// Takes a child node position and returns it's bounds.
func (n *Node) childBounds(pos, divisor math.Vec3) math.Rect3 {
size := n.childSize(divisor)
cb := math.Rect3{
Min: pos,
Max: pos.Add(size),
}
if !n.bounds.Contains(cb.Min) || !n.bounds.Contains(cb.Max) {
fmt.Println(pos)
fmt.Println(n.bounds)
fmt.Println(n.bounds.Contains(cb.Min))
fmt.Println(n.bounds.Contains(cb.Max))
panic("not contained")
}
if !cb.In(n.bounds) {
//fmt.Println("pos ", pos)
//fmt.Println("size ", size)
//fmt.Println("child ", cb)
//fmt.Println("parent", n.bounds)
//panic("")
}
return math.Rect3{
Min: pos,
Max: pos.Add(size),
}
}
// findPlace finds a place in this node or any node below it in the tree where
// r can be placed.
func (n *Node) findPlace(r math.Rect3) (*Node, ChildIndex) {
if !r.In(n.bounds) {
return nil, -1
}
childIndex := n.childFits(r)
if childIndex != -1 && n.children[childIndex] != nil {
cn, ci := n.children[childIndex].findPlace(r)
if cn != nil {
return cn, ci
}
}
return n, -1
}
// find finds this or a distance node where the given rectangle, r, would have
// been placed.
func (n *Node) find(r math.Rect3) *Node {
if !r.In(n.bounds) {
// Not inside this node at all.
return nil
}
// Check children...
for _, child := range n.Children {
ccn := child.find(r)
if ccn != nil {
return ccn
}
}
return n
}
// childFits finds a direct child of this node that can fit the rectangle, r,
// and returns it's bounds.
func (n *Node) childFits(r math.Rect3, divisor math.Vec3) (b math.Rect3, ok bool) {
// Find a child path to create.
nb := n.bounds
sz := n.childSize(divisor)
for x := nb.Min.X; x <= nb.Max.X; x += sz.X {
for y := nb.Min.Y; y <= nb.Max.Y; y += sz.Y {
for z := nb.Min.Z; z <= nb.Max.Z; z += sz.Z {
cb := n.childBounds(math.Vec3{x, y, z}, divisor)
if r.In(cb) {
return cb, true
}
}
}
}
return math.Rect3Zero, false
}
// createPath creates nodes along the needed path up to maxDepth where the
// given spatial's bounds, sb, can be placed.
func (n *Node) createPath(divisor math.Vec3, maxDepth int, sb math.Rect3) *Node {
nb := n.bounds
if !sb.In(nb) {
// Not inside this node at all.
return nil
}
if n.Level+1 > maxDepth {
// Any child would exceed the maximum depth.
return n
}
// Check existing children...
for _, child := range n.Children {
ccn := child.find(sb)
if ccn != nil {
// An existing child node can fit the spatials bounds, sb, so ask
// it to create the path instead.
return child.createPath(divisor, maxDepth, sb)
}
}
// Find a child path to create.
db, ok := n.childFits(sb, divisor)
if ok {
// Create the child.
child := &Node{
Level: n.Level + 1,
bounds: db,
}
n.Children = append(n.Children, child)
ccn := child.createPath(divisor, maxDepth, sb)
if ccn != nil {
return ccn
}
return child
}
return n
}
func (n *Node) fits(sb math.Rect3) bool {
if sb.In(n.bounds) {
return true
}
return false
}