public void CreateBillboardVertices()
{
if (_items==null || !_items.Any())
return;
var billboardVertices = new StaticBillboardVertex[_items.Count * 6];
var i = 0;
var random = new Random();
foreach (var t in _items)
createOne(
ref i,
billboardVertices,
t.Item1 + _world.TranslationVector,
t.Item2,
t.Item3);
_items = null;
_vertexBuffer = Buffer.Vertex.New(Effect.GraphicsDevice, billboardVertices);
_vertexInputLayout = VertexInputLayout.FromBuffer(0, _vertexBuffer);
}
private void createOne(
ref int i,
StaticBillboardVertex[] bv,
Vector3 p,
Vector3 n,
Vector3 front)
{
n.Normalize();
bv[i++] = new StaticBillboardVertex(p, n, front, new Vector2(0, 0));
bv[i++] = new StaticBillboardVertex(p, n, front, new Vector2(1, 0));
bv[i++] = new StaticBillboardVertex(p, n, front, new Vector2(1, 1));
bv[i++] = new StaticBillboardVertex(p, n, front, new Vector2(0, 0));
bv[i++] = new StaticBillboardVertex(p, n, front, new Vector2(1, 1));
bv[i++] = new StaticBillboardVertex(p, n, front, new Vector2(0, 1));
}