -1,5 +1,5 @@
 using System;
-using SdlAudio = DotSDL.Sdl.Audio;
+using SdlAudio = DotSDL.Interop.Core.Audio;
 
 namespace DotSDL.Audio {
     /// <summary>

DotSDL/Audio/Playback.cs

@@ -1,7 +1,7 @@
-using DotSDL.Sdl;
-using SdlAudio = DotSDL.Sdl.Audio;
+using SdlAudio = DotSDL.Interop.Core.Audio;
 using System;
 using System.Runtime.InteropServices;
+using DotSDL.Interop.Core;
 
 namespace DotSDL.Audio {
     /// <summary>

DotSDL/Events/EventConversion.cs

@@ -1,4 +1,4 @@
-using SdlEvents = DotSDL.Sdl.Events;
+using SdlEvents = DotSDL.Interop.Core.Events;
 
 namespace DotSDL.Events {
     /// <summary>

DotSDL/Events/EventHandler.cs

@@ -1,6 +1,6 @@
 using System;
 using System.Runtime.InteropServices;
-using SdlEvents = DotSDL.Sdl.Events;
+using SdlEvents = DotSDL.Interop.Core.Events;
 
 namespace DotSDL.Events {
     /// <summary>

DotSDL/Graphics/SdlWindow.cs

@@ -1,7 +1,7 @@
 using DotSDL.Events;
 using DotSDL.Input;
-using DotSDL.Sdl;
 using System;
+using DotSDL.Interop.Core;
 
 namespace DotSDL.Graphics {
     /// <summary>

DotSDL/Interop/Core/Audio.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Runtime.InteropServices;
 
-namespace DotSDL.Sdl {
+namespace DotSDL.Interop.Core {
     /// <summary>
     /// Contains the necessary constants and function imports from SDL_audio.h.
     /// </summary>
@@ -165,7 +165,7 @@ namespace DotSDL.Sdl {
         /// Shuts down audio processing and closes the audio device.
         /// </summary>
         /// <param name="dev">An audio device previously opened by <see cref="OpenAudioDevice"/>.</param>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_CloseAudioDevice", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_CloseAudioDevice", CallingConvention = CallingConvention.Cdecl)]
         internal static extern void CloseAudioDevice(uint dev);
 
         /// <summary>
@@ -186,7 +186,7 @@ namespace DotSDL.Sdl {
         /// <param name="allowedChanges"></param>
         /// <returns>A non-zero value on success or zero on failure. This will never
         /// return 1, since SDL reserves that ID for the SDL_OpenAudio() function.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_OpenAudioDevice", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_OpenAudioDevice", CallingConvention = CallingConvention.Cdecl)]
         internal static extern uint OpenAudioDevice(IntPtr device, int isCapture, ref AudioSpec desired, out AudioSpec obtained, AllowedChanges allowedChanges);
 
         /// <summary>
@@ -207,7 +207,7 @@ namespace DotSDL.Sdl {
         /// <param name="allowedChanges"></param>
         /// <returns>A non-zero value on success or zero on failure. This will never
         /// return 1, since SDL reserves that ID for the SDL_OpenAudio() function.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_OpenAudioDevice", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_OpenAudioDevice", CallingConvention = CallingConvention.Cdecl)]
         internal static extern uint OpenAudioDevice(string device, int isCapture, ref AudioSpec desired, out AudioSpec obtained, AllowedChanges allowedChanges);
 
         /// <summary>
@@ -215,7 +215,7 @@ namespace DotSDL.Sdl {
         /// </summary>
         /// <param name="dev">The audio device to change.</param>
         /// <param name="pauseOn">The <see cref="AudioState"/> to switch to.</param>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_PauseAudioDevice", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_PauseAudioDevice", CallingConvention = CallingConvention.Cdecl)]
         internal static extern void PauseAudioDevice(uint dev, AudioState pauseOn);
     }
 }

DotSDL/Interop/Core/Events.cs

@@ -1,14 +1,14 @@
-using ControllerButton = DotSDL.Input.Controller.Button;
+using System;
+using System.Runtime.InteropServices;
 using DotSDL.Events;
 using DotSDL.Input;
 using DotSDL.Input.Controller;
 using DotSDL.Input.Joystick;
 using DotSDL.Input.Mouse;
+using ControllerButton = DotSDL.Input.Controller.Button;
 using MouseButton = DotSDL.Input.Mouse.Button;
-using System;
-using System.Runtime.InteropServices;
 
