diff --git a/gen.sh b/gen.sh index db85adc..4d133ab 100755 --- a/gen.sh +++ b/gen.sh @@ -21,7 +21,7 @@ gen(){ } for i in {1..4}; do - gen $i true + #gen $i true gen $i false done diff --git a/rtree.go b/rtree.go new file mode 100644 index 0000000..d3a942c --- /dev/null +++ b/rtree.go @@ -0,0 +1,226 @@ +package rtree + +import ( + d1 "d1" + d2 "d2" + d3 "d3" + d4 "d4" + "math" +) + +type Iterator func(item Item) bool +type Item interface { + Rect() (min []float64, max []float64) +} + +type RTree struct { + tr1 *d1.RTree + tr2 *d2.RTree + tr3 *d3.RTree + tr4 *d4.RTree +} + +func New() *RTree { + return &RTree{ + tr1: d1.NewRTree(), + tr2: d2.NewRTree(), + tr3: d3.NewRTree(), + tr4: d4.NewRTree(), + } +} + +func (tr *RTree) Insert(item Item) { + if item == nil { + panic("nil item being added to RTree") + } + min, max := item.Rect() + if len(min) != len(max) { + panic("invalid item rectangle") + } + switch len(min) { + default: + panic("invalid dimension") + case 1: + var amin, amax [1]float64 + for i := 0; i < len(min); i++ { + amin[i], amax[i] = min[i], max[i] + } + tr.tr1.Insert(amin, amax, item) + case 2: + var amin, amax [2]float64 + for i := 0; i < len(min); i++ { + amin[i], amax[i] = min[i], max[i] + } + tr.tr2.Insert(amin, amax, item) + case 3: + var amin, amax [3]float64 + for i := 0; i < len(min); i++ { + amin[i], amax[i] = min[i], max[i] + } + tr.tr3.Insert(amin, amax, item) + case 4: + var amin, amax [4]float64 + for i := 0; i < len(min); i++ { + amin[i], amax[i] = min[i], max[i] + } + tr.tr4.Insert(amin, amax, item) + } +} + +func (tr *RTree) Remove(item Item) { + if item == nil { + panic("nil item being added to RTree") + } + min, max := item.Rect() + if len(min) != len(max) { + panic("invalid item rectangle") + } + switch len(min) { + default: + panic("invalid dimension") + case 1: + var amin, amax [1]float64 + for i := 0; i < len(min); i++ { + amin[i], amax[i] = min[i], max[i] + } + tr.tr1.Remove(amin, amax, item) + case 2: + var amin, amax [2]float64 + for i := 0; i < len(min); i++ { + amin[i], amax[i] = min[i], max[i] + } + tr.tr2.Remove(amin, amax, item) + case 3: + var amin, amax [3]float64 + for i := 0; i < len(min); i++ { + amin[i], amax[i] = min[i], max[i] + } + tr.tr3.Remove(amin, amax, item) + case 4: + var amin, amax [4]float64 + for i := 0; i < len(min); i++ { + amin[i], amax[i] = min[i], max[i] + } + tr.tr4.Remove(amin, amax, item) + } +} +func (tr *RTree) Reset() { + tr.tr1 = d1.NewRTree() + tr.tr2 = d2.NewRTree() + tr.tr3 = d3.NewRTree() + tr.tr4 = d4.NewRTree() +} +func (tr *RTree) Count() int { + return tr.tr1.Count() + tr.tr2.Count() + tr.tr3.Count() + tr.tr4.Count() +} +func (tr *RTree) Search(bounds Item, iter Iterator) { + if bounds == nil { + panic("nil item being added to RTree") + } + min, max := bounds.Rect() + if len(min) != len(max) { + panic("invalid item rectangle") + } + switch len(min) { + default: + panic("invalid dimension") + case 1, 2, 3, 4: + } + if !tr.search1(min, max, iter) { + return + } + if !tr.search2(min, max, iter) { + return + } + if !tr.search3(min, max, iter) { + return + } + if !tr.search4(min, max, iter) { + return + } +} + +func (tr *RTree) search1(min, max []float64, iter Iterator) bool { + var amin, amax [1]float64 + for i := 0; i < 1; i++ { + if i < len(min) { + amin[i] = min[i] + amax[i] = max[i] + } else { + amin[i] = math.Inf(-1) + amax[i] = math.Inf(+1) + } + } + ended := false + tr.tr1.Search(amin, amax, func(dataID, context interface{}) bool { + if !iter(dataID.(Item)) { + ended = true + return false + } + return true + }, nil) + return !ended +} +func (tr *RTree) search2(min, max []float64, iter Iterator) bool { + var amin, amax [2]float64 + for i := 0; i < 2; i++ { + if i < len(min) { + amin[i] = min[i] + amax[i] = max[i] + } else { + amin[i] = math.Inf(-1) + amax[i] = math.Inf(+1) + } + } + ended := false + tr.tr2.Search(amin, amax, func(dataID, context interface{}) bool { + if !iter(dataID.(Item)) { + ended = true + return false + } + return true + }, nil) + return !ended +} +func (tr *RTree) search3(min, max []float64, iter Iterator) bool { + var amin, amax [3]float64 + for i := 0; i < 3; i++ { + if i < len(min) { + amin[i] = min[i] + amax[i] = max[i] + } else { + amin[i] = math.Inf(-1) + amax[i] = math.Inf(+1) + } + } + ended := false + tr.tr3.Search(amin, amax, func(dataID, context interface{}) bool { + if !iter(dataID.