/// <summary>
/// 此 Node 分割
/// </summary>
private void Split()
{
// 左右孩子创建
Left = new OONode();
Right = new OONode();
// 记录孩子Node的深度值
Right.Level = Left.Level = Level + 1;
// 记录孩子Node的父节点
Left.Parent = Right.Parent = this;
// 获取分割轴
SplitAxis = GetSplitAxis(ref Box.Size);
// 获取分割轴的分割值
mSplitValue = Box.Mid[SplitAxis];
// 计算孩子结点的包围盒 size.
Left.Box = Right.Box = Box;
float half = 0.5f * Box.Size[SplitAxis];
// 孩子包围盒的此寸为父节点的一半
Left.Box.Size[SplitAxis] = Right.Box.Size[SplitAxis] = half;
// 在分割轴上, 加减 size,得到新的 中心点
Left.Box.Mid[SplitAxis] = Box.Mid[SplitAxis] - half;
Right.Box.Mid[SplitAxis] = Box.Mid[SplitAxis] + half;
Right.Box.ToMinMax();
Left.Box.ToMinMax();
}
/// <summary>
/// 删除指定结点
/// </summary>
/// <param name="nd">待删除结点</param>
private void DeleteNodes(OONode nd)
{
if (nd == null)
{
return;
}
nd.DeleteItems();
DeleteNodes(nd.Left);
DeleteNodes(nd.Right);
}
private void VisualKDTree(OONode node)
{
node.DrawAABB();
if (node.Left != null)
{
VisualKDTree(node.Left);
}
if (node.Right != null)
{
VisualKDTree(node.Right);
}
}
public OONode()
{
Head = new OOItem();
Tail = new OOItem();
Box = new OOBox(Vector3.one * float.MaxValue, Vector3.one * float.MinValue);
SplitAxis = LEAF;
Visible = 0;
ItemCount = 0;
Left = null;
Right = null;
Parent = null;
Head.Prev = null;
Head.Next = Tail;
Tail.Next = null;
Tail.Prev = Head;
}
/// <summary>
/// 截头体剔除算法入口
/// </summary>
private void FrustumCull()
{
mMinQueue.Clear();
PushBox(Tree.Root, ref Tree.Root.Box);
while (mMinQueue.Size > 0)
{
OONode nd = (OONode)mMinQueue.Dequeue();
if (mFrustum.Test(ref nd.Box) > 0)
{
nd.Distribute(mMaxLevel, mMaxItems);
OOItem itm = nd.Head.Next;
while (itm != nd.Tail)
{
OOModel obj = itm.Obj;
if (obj.TouchId != Tree.TouchCounter)
{
obj.TouchId = Tree.TouchCounter;
if (mFrustum.Test(ref obj.Box) > 0)
{
obj.Next = null;
if (mVisible == null)
{
mVisible = mTail = obj;
}
else
{
mTail.Next = obj;
mTail = obj;
}
}
}
itm = itm.Next;
}
if (nd.SplitAxis != OONode.LEAF)
{
PushBox(nd.Left, ref nd.Left.Box);
PushBox(nd.Right, ref nd.Right.Box);
}
}
}
}
/// <summary>
/// 合并孩子节点
/// </summary>
/// <param name="maxItems"></param>
private void Merge(int maxItems)
{
if (SplitAxis == LEAF)
{
return;
}
if (Left.SplitAxis != LEAF || Right.SplitAxis != LEAF)
{
return;
}
if (Left.ItemCount + Right.ItemCount >= maxItems)
{
return;
}
DoubleCounter++;
OOItem i1;
while (Left.Head.Next != Left.Tail)
{
i1 = Left.Head.Next;
i1.Detach();
i1.Attach(this);
i1.Obj.DoubleId = DoubleCounter;
}
while (Right.Head.Next != Right.Tail)
{
i1 = Right.Head.Next;
i1.Detach();
if (i1.Obj.DoubleId != DoubleCounter)
{
i1.Attach(this);
}
else
{
i1.Unlink();
}
}
Left = Right = null;
SplitAxis = LEAF;
}
/// <summary>
/// 老旧的遮挡剔除算法入口
/// </summary>
private void OcclusionCullOld()
{
Stat[0] = Stat[1] = 0;
Map.Clear();
mMinQueue.Clear();
mMaxQueue.Clear();
PushBox(Tree.Root, ref Tree.Root.Box);
while (mMinQueue.Size > 0)
{
