Add ByteEXT and UShortEXT

src/Graphics/SurfaceFormat.cs

@@ -116,5 +116,13 @@ public enum SurfaceFormat
 		/// BC7 block texture format where the R/G/B values are non-linear sRGB.
 		/// </summary>
 		Bc7SrgbEXT,
+		/// <summary>
+		/// Unsigned 8-bit R pixel format.
+		/// </summary>
+		ByteEXT,
+		/// <summary>
+		/// Unsigned 16-bit R pixel format.
+		/// </summary>
+		UShortEXT,
 	}
 }

src/Graphics/Texture.cs

@@ -130,6 +130,8 @@ public static int GetBlockSizeSquaredEXT(SurfaceFormat format)
 				case SurfaceFormat.Vector2:
 				case SurfaceFormat.HdrBlendable:
 				case SurfaceFormat.Vector4:
+				case SurfaceFormat.ByteEXT:
+				case SurfaceFormat.UShortEXT:
 					return 1;
 				default:
 					throw new ArgumentException("Should be a value defined in SurfaceFormat", "Format");
@@ -149,12 +151,14 @@ public static int GetFormatSizeEXT(SurfaceFormat format)
 				case SurfaceFormat.Bc7SrgbEXT:
 					return 16;
 				case SurfaceFormat.Alpha8:
+				case SurfaceFormat.ByteEXT:
 					return 1;
 				case SurfaceFormat.Bgr565:
 				case SurfaceFormat.Bgra4444:
 				case SurfaceFormat.Bgra5551:
 				case SurfaceFormat.HalfSingle:
 				case SurfaceFormat.NormalizedByte2:
+				case SurfaceFormat.UShortEXT:
 					return 2;
 				case SurfaceFormat.Color:
 				case SurfaceFormat.Single:

src/Graphics/Texture2D.cs

@@ -98,7 +98,9 @@ SurfaceFormat format
 						format != SurfaceFormat.HalfSingle &&
 						format != SurfaceFormat.HalfVector2 &&
 						format != SurfaceFormat.HalfVector4 &&
-						format != SurfaceFormat.HdrBlendable	)
+						format != SurfaceFormat.HdrBlendable &&
+						format != SurfaceFormat.ByteEXT &&
+						format != SurfaceFormat.UShortEXT)
 				{
 					// Not a renderable format period
 					Format = SurfaceFormat.Color;