/// <summary>
/// Reads the index buffer data and converts it into a triangle list if necessary.
/// </summary>
/// <param name="reader">The mesh reader to use.</param>
/// <param name="part">The mesh part to read.</param>
/// <param name="resourceStream">A stream open on the resource data.</param>
/// <returns>The index buffer converted into a triangle list.</returns>
private static ushort[] ReadIndices(MeshReader reader, Mesh.Part part, Stream resourceStream)
{
// Use index buffer 0
var indexBuffer = reader.IndexBuffers[0];
if (indexBuffer == null)
{
throw new InvalidOperationException("Index buffer 0 is null");
}
// Read the indices
var indexStream = reader.OpenIndexBufferStream(indexBuffer, resourceStream);
indexStream.Position = part.FirstIndexOld;
switch (indexBuffer.Format)
{
case IndexBufferFormat.TriangleList:
return(indexStream.ReadIndices(part.IndexCountOld));
case IndexBufferFormat.TriangleStrip:
return(indexStream.ReadTriangleStrip(part.IndexCountOld));
default:
throw new InvalidOperationException("Unsupported index buffer type: " + indexBuffer.Format);
}
}
/// <summary>
/// Begins a new part in the current mesh.
/// </summary>
/// <param name="materialIndex">Index of the material.</param>
/// <param name="firstIndex">The first index.</param>
/// <param name="indexCount">The index count.</param>
/// <param name="vertexCount">The vertex count.</param>
/// <exception cref="System.InvalidOperationException">Cannot define a part if no mesh is active</exception>
public void BeginPart(short materialIndex, ushort firstIndex, ushort indexCount, ushort vertexCount)
{
if (_currentMesh == null)
{
throw new InvalidOperationException("Cannot define a part if no mesh is active");
}
_currentPart = new Mesh.Part
{
MaterialIndex = materialIndex,
TransparentSortingIndex = -1,
FirstIndexOld = firstIndex,
IndexCountOld = indexCount,
FirstSubPartIndex = (short)(_currentMesh.Mesh.SubParts.Count - 1),
SubPartCount = 0,
// TODO: Unknown values here
VertexCount = vertexCount,
};
}
public void EndPart()
{
if (_currentPart == null)
{
throw new InvalidOperationException("Cannot end a part if no part is active");
}
if (_currentMesh == null)
{
throw new InvalidOperationException("Cannot end a part if no mesh is active");
}
if (_currentPermutation == null)
{
throw new InvalidOperationException("Cannot end a part if no permutation is active");
}
_currentPart.SubPartCount = (short)_subparts.Count;
_currentMesh.Mesh.SubParts.AddRange(_subparts);
_currentMesh.Mesh.Parts.Add(_currentPart);
_subparts.Clear();
_currentPart = null;
}