OONode nd = (OONode)mMinQueue.Dequeue();
nd.Distribute(mMaxLevel, mMaxItems);
MinMax(ref nd.Box, ref nd.Box.Zmin, ref nd.Box.Zmax);
if (nd.SplitAxis != OONode.LEAF)
{
if (nd.Visible != 0 || IsVisible(1, ref nd.Box, nd.Box.Zmin) != 0)
{
nd.Visible = 1;
PushBox(nd.Left, ref nd.Left.Box);
PushBox(nd.Right, ref nd.Right.Box);
}
else
{
nd.Visible = 0;
if (nd.Parent != null)
{
nd.Parent.Visible = 0;
}
}
}
else
{
if (IsVisible(1, ref nd.Box, nd.Box.Zmin) != 0)
{
OOItem itm = nd.Head.Next;
while (itm != nd.Tail)
{
if (itm.Obj.TouchId != Tree.TouchCounter)
{
itm.Obj.TouchId = Tree.TouchCounter;
OOModel obj = itm.Obj;
float dis = -Vector3.Dot(obj.Box.Mid, mLook);
float d = Vector3.Dot(mAbsLook, obj.Box.Size);
obj.Box.Zmin = dis - d;
obj.Box.Zmax = dis + d;
if (IsVisible(0, ref obj.Box, 0) != 0)
{
mMaxQueue.Enqueue(obj.Box.Zmax, obj, obj.Box.Zmax);
obj.Next = null;
if (mVisible == null)
{
mVisible = mTail = obj;
}
else
{
mTail.Next = obj;
mTail = obj;
}
}
}
itm = itm.Next;
}
}
if (nd.Parent != null)
{
nd.Parent.Visible = 0;
}
}
}
}
/// <summary>
/// 遮挡剔除 算法入口
/// </summary>
private void OcclusionCull()
{
Stat[0] = Stat[1] = 0;
Map.Clear();
mMinQueue.Clear();
mMaxQueue.Clear();
PushBox2(Tree.Root, ref Tree.Root.Box);
// 按 负无穷范数(最小值) 作为优先权中 遍历
while (mMinQueue.Size > 0)
{
OONode nd = (OONode)mMinQueue.Dequeue();
nd.Distribute(mMaxLevel, mMaxItems);
MinMax(ref nd.Box, ref nd.Box.Zmin, ref nd.Box.Zmax);
if (nd.SplitAxis != OONode.LEAF) // 非叶节点
{
// 该节点存在两个子节点
// 如果 该节点 Visible 为可见 ,则不需要进一步计算
// 如果 该结点 Visible 为不可见,则进一步计算判断可见性
// KDTree的Node不是每次重新分配，带有一定的缓存功能。所以， Visible 可以加速计算
// 存在一个问题：如果所有的物体都分到了一个Node中，可能会不停的划分到最大深度。后期需要优化
if ((nd.Visible != 0) || IsVisible(1, ref nd.Box, nd.Box.Zmin) != 0)
{
// 标记为可见
nd.Visible = 1;
// 父节点可见,接下来判断左右孩子结点的可见性
PushBox2(nd.Left, ref nd.Left.Box);
PushBox2(nd.Right, ref nd.Right.Box);
}
else
{
// 标记为不可见
nd.Visible = 0;
if (nd.Parent != null)
{
nd.Parent.Visible = 0;
}
}
}
else // 叶节点
{
// 叶节点的Box测试
if (IsVisible(1, ref nd.Box, nd.Box.Zmin) != 0)
{
OOItem itm = nd.Head.Next;
// 保存需要绘制的物体，以 Zmax 为优先级排序
while (itm != nd.Tail)
{
if (itm.Obj.TouchId != Tree.TouchCounter)
{
itm.Obj.TouchId = Tree.TouchCounter;
OOModel obj = itm.Obj;
MinMax(ref obj.Box, ref obj.Box.Zmin, ref obj.Box.Zmax);
// 查询物体的Box是否可见
if (IsVisible(0, ref obj.Box, 0) != 0)
{
// 如果一个物体的Box可见，则为待绘制的物体
mMaxQueue.Enqueue(obj.Box.Zmax, obj, obj.Box.Zmax);
obj.Next = null;
if (mVisible == null)
{
mVisible = mTail = obj;
}
else
{
mTail.Next = obj;
mTail = obj;
}
}
}
itm = itm.Next;
}
}
if (nd.Parent != null)
{
nd.Parent.Visible = 0;
}
}
}
#if TEST_DRAW
VisualKDTree(Tree.Root);
if (mMaxQueue.Size > 0)
{
DebugUtils.Info("OcclusionCull", "Before Max Left: ", mMaxQueue.Size);
FlushOccluders(float.MaxValue);
DebugUtils.Info("OcclusionCull", "After Max Left: ", mMaxQueue.Size);
}
Map.DrawScreenShot();
#endif
}
public OOKDTree()
{
Root = new OONode();
Root.Level = 0;
}