-namespace DotSDL.Sdl {
+namespace DotSDL.Interop.Core {
     /// <summary>
     /// Contains the necessary constants and function imports from SDL_events.h.
     /// </summary>
@@ -485,7 +485,7 @@ namespace DotSDL.Sdl {
         /// </summary>
         /// <param name="sdlEvent">An object to store event data into. If this is not NULL, the event is removed from the queue and stored into the object.</param>
         /// <returns>1 if there are any pending events, or 0 if there are none available.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_PollEvent", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_PollEvent", CallingConvention = CallingConvention.Cdecl)]
         internal static extern int PollEvent(ref SdlEvent sdlEvent);
     }
 }

DotSDL/Interop/Core/Init.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Runtime.InteropServices;
 
-namespace DotSDL.Sdl {
+namespace DotSDL.Interop.Core {
     /// <summary>
     /// Contains the necessary constants and function imports from SDL.h.
     /// </summary>
@@ -44,7 +44,7 @@ namespace DotSDL.Sdl {
         /// </summary>
         /// <param name="flags">Flags indicating which subsystem or subsystems to initialize.</param>
         /// <returns>0 on success or a negative error code on failure.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_Init", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_Init", CallingConvention = CallingConvention.Cdecl)]
         internal static extern int Initialize(SubsystemFlags flags);
 
         /// <summary>
@@ -58,7 +58,7 @@ namespace DotSDL.Sdl {
         /// </summary>
         /// <param name="flags">Flags indicating which subsystem or subsystems to initialize.</param>
         /// <returns>0 on success or a negative error code on failure.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_InitSubSystem", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_InitSubSystem", CallingConvention = CallingConvention.Cdecl)]
         internal static extern int InitSubSystem(SubsystemFlags flags);
 
         /// <summary>
@@ -66,7 +66,7 @@ namespace DotSDL.Sdl {
         /// </summary>
         /// <param name="flags">Flags indicating which subsystem or subsystems to quit.</param>
         /// <returns>0 on success or a negative error code on failure.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_QuitSubSystem", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_QuitSubSystem", CallingConvention = CallingConvention.Cdecl)]
         internal static extern int QuitSubSystem(SubsystemFlags flags);
 
         /// <summary>
@@ -77,14 +77,14 @@ namespace DotSDL.Sdl {
         /// </summary>
         /// <param name="flags">Flags indicating which subsystem or subsystems to query.</param>
         /// <returns>A set of all initialized subsystems.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_WasInit", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_WasInit", CallingConvention = CallingConvention.Cdecl)]
         internal static extern SubsystemFlags WasInit(SubsystemFlags flags);
 
         /// <summary>
         /// This function cleans up all initialized subsystems. You should call it upon all
         /// exit conditions.
         /// </summary>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_Quit", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_Quit", CallingConvention = CallingConvention.Cdecl)]
         internal static extern void Quit();
     }
 }

DotSDL/Interop/Core/Keyboard.cs

@@ -1,6 +1,6 @@
 using DotSDL.Input.Keyboard;
 
-namespace DotSDL.Sdl {
+namespace DotSDL.Interop.Core {
     /// <summary>
     /// Contains the necessary constants and function imports from SDL_keyboard.h.
     /// </summary>

DotSDL/Interop/Core/Pixels.cs

@@ -1,6 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 
-namespace DotSDL.Sdl {
+namespace DotSDL.Interop.Core {
     /// <summary>
     /// Contains the necessary constants and function imports from SDL_pixels.h.
     /// </summary>

DotSDL/Interop/Core/Power.cs

@@ -1,7 +1,7 @@
-using DotSDL.Power;
-using System.Runtime.InteropServices;
+using System.Runtime.InteropServices;
+using DotSDL.Power;
 
-namespace DotSDL.Sdl {
+namespace DotSDL.Interop.Core {
     /// <summary>
     /// Contains the necessary constants and function imports from SDL_power.h.
     /// </summary>
@@ -16,7 +16,7 @@ namespace DotSDL.Sdl {
         /// You can pass a NULL here if you don't care. Will return -1 if we
         /// can't determine a value, or we're not running on a battery.</param>
         /// <returns>The state of the battery (if any).</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_GetPowerInfo", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_GetPowerInfo", CallingConvention = CallingConvention.Cdecl)]
         internal static extern BatteryStatus GetPowerInfo(out int secs, out int pct);
     }
 }

