SKVertices: CreateCopy is missing overload to pass vertices' and indexes' offset + count

Author: seclerp

binding/Binding/SKVertices.cs

@@ -31,6 +31,19 @@ public static SKVertices CreateCopy (SKVertexMode vmode, SKPoint[] positions, SK
 		}
 
 		public static SKVertices CreateCopy (SKVertexMode vmode, SKPoint[] positions, SKPoint[] texs, SKColor[] colors, UInt16[] indices)
+		{
+			var vertexCount = positions.Length;
+			var indexCount = indices?.Length ?? 0;
+
+			return CreateCopy (vmode, vertexCount, positions, texs, colors, indexCount, indices);
+		}
+
+		public static SKVertices CreateCopy (SKVertexMode vmode, int vertexCount, SKPoint[] positions, SKPoint[] texs, SKColor[] colors, int indexCount, UInt16[] indices)
+		{
+			return CreateCopy (vmode, 0, vertexCount, positions, texs, colors, 0, indexCount, indices);
+		}
+
+		public static SKVertices CreateCopy (SKVertexMode vmode, int vertexOffset, int vertexCount, SKPoint[] positions, SKPoint[] texs, SKColor[] colors, int indexOffset, int indexCount, UInt16[] indices)
 		{
 			if (positions == null)
 				throw new ArgumentNullException (nameof (positions));
@@ -40,14 +53,23 @@ public static SKVertices CreateCopy (SKVertexMode vmode, SKPoint[] positions, SK
 			if (colors != null && positions.Length != colors.Length)
 				throw new ArgumentException ("The number of colors must match the number of vertices.", nameof (colors));
 
-			var vertexCount = positions.Length;
-			var indexCount = indices?.Length ?? 0;
+			if (vertexOffset >= positions.Length)
+				throw new ArgumentException ("The vertex offset should be in bounds of vertex array.", nameof (vertexOffset));
+
+			if (vertexOffset + vertexCount >= positions.Length)
+				throw new ArgumentException ("The vertex count should be in bounds of vertex array.", nameof (vertexOffset));
+
+			if (indexOffset >= indices.Length)
+				throw new ArgumentException ("The index offset should be in bounds of index array.", nameof (vertexOffset));
+
+			if (indexOffset + indexCount >= indices.Length)
+				throw new ArgumentException ("The vertex count should be in bounds of vertex array.", nameof (vertexOffset));
 
 			fixed (SKPoint* p = positions)
 			fixed (SKPoint* t = texs)
 			fixed (SKColor* c = colors)
 			fixed (UInt16* i = indices) {
-				return GetObject (SkiaApi.sk_vertices_make_copy (vmode, vertexCount, p, t, (uint*)c, indexCount, i));
+				return GetObject (SkiaApi.sk_vertices_make_copy (vmode, vertexCount, p + vertexOffset, t + vertexOffset, (uint*)c + vertexOffset, indexCount, i + indexOffset));
 			}
 		}