Added some public RWops entry points.

src/SDL2.cs

@@ -64,7 +64,7 @@ namespace SDL2
 
 		#region SDL_rwops.h
 
-		/* Note about SDL2# and RWops:
+		/* Note about SDL2# and Internal RWops:
 		 * These functions are currently not supported for public use.
 		 * They are only meant to be used internally in functions marked with
 		 * the phrase "THIS IS AN RWops FUNCTION!"
@@ -84,6 +84,14 @@ namespace SDL2
 				string mode
 		);
 
+		/* These are the public RWops functions. They should be used by
+		 * functions marked with the phrase "THIS IS A PUBLIC RWops FUNCTION!"
+		 */
+
+		/* IntPtr refers to an SDL_RWops */
+		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
+		public static extern IntPtr SDL_RWFromMem(byte[] mem, int size);
+
 		#endregion
 
 		#region SDL_main.h

src/SDL2_image.cs

@@ -94,6 +94,14 @@ namespace SDL2
 				string file
 		);
 
+		/* src refers to an SDL_RWops*, IntPtr to an SDL_Surface* */
+		/* THIS IS A PUBLIC RWops FUNCTION! */
+		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
+		public static extern IntPtr IMG_Load_RW(
+			IntPtr src,
+			int freesrc
+		);
+
 		/* IntPtr refers to an SDL_Texture*, renderer to an SDL_Renderer* */
 		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
 		public static extern IntPtr IMG_LoadTexture(
@@ -120,6 +128,15 @@ namespace SDL2
 				string file
 		);
 
+		/* surface refers to an SDL_Surface*, dst to an SDL_RWops* */
+		/* THIS IS A PUBLIC RWops FUNCTION! */
+		[DllImport(nativeLibName, CallingConvention = CallingConvention.Cdecl)]
+		public static extern int IMG_SavePNG_RW(
+			IntPtr surface,
+			IntPtr dst,
+			int freedst
+		);
+
 		#endregion
 	}
 }