internal void Update(GameTime gameTime, ICamera Camera)
{
ViewFrustrum.Matrix = Camera.ViewProjection;
CameraPosition = Camera.Position;
//Corners 0-3 = near plane clockwise, Corners 4-7 = far plane clockwise
ViewFrustrum.GetCorners(VFCorners);
var clip = ClippingFrustrum.FromFrustrumCorners(VFCorners, CameraPosition);
ClipShape = clip.ProjectToTargetY(_position.Y);
_lastCameraPosition = _cameraPosition;
IndexCount = 0;
_rootNode.Merge();
_rootNode.EnforceMinimumDepth();
_activeNode = _rootNode.DeepestNodeWithPoint(ClipShape.ViewPoint);
if (_activeNode != null)
{
_activeNode.Split();
}
_rootNode.SetActiveVertices();
_buffers.UpdateIndexBuffer(Indices, IndexCount);
_buffers.SwapBuffer();
}
/// <summary>
/// Add child nodes
/// </summary>
private void AddChildren()
{
//Add top left (northwest) child
ChildTopLeft = new QuadNode(NodeType.TopLeft, _nodeSize / 2, _nodeDepth + 1, this, _parentTree, VertexTopLeft.Index);
//Add top right (northeast) child
ChildTopRight = new QuadNode(NodeType.TopRight, _nodeSize / 2, _nodeDepth + 1, this, _parentTree, VertexTop.Index);
//Add bottom left (southwest) child
ChildBottomLeft = new QuadNode(NodeType.BottomLeft, _nodeSize / 2, _nodeDepth + 1, this, _parentTree, VertexLeft.Index);
//Add bottom right (southeast) child
ChildBottomRight = new QuadNode(NodeType.BottomRight, _nodeSize / 2, _nodeDepth + 1, this, _parentTree, VertexCenter.Index);
HasChildren = true;
}
internal QuadTree(Vector3 position, List<VertexPositionNormalTexture> positions, Texture2D heightMap, Matrix viewMatrix, Matrix projectionMatrix, GraphicsDevice device)
{
Device = device;
_position = position;
_topNodeSize = heightMap.Width - 1;
_vertices = new TreeVertexCollection(positions);
_buffers = new BufferManager(_vertices.Vertices, device);
_rootNode = new QuadNode(NodeType.FullNode, _topNodeSize, 1, null, this, 0);
//Initialize the bounding frustrum to be used for culling later.
ViewFrustrum = new BoundingFrustum(viewMatrix * projectionMatrix);
//Construct an array large enough to hold all of the indices we'll need
Indices = new int[((heightMap.Width + 1) * (heightMap.Height + 1)) * 3];
Cull = false;
}
internal QuadTree(Vector3 position, List <VertexPositionNormalTexture> positions, Texture2D heightMap, Matrix viewMatrix, Matrix projectionMatrix, GraphicsDevice device)
{
Device = device;
_position = position;
_topNodeSize = heightMap.Width - 1;
_vertices = new TreeVertexCollection(positions);
_buffers = new BufferManager(_vertices.Vertices, device);
_rootNode = new QuadNode(NodeType.FullNode, _topNodeSize, 1, null, this, 0);
//Initialize the bounding frustrum to be used for culling later.
ViewFrustrum = new BoundingFrustum(viewMatrix * projectionMatrix);
//Construct an array large enough to hold all of the indices we'll need
Indices = new int[((heightMap.Width + 1) * (heightMap.Height + 1)) * 3];
Cull = false;
}
internal QuadNode(NodeType nodeType, int nodeSize, int nodeDepth, QuadNode parent, QuadTree parentTree, int positionIndex)
{
NodeType = nodeType;
_nodeSize = nodeSize;
_nodeDepth = nodeDepth;
_positionIndex = positionIndex;
_parent = parent;
_parentTree = parentTree;
//Add the 9 vertices
AddVertices();
var tl = new Vector2(_parentTree.Vertices[VertexTopLeft.Index].Position.X, _parentTree.Vertices[VertexTopLeft.Index].Position.Z);
var br = new Vector2(_parentTree.Vertices[VertexBottomRight.Index].Position.X, _parentTree.Vertices[VertexBottomRight.Index].Position.Z);
Bounds = Culling.Rectangle.FromPoints(tl, br);
if (nodeSize >= 4)
{
AddChildren();
}
//Make call to UpdateNeighbors from the parent node only.
//This will update neighbors recursively for the children
//as well. This ensures all nodes are created prior to
//updating neighbors.
if (_nodeDepth == 1)
{
AddNeighbors();
VertexTopLeft.Activated = true;
VertexTopRight.Activated = true;
VertexCenter.Activated = true;
VertexBottomLeft.Activated = true;
VertexBottomRight.Activated = true;
}
}
internal QuadNode(NodeType nodeType, int nodeSize, int nodeDepth, QuadNode parent, QuadTree parentTree, int positionIndex)
{
NodeType = nodeType;
_nodeSize = nodeSize;
_nodeDepth = nodeDepth;
_positionIndex = positionIndex;
_parent = parent;
_parentTree = parentTree;
//Add the 9 vertices
AddVertices();
var tl = new Vector2(_parentTree.Vertices[VertexTopLeft.Index].Position.X, _parentTree.Vertices[VertexTopLeft.Index].Position.Z);
var br = new Vector2(_parentTree.Vertices[VertexBottomRight.Index].Position.X, _parentTree.Vertices[VertexBottomRight.Index].Position.Z);
Bounds = Culling.Rectangle.FromPoints(tl, br);
if (nodeSize >= 4)
AddChildren();
//Make call to UpdateNeighbors from the parent node only.
//This will update neighbors recursively for the children
//as well. This ensures all nodes are created prior to
//updating neighbors.
if (_nodeDepth == 1)
{
AddNeighbors();
VertexTopLeft.Activated = true;
VertexTopRight.Activated = true;
VertexCenter.Activated = true;
VertexBottomLeft.Activated = true;
VertexBottomRight.Activated = true;
}
}
/// <summary>
/// Make sure neighbor parents are split to ensure
/// consistency with vertex sharing and tessellation.
/// </summary>
private static void EnsureNeighborParentSplit(QuadNode neighbor)
{
//Checking for null neighbor and null parent in case
//we recode for additional quad trees in the future.
if (neighbor != null && neighbor.Parent != null)
if (!neighbor.Parent.IsSplit)
neighbor.Parent.Split();
}
/// <summary>
/// Add child nodes
/// </summary>
private void AddChildren()
{
//Add top left (northwest) child
ChildTopLeft = new QuadNode(NodeType.TopLeft, _nodeSize / 2, _nodeDepth + 1, this, _parentTree, VertexTopLeft.Index);
//Add top right (northeast) child
ChildTopRight = new QuadNode(NodeType.TopRight, _nodeSize / 2, _nodeDepth + 1, this, _parentTree, VertexTop.Index);
//Add bottom left (southwest) child
ChildBottomLeft = new QuadNode(NodeType.BottomLeft, _nodeSize / 2, _nodeDepth + 1, this, _parentTree, VertexLeft.Index);
//Add bottom right (southeast) child
ChildBottomRight = new QuadNode(NodeType.BottomRight, _nodeSize / 2, _nodeDepth + 1, this, _parentTree, VertexCenter.Index);
HasChildren = true;
}