/// <summary>
/// Initializes a new instance of the <see cref="MeshReader"/> class.
/// </summary>
/// <param name="mesh">The mesh.</param>
/// <param name="definition">The mesh's definition data.</param>
public MeshReader(Mesh mesh, RenderGeometryResourceDefinition definition)
{
Mesh = mesh;
Definition = definition;
VertexStreams = new VertexBufferDefinition[StreamCount];
IndexBuffers = new IndexBufferDefinition[IndexBufferCount];
BindVertexStreams();
BindIndexBuffers();
}
/// <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 uint[] ReadIndexes(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 indexes
var indexStream = reader.OpenIndexBufferStream(indexBuffer, resourceStream);
indexStream.Position = part.FirstIndex;
switch (indexBuffer.Type)
{
case PrimitiveType.TriangleList:
return indexStream.ReadIndexes(part.IndexCount);
case PrimitiveType.TriangleStrip:
return indexStream.ReadTriangleStrip(part.IndexCount);
default:
throw new InvalidOperationException("Unsupported index buffer type: " + indexBuffer.Type);
}
}