public void Draw(Skeleton skeleton)
        {
            float[] vertices = this.vertices;
            var     drawOrder = skeleton.DrawOrder;
            var     drawOrderItems = skeleton.DrawOrder.Items;
            float   skeletonR = skeleton.R, skeletonG = skeleton.G, skeletonB = skeleton.B, skeletonA = skeleton.A;

            for (int i = 0, n = drawOrder.Count; i < n; i++)
            {
                Slot       slot       = drawOrderItems[i];
                Attachment attachment = slot.Attachment;
                if (attachment is RegionAttachment)
                {
                    RegionAttachment regionAttachment = (RegionAttachment)attachment;
                    BlendState       blend            = slot.Data.BlendMode == BlendMode.additive ? BlendState.Additive : defaultBlendState;
                    if (device.BlendState != blend)
                    {
                        End();
                        device.BlendState = blend;
                    }

                    MeshItem item = batcher.NextItem(4, 6);
                    item.triangles = quadTriangles;
                    VertexPositionColorTexture[] itemVertices = item.vertices;

                    AtlasRegion region = (AtlasRegion)regionAttachment.RendererObject;
                    item.texture = (Texture2D)region.page.rendererObject;

                    Color color;
                    float a = skeletonA * slot.A * regionAttachment.A;
                    if (premultipliedAlpha)
                    {
                        color = new Color(
                            skeletonR * slot.R * regionAttachment.R * a,
                            skeletonG * slot.G * regionAttachment.G * a,
                            skeletonB * slot.B * regionAttachment.B * a, a);
                    }
                    else
                    {
                        color = new Color(
                            skeletonR * slot.R * regionAttachment.R,
                            skeletonG * slot.G * regionAttachment.G,
                            skeletonB * slot.B * regionAttachment.B, a);
                    }
                    itemVertices[TL].Color = color;
                    itemVertices[BL].Color = color;
                    itemVertices[BR].Color = color;
                    itemVertices[TR].Color = color;

                    regionAttachment.ComputeWorldVertices(slot.Bone, vertices);
                    itemVertices[TL].Position.X = vertices[RegionAttachment.X1];
                    itemVertices[TL].Position.Y = vertices[RegionAttachment.Y1];
                    itemVertices[TL].Position.Z = 0;
                    itemVertices[BL].Position.X = vertices[RegionAttachment.X2];
                    itemVertices[BL].Position.Y = vertices[RegionAttachment.Y2];
                    itemVertices[BL].Position.Z = 0;
                    itemVertices[BR].Position.X = vertices[RegionAttachment.X3];
                    itemVertices[BR].Position.Y = vertices[RegionAttachment.Y3];
                    itemVertices[BR].Position.Z = 0;
                    itemVertices[TR].Position.X = vertices[RegionAttachment.X4];
                    itemVertices[TR].Position.Y = vertices[RegionAttachment.Y4];
                    itemVertices[TR].Position.Z = 0;

                    float[] uvs = regionAttachment.UVs;
                    itemVertices[TL].TextureCoordinate.X = uvs[RegionAttachment.X1];
                    itemVertices[TL].TextureCoordinate.Y = uvs[RegionAttachment.Y1];
                    itemVertices[BL].TextureCoordinate.X = uvs[RegionAttachment.X2];
                    itemVertices[BL].TextureCoordinate.Y = uvs[RegionAttachment.Y2];
                    itemVertices[BR].TextureCoordinate.X = uvs[RegionAttachment.X3];
                    itemVertices[BR].TextureCoordinate.Y = uvs[RegionAttachment.Y3];
                    itemVertices[TR].TextureCoordinate.X = uvs[RegionAttachment.X4];
                    itemVertices[TR].TextureCoordinate.Y = uvs[RegionAttachment.Y4];
                }
                else if (attachment is MeshAttachment)
                {
                    MeshAttachment mesh        = (MeshAttachment)attachment;
                    int            vertexCount = mesh.Vertices.Length;
                    if (vertices.Length < vertexCount)
                    {
                        vertices = new float[vertexCount];
                    }
                    mesh.ComputeWorldVertices(slot, vertices);

                    int[]    triangles = mesh.Triangles;
                    MeshItem item      = batcher.NextItem(vertexCount, triangles.Length);
                    item.triangles = triangles;

                    AtlasRegion region = (AtlasRegion)mesh.RendererObject;
                    item.texture = (Texture2D)region.page.rendererObject;

                    Color color;
                    float a = skeletonA * slot.A * mesh.A;
                    if (premultipliedAlpha)
                    {
                        color = new Color(
                            skeletonR * slot.R * mesh.R * a,
                            skeletonG * slot.G * mesh.G * a,
                            skeletonB * slot.B * mesh.B * a, a);
                    }
                    else
                    {
                        color = new Color(
                            skeletonR * slot.R * mesh.R,
                            skeletonG * slot.G * mesh.G,
                            skeletonB * slot.B * mesh.B, a);
                    }

                    float[] uvs = mesh.UVs;
                    VertexPositionColorTexture[] itemVertices = item.vertices;
                    for (int ii = 0, v = 0; v < vertexCount; ii++, v += 2)
                    {
                        itemVertices[ii].Color               = color;
                        itemVertices[ii].Position.X          = vertices[v];
                        itemVertices[ii].Position.Y          = vertices[v + 1];
                        itemVertices[ii].Position.Z          = 0;
                        itemVertices[ii].TextureCoordinate.X = uvs[v];
                        itemVertices[ii].TextureCoordinate.Y = uvs[v + 1];
                    }
                }
                else if (attachment is WeightedMeshAttachment)
                {
                    WeightedMeshAttachment mesh = (WeightedMeshAttachment)attachment;
                    int vertexCount             = mesh.UVs.Length;
                    if (vertices.Length < vertexCount)
                    {
                        vertices = new float[vertexCount];
                    }
                    mesh.ComputeWorldVertices(slot, vertices);

                    int[]    triangles = mesh.Triangles;
                    MeshItem item      = batcher.NextItem(vertexCount, triangles.Length);
                    item.triangles = triangles;

                    AtlasRegion region = (AtlasRegion)mesh.RendererObject;
                    item.texture = (Texture2D)region.page.rendererObject;

                    Color color;
                    float a = skeletonA * slot.A * mesh.A;
                    if (premultipliedAlpha)
                    {
                        color = new Color(
                            skeletonR * slot.R * mesh.R * a,
                            skeletonG * slot.G * mesh.G * a,
                            skeletonB * slot.B * mesh.B * a, a);
                    }
                    else
                    {
                        color = new Color(
                            skeletonR * slot.R * mesh.R,
                            skeletonG * slot.G * mesh.G,
                            skeletonB * slot.B * mesh.B, a);
                    }

                    float[] uvs = mesh.UVs;
                    VertexPositionColorTexture[] itemVertices = item.vertices;
                    for (int ii = 0, v = 0; v < vertexCount; ii++, v += 2)
                    {
                        itemVertices[ii].Color               = color;
                        itemVertices[ii].Position.X          = vertices[v];
                        itemVertices[ii].Position.Y          = vertices[v + 1];
                        itemVertices[ii].Position.Z          = 0;
                        itemVertices[ii].TextureCoordinate.X = uvs[v];
                        itemVertices[ii].TextureCoordinate.Y = uvs[v + 1];
                    }
                }
            }
        }