private void UpdateNode(Node node, bool frustumCulling, GameTime gameTime)
{
node.Visible = true;
if (frustumCulling)
{
ContainmentType result = ViewFrustum.Contains(GetBoundingBox(node));
if (result == ContainmentType.Disjoint)
node.Visible = false;
else if (result == ContainmentType.Contains)
frustumCulling = false;
}
if (!node.Visible)
return;
if (node.Children != null)
foreach (Node child in node.Children)
UpdateNode(child, frustumCulling, gameTime);
if (node.Block != null)
node.Block.Update(gameTime);
}
private void InitializeQuadtree()
{
root = InitializeNode(BlockCount, 0, 0);
}
private BoundingBox GetBoundingBox(Node node)
{
Vector3 min = node.BoundingBox.Min;
Vector3 max = node.BoundingBox.Max;
if (!HeightmapEnabled || Bumpiness == 0.0f)
{
min.Y = HeightOffset - 1.0f;
max.Y = HeightOffset + 1.0f;
}
else
{
min.Y *= Bumpiness;
max.Y *= Bumpiness;
}
if (min.Y > max.Y)
{
float y = min.Y;
min.Y = max.Y;
max.Y = y;
}
return new BoundingBox(min, max);
}
private Node InitializeNode(int count, int x, int y)
{
Node node = new Node();
if (count > 1)
{
node.Children = new List<Node>();
for (int i = 0; i < 2; i++)
for (int j = 0; j < 2; j++ )
node.Children.Add(InitializeNode(count / 2, x + i * count / 2, y + j * count / 2));
foreach (Node child in node.Children)
node.BoundingBox = BoundingBox.CreateMerged(node.BoundingBox, child.BoundingBox);
}
else
{
node.Block = blocks[x, y];
node.BoundingBox = node.Block.BoundingBox;
}
return node;
}
private void DrawNode(Node node)
{
if (!node.Visible)
return;
if (node.Children != null)
foreach (Node child in node.Children)
DrawNode(child);
else
DrawBlock(node.Block);
}
