Added ugc addtional previews

Facepunch.Steamworks/Structs/UgcAdditionalPreview.cs

@@ -0,0 +1,33 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Steamworks.Data
+{
+	public struct UgcAdditionalPreview
+	{
+		internal UgcAdditionalPreview( string urlOrVideoID, string originalFileName, ItemPreviewType itemPreviewType )
+		{
+			this.UrlOrVideoID = urlOrVideoID;
+			this.OriginalFileName = originalFileName;
+			this.ItemPreviewType = itemPreviewType;
+		}
+
+		public string UrlOrVideoID { get; private set; }
+		public string OriginalFileName { get; private set; }
+		internal ItemPreviewType ItemPreviewType { get; private set; }
+
+		/// <summary>
+		/// Flags that specify the type of preview an item has:
+		/// Image = 0,
+		/// YouTubeVideo = 1,
+		/// Sketchfab = 2,
+		/// EnvironmentMap_HorizontalCross = 3,
+		/// EnvironmentMap_LatLong = 4,
+		/// ReservedMax = 255
+		/// </summary>
+		public int GetItemPreviewType() => (int)ItemPreviewType;
+	}
+}

Facepunch.Steamworks/Structs/UgcAdditionalPreview.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 48f086235d5dbeb44bccbb40802e30fb
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Facepunch.Steamworks/Structs/UgcItem.cs

@@ -113,6 +113,11 @@ public Item( PublishedFileId id ) : this()
 		/// </summary>
 		public PublishedFileId[] Children;
 
+		/// <summary>
+		/// Additional previews of this item or collection, available only from WithAdditionalPreviews(true) queries
+		/// </summary>
+		public UgcAdditionalPreview[] AdditionalPreviews { get; internal set; }
+
         public bool IsInstalled => (State & ItemState.Installed) == ItemState.Installed;
 		public bool IsDownloading => (State & ItemState.Downloading) == ItemState.Downloading;
 		public bool IsDownloadPending => (State & ItemState.DownloadPending) == ItemState.DownloadPending;

Facepunch.Steamworks/Structs/UgcQuery.cs

@@ -153,6 +153,7 @@ public Query WithFileId( params PublishedFileId[] files )
 				ReturnsDefaultStats = WantsDefaultStats ?? true, //true by default
 				ReturnsMetadata = WantsReturnMetadata ?? false,
 				ReturnsChildren = WantsReturnChildren ?? false,
+				ReturnsAdditionalPreviews = WantsReturnAdditionalPreviews ?? false,
 			};
 		}
 

Facepunch.Steamworks/Structs/UgcResultPage.cs

@@ -16,6 +16,7 @@ public struct ResultPage : System.IDisposable
 		internal bool ReturnsDefaultStats;
 		internal bool ReturnsMetadata;
 		internal bool ReturnsChildren;
+		internal bool ReturnsAdditionalPreviews;
 
 		public IEnumerable<Item> Entries
 		{
@@ -83,7 +84,27 @@ public IEnumerable<Item> Entries
 								item.Children = children;
 							}
 						}
-						// TODO GetQueryUGCAdditionalPreview
+
+						if ( ReturnsAdditionalPreviews )
+						{
+							var previewsCount = SteamUGC.Internal.GetQueryUGCNumAdditionalPreviews( Handle, i );
+							if ( previewsCount > 0 )
+							{
+								item.AdditionalPreviews = new UgcAdditionalPreview[previewsCount];
+								for ( uint j = 0; j < previewsCount; j++ )
+								{
+									string previewUrlOrVideo;
+									string originalFileName; //what is this???
+									ItemPreviewType previewType = default;
+									if ( SteamUGC.Internal.GetQueryUGCAdditionalPreview(
+										Handle, i, j, out previewUrlOrVideo, out originalFileName, ref previewType ) )
+									{
+										item.AdditionalPreviews[j] = new UgcAdditionalPreview( 
+											previewUrlOrVideo, originalFileName, previewType );
+									}
+								}
+							}
+						}
 
 						yield return item;
 					}