(Item)) { + ended = true + return false + } + return true + }, nil) + return !ended +} +func (tr *RTree) search4(min, max []float64, iter Iterator) bool { + var amin, amax [4]float64 + for i := 0; i < 4; i++ { + if i < len(min) { + amin[i] = min[i] + amax[i] = max[i] + } else { + amin[i] = math.Inf(-1) + amax[i] = math.Inf(+1) + } + } + ended := false + tr.tr4.Search(amin, amax, func(dataID, context interface{}) bool { + if !iter(dataID.(Item)) { + ended = true + return false + } + return true + }, nil) + return !ended +} diff --git a/rtree_base.go b/rtree_base.go index 268fc0e..5c64fa3 100644 --- a/rtree_base.go +++ b/rtree_base.go @@ -56,7 +56,7 @@ const ( USE_SPHERICAL_VOLUME = true // Better split classification, may be slower on some systems ) -type ResultCallback func(dataID interface{}, context interface{}) bool +type ResultCallback func(dataID, context interface{}) bool var unitSphereVolume float64 diff --git a/rtree_test.go b/rtree_test.go new file mode 100644 index 0000000..70045f9 --- /dev/null +++ b/rtree_test.go @@ -0,0 +1,96 @@ +package rtree + +import ( + "fmt" + "math/rand" + "testing" + "time" +) + +type tRect []float64 + +func (r *tRect) Arr() []float64 { + return []float64(*r) +} +func (r *tRect) Rect() (min, max []float64) { + return r.Arr()[:len(r.Arr())/2], r.Arr()[len(r.Arr())/2:] +} + +func (r *tRect) String() string { + min, max := r.Rect() + return fmt.Sprintf("%v,%v", min, max) +} +func tRandRect(dims int) *tRect { + if dims == -1 { + dims = rand.Int()%4 + 1 + } + r := tRect(make([]float64, dims*2)) + for j := 0; j < dims; j++ { + minf := rand.Float64()*200 - 100 + maxf := rand.Float64()*200 - 100 + if minf > maxf { + minf, maxf = maxf, minf + } + r[j] = minf + r[dims+j] = maxf + } + return &r +} +func TestRTree(t *testing.T) { + tr := New() + + tr.Insert(&tRect{10, 10, 10, 10, 20, 20, 20, 20}) + tr.Insert(&tRect{10, 10, 10, 20, 20, 20}) + tr.Insert(&tRect{10, 10, 20, 20}) + tr.Insert(&tRect{10, 20}) + + if tr.Count() != 4 { + t.Fatalf("expecting %v, got %v", 4, tr.Count()) + } + + var count int + tr.Search(&tRect{0, 0, 0, 100, 100, 5}, func(item Item) bool { + count++ + return true + }) + + if count != 2 { + t.Fatalf("expecting %v, got %v", 2, count) + } +} + +func TestInsert(t *testing.T) { + rand.Seed(time.Now().UnixNano()) + n := 50000 + tr := New() + var r2arr []*tRect + for i := 0; i < n; i++ { + r := tRandRect(-1) + if len(r.Arr()) == 4 { + r2arr = append(r2arr, r) + } + tr.Insert(r) + } + if tr.Count() != n { + t.Fatalf("expecting %v, got %v", n, tr.Count()) + } + var count int + tr.Search(&tRect{-100, -100, -100, -100, 100, 100, 100, 100}, func(item Item) bool { + if len(item.(*tRect).Arr()) == 4 { + count++ + } + return true + }) + p := float64(count) / float64(n) + + if p < .23 || p > .27 { + t.Fatalf("bad random range, expected between 0.24-0.26, got %v", p) + } + for _, r := range r2arr { + tr.Remove(r) + } + total := tr.Count() + count + if total != n { + t.Fatalf("expected %v, got %v", n, total) + } +} diff --git a/vendor/d1/rtree.go b/vendor/d1/rtree.go index 0a657fa..e483f0f 100644 --- a/vendor/d1/rtree.go +++ b/vendor/d1/rtree.go @@ -56,7 +56,7 @@ const ( USE_SPHERICAL_VOLUME = true // Better split classification, may be slower on some systems ) -type ResultCallback func(dataID interface{}, context interface{}) bool +type ResultCallback func(dataID, context interface{}) bool var unitSphereVolume float64 diff --git a/vendor/d1d/rtree.go b/vendor/d1d/rtree.go deleted file mode 100644 index c177cee..0000000 --- a/vendor/d1d/rtree.go +++ /dev/null @@ -1,815 +0,0 @@ -//generated; DO NOT EDIT! - -/* - -TITLE - - R-TREES: A DYNAMIC INDEX STRUCTURE FOR SPATIAL SEARCHING - -DESCRIPTION - - A Go version of the RTree algorithm. - For more information please read the comments in rtree.go - -AUTHORS - - * 1983 Original algorithm and test code by Antonin Guttman and Michael Stonebraker, UC Berkely - * 1994 ANCI C ported from original test code by Melinda Green - melinda@superliminal.com - * 1995 Sphere volume fix for degeneracy problem submitted by Paul Brook - * 2004 Templated C++ port by Greg Douglas - * 2016 Go port by Josh Baker - -LICENSE: - - Entirely free for all uses. Enjoy! - -*/ - -// Implementation of RTree, a multidimensional bounding rectangle tree. -package rtree - -import "math" - -func Min(a, b float64) float64 { - if a < b { - return a - } - return b -} -func Max(a, b float64) float64 { - if a > b { - return a - } - return b -} -func ASSERT(condition bool) { - if _DEBUG && !condition { - panic("assertion failed") - } -} - -const ( - _DEBUG = true - NUMDIