/// <summary>
/// Buffers a part of the client data
/// </summary>
/// <param name="index">Starting element in the vertex definition</param>
/// <param name="count">Number of elements from the vertex definition to buffer</param>
/// <remarks>This function cannot be called once the client data has been freed</remarks>
public void BufferSubData(int index, int count)
{
int offset = 0;
int size = 0;
if (internal_array == null || internal_array.Length == 0)
{
throw new InvalidOperationException("Cannot buffer data from empty client array");
}
for (int i = 0; i < index; i++)
{
offset += VertexBufferDescriptor.GetElementSize(desc.types[i]);
}
for (int i = index; i < index + count; i++)
{
size += VertexBufferDescriptor.GetElementSize(desc.types[i]);
}
var ptr = System.Runtime.InteropServices.GCHandle.Alloc(internal_array, System.Runtime.InteropServices.GCHandleType.Pinned);
OpenGL.glBufferSubData(target, new IntPtr(offset), new IntPtr(size), ptr.AddrOfPinnedObject());
ptr.Free();
}
