/// <summary>
/// Updates the vertex buffer object from the <see cref="Vertices"/> array.
/// </summary>
/// <typeparam name="TVertex">The type of vertex buffer to use.</typeparam>
/// <param name="transform">Function that transforms the vertex array data to a interleaved struct format.</param>
private void UpdateVertices <TVertex>(
Func <Vector3, Vector3, Color4, TVertex> transform
) where TVertex : struct, IVertexData
{
// if the type of the vertex data has changed we need to create a new buffer
if (m_vertexBuffer != null && m_vertexBuffer.GetType() != typeof(VertexBuffer <TVertex>))
{
m_vertexBuffer.Dispose();
m_vertexBuffer = null;
}
// create vertex buffer if needed
if (m_vertexBuffer == null)
{
m_vertexBuffer = new VertexBuffer <TVertex>(m_vertices.Length);
}
// copy the vertices into the buffer
VertexBuffer <TVertex> buffer = m_vertexBuffer as VertexBuffer <TVertex>;
buffer.Clear();
int offset;
TVertex[] vertexArray = buffer.WriteDirectly(m_vertices.Length, out offset);
for (int i = 0; i < m_vertices.Length; i++)
{
vertexArray[i] = transform(m_vertices[i], m_normals[i], m_colors[i]);
}
// upload to the GPU
buffer.BufferData();
m_vertexBufferDirty = false;
}