/// <summary>
/// Called just prior to rendering the component.
/// </summary>
protected override void OnRender()
{
if (m_vertexBuffer == null)
{
m_vertexBuffer = new VertexBuffer <VertexPNC>(24);
m_surface.SetVertexBuffer(m_vertexBuffer, PrimitiveType.Lines);
}
if (m_dirty)
{
ReadOnlyCollection <Vector3> corners = m_mesh.Bounds.Corners;
// clear any lines
m_vertexBuffer.Clear();
// get the underlying buffer
int offset;
VertexPNC[] verts = m_vertexBuffer.WriteDirectly(24, out offset);
// each consecutive pair of elements forms a line segment drawn to form the box wireframe
verts[0] = new VertexPNC(corners[0], Vector3.Zero, Color4.White);
verts[1] = new VertexPNC(corners[4], Vector3.Zero, Color4.White);
verts[2] = new VertexPNC(corners[1], Vector3.Zero, Color4.White);
verts[3] = new VertexPNC(corners[5], Vector3.Zero, Color4.White);
verts[4] = new VertexPNC(corners[2], Vector3.Zero, Color4.White);
verts[5] = new VertexPNC(corners[6], Vector3.Zero, Color4.White);
verts[6] = new VertexPNC(corners[3], Vector3.Zero, Color4.White);
verts[7] = new VertexPNC(corners[7], Vector3.Zero, Color4.White);
verts[8] = new VertexPNC(corners[0], Vector3.Zero, Color4.White);
verts[9] = new VertexPNC(corners[1], Vector3.Zero, Color4.White);
verts[10] = new VertexPNC(corners[1], Vector3.Zero, Color4.White);
verts[11] = new VertexPNC(corners[3], Vector3.Zero, Color4.White);
verts[12] = new VertexPNC(corners[3], Vector3.Zero, Color4.White);
verts[13] = new VertexPNC(corners[2], Vector3.Zero, Color4.White);
verts[14] = new VertexPNC(corners[2], Vector3.Zero, Color4.White);
verts[15] = new VertexPNC(corners[0], Vector3.Zero, Color4.White);
verts[16] = new VertexPNC(corners[4], Vector3.Zero, Color4.White);
verts[17] = new VertexPNC(corners[5], Vector3.Zero, Color4.White);
verts[18] = new VertexPNC(corners[5], Vector3.Zero, Color4.White);
verts[19] = new VertexPNC(corners[7], Vector3.Zero, Color4.White);
verts[20] = new VertexPNC(corners[7], Vector3.Zero, Color4.White);
verts[21] = new VertexPNC(corners[6], Vector3.Zero, Color4.White);
verts[22] = new VertexPNC(corners[6], Vector3.Zero, Color4.White);
verts[23] = new VertexPNC(corners[4], Vector3.Zero, Color4.White);
// upload the lines to the GPU if changed
m_vertexBuffer.BufferData();
}
}
