/// <summary>
/// Merges two glb files together
/// </summary>
/// <param name="mergeTo">The glb to update</param>
/// <param name="mergeFrom">The glb to merge from</param>
public static void MergeGLBs(GLBObject mergeTo, GLBObject mergeFrom)
{
if (mergeTo == null)
{
throw new ArgumentNullException(nameof(mergeTo));
}
if (mergeFrom == null)
{
throw new ArgumentNullException(nameof(mergeFrom));
}
// 1) merge json
// 2) copy mergefrom binary data to mergeto binary data
// 3) Fix up bufferviews to be the new offset
int previousBufferViewsCount = mergeTo.Root.BufferViews?.Count ?? 0;
uint previousBufferSize = mergeTo.BinaryChunkInfo.Length;
GLTFHelpers.MergeGLTF(mergeTo.Root, mergeFrom.Root);
_AddBinaryData(mergeTo, mergeFrom.Stream, false, mergeFrom.BinaryChunkInfo.StartPosition + GLTFParser.CHUNK_HEADER_SIZE);
uint bufferSizeDiff =
mergeTo.BinaryChunkInfo.Length -
previousBufferSize; // calculate buffer size change to update the byte offsets of the appended buffer views
if (mergeTo.Root.BufferViews != null)
{
for (int i = previousBufferViewsCount; i < mergeTo.Root.BufferViews.Count; ++i)
{
mergeTo.Root.BufferViews[i].ByteOffset += bufferSizeDiff;
}
}
}
/// <summary>
/// Turns a stream that contains glTF or a GLB data into a GLBObject. glTF is not yet supported
/// </summary>
/// <param name="inStream">The stream to turn into a GLB</param>
/// <param name="glbOutStream">If specified, output stream to write the GLB to</param>
/// <param name="loader">Loader for loading external components from GLTFRoot. Loader is required if loading from glTF</param>
/// <returns>A constructed GLBObject</returns>
public static GLBObject ConstructFromStream(Stream inStream, Stream glbOutStream = null, Func <string, Stream> loader = null,
long streamStartPosition = 0, bool removeUndefinedReferences = true)
{
if (inStream == null)
{
throw new ArgumentNullException(nameof(inStream));
}
if (inStream.Length > 0)
{
inStream.Position = streamStartPosition;
GLTFRoot root;
GLTFParser.ParseJson2020(inStream, out root, streamStartPosition);
if (removeUndefinedReferences)
{
GLTFHelpers.RemoveUndefinedReferences(root);
}
if (!root.IsGLB)
{
return(ConstructFromGLTF(root, glbOutStream, loader));
}
return(ConstructFromGLB(root, inStream, glbOutStream, streamStartPosition));
}
return(_ConstructFromEmptyStream(inStream, streamStartPosition));
}