DotSDL/Interop/Core/Rect.cs

@@ -1,6 +1,6 @@
 using System.Runtime.InteropServices;
 
-namespace DotSDL.Sdl {
+namespace DotSDL.Interop.Core {
     /// <summary>
     /// Contains the necessary constants and function imports from SDL_rect.h.
     /// </summary>

DotSDL/Interop/Core/Render.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Runtime.InteropServices;
 
-namespace DotSDL.Sdl {
+namespace DotSDL.Interop.Core {
     /// <summary>
     /// Contains the necessary constants and function imports from SDL_render.h.
     /// </summary>
@@ -46,7 +46,7 @@ namespace DotSDL.Sdl {
         /// to initialize the first one supporting the requested flags.</param>
         /// <param name="flags">The requested flags for the renderer.</param>
         /// <returns>A valid rendering context or NULL if there was an error.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_CreateRenderer", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_CreateRenderer", CallingConvention = CallingConvention.Cdecl)]
         internal static extern IntPtr CreateRenderer(IntPtr window, int index, RendererFlags flags);
 
         /// <summary>
@@ -59,7 +59,7 @@ namespace DotSDL.Sdl {
         /// <param name="h">The height of the texture in pixels.</param>
         /// <returns>The created texture is returned, or NULL if no rendering context was
         /// active, the foramt was unsupported, or the width or height were out of range.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_CreateTexture", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_CreateTexture", CallingConvention = CallingConvention.Cdecl)]
         internal static extern IntPtr CreateTexture(IntPtr renderer, uint format, TextureAccess access, int w, int h);
 
         /// <summary>
@@ -69,7 +69,7 @@ namespace DotSDL.Sdl {
         /// </summary>
         /// <param name="renderer">The renderer to clear.</param>
         /// <returns>0 on success, -1 on error.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_RenderClear", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_RenderClear", CallingConvention = CallingConvention.Cdecl)]
         internal static extern int RenderClear(IntPtr renderer);
 
         /// <summary>
@@ -80,16 +80,16 @@ namespace DotSDL.Sdl {
         /// <param name="srcRect">The source rectangle, or NULL for the entire texture.</param>
         /// <param name="dstRect">The destination rectangle, or NULL For the entire rendering target.</param>
         /// <returns>0 on success, or -1 on error.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_RenderCopy", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_RenderCopy", CallingConvention = CallingConvention.Cdecl)]
         internal static extern int RenderCopy(IntPtr renderer, IntPtr texture, Rect.SdlRect srcRect, Rect.SdlRect dstRect);
-        [DllImport(Meta.DllName, EntryPoint = "SDL_RenderCopy", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_RenderCopy", CallingConvention = CallingConvention.Cdecl)]
         internal static extern int RenderCopy(IntPtr renderer, IntPtr texture, IntPtr srcRect, IntPtr dstRect);
 
         /// <summary>
         /// Update the screen with the rendering performed.
         /// </summary>
         /// <param name="renderer">The renderer to update.</param>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_RenderPresent", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_RenderPresent", CallingConvention = CallingConvention.Cdecl)]
         internal static extern void RenderPresent(IntPtr renderer);
 
         /// <summary>
@@ -100,7 +100,7 @@ namespace DotSDL.Sdl {
         /// <param name="pixels">The raw pixel data.</param>
         /// <param name="pitch">The number of bytes in a row of pixel data, including padding between lines.</param>
         /// <returns>0 on success, or -1 if the texture is not valid.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_UpdateTexture", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_UpdateTexture", CallingConvention = CallingConvention.Cdecl)]
         internal static extern int UpdateTexture(IntPtr texture, IntPtr rect, IntPtr pixels, int pitch);
 
         /// <summary>
@@ -111,7 +111,7 @@ namespace DotSDL.Sdl {
         /// <param name="pixels">The raw pixel data.</param>
         /// <param name="pitch">The number of bytes in a row of pixel data, including padding between lines.</param>
         /// <returns>0 on success, or -1 if the texture is not valid.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_UpdateTexture", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_UpdateTexture", CallingConvention = CallingConvention.Cdecl)]
         internal static extern int UpdateTexture(IntPtr texture, Rect.SdlRect rect, IntPtr pixels, int pitch);
     }
 }

DotSDL/Interop/Core/Timer.cs

@@ -1,6 +1,6 @@
 using System.Runtime.InteropServices;
 
-namespace DotSDL.Sdl {
+namespace DotSDL.Interop.Core {
     /// <summary>
     /// Contains the necessary constants and function imports from SDL_timer.h.
     /// </summary>
@@ -9,14 +9,14 @@ namespace DotSDL.Sdl {
         /// Wait a specified number of milliseconds before returning.
         /// </summary>
         /// <param name="ms">The number of milliseconds to wait.</param>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_Delay", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_Delay", CallingConvention = CallingConvention.Cdecl)]
         internal static extern void Delay(uint ms);
 
         /// <summary>
         /// Retrieves the number of milliseconds since the SDL library was initialized.
         /// </summary>
         /// <returns>The number of milliseconds since the SDL library was initialized.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_GetTicks", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_GetTicks", CallingConvention = CallingConvention.Cdecl)]
         internal static extern uint GetTicks();
     }
 }

DotSDL/Interop/Core/Video.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Runtime.InteropServices;
 
-namespace DotSDL.Sdl {
+namespace DotSDL.Interop.Core {
     /// <summary>
     /// Contains the necessary constants and function imports from SDL_video.h.
     /// </summary>
@@ -85,14 +85,14 @@ namespace DotSDL.Sdl {
         /// <param name="h">The height of the window, in screen coordinates.</param>
         /// <param name="flags">One or more <see cref="WindowFlags"/> OR'd together.</param>
         /// <returns>The window that was created, or NULL on failure.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_CreateWindow", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_CreateWindow", CallingConvention = CallingConvention.Cdecl)]
         internal static extern IntPtr CreateWindow(string title, int x, int y, int w, int h, WindowFlags flags);
 
         /// <summary>
         /// Destroys an SDL window.
         /// </summary>
         /// <param name="window">The window to destroy.</param>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_DestroyWindow", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_DestroyWindow", CallingConvention = CallingConvention.Cdecl)]
         internal static extern void DestroyWindow(IntPtr window);
 
         /// <summary>
@@ -100,14 +100,14 @@ namespace DotSDL.Sdl {
         /// </summary>
         /// <param name="window">The window to query.</param>
         /// <returns>The ID of the window.</returns>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_GetWindowID", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_GetWindowID", CallingConvention = CallingConvention.Cdecl)]
         internal static extern uint GetWindowId(IntPtr window);
 
         /// <summary>
         /// Shows an SDL window.
         /// </summary>
         /// <param name="window">The window to show.</param>
-        [DllImport(Meta.DllName, EntryPoint = "SDL_ShowWindow", CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(Meta.CoreLib, EntryPoint = "SDL_ShowWindow", CallingConvention = CallingConvention.Cdecl)]
         internal static extern void ShowWindow(IntPtr window);
     }
 }

DotSDL/Interop/Meta.cs

@@ -1,4 +1,4 @@
-namespace DotSDL.Sdl {
+namespace DotSDL.Interop {
     /// <summary>
     /// Contains .NET constants to assist with making calls to the SDL library.
     /// </summary>
@@ -6,6 +6,6 @@
         /// <summary>
         /// Contains the name of the SDL library.
         /// </summary>
-        internal const string DllName = "SDL2";
+        internal const string CoreLib = "SDL2";
     }
 }

DotSDL/Power/PowerState.cs

@@ -13,7 +13,7 @@ namespace DotSDL.Power {
         /// </summary>
         public static PowerStatus CurrentPowerState {
             get {
-                var state = Sdl.Power.GetPowerInfo(out var secs, out var pct);
+                var state = Interop.Core.Power.GetPowerInfo(out var secs, out var pct);
                 return new PowerStatus {
                     BatteryStatus = state,
                     BatteryPercent = pct,

DotSDL/SdlInit.cs

@@ -1,6 +1,6 @@
-using DotSDL.Sdl;
-using System;
+using System;
 using System.Collections.Generic;
+using DotSDL.Interop.Core;
 
 namespace DotSDL {
     /// <summary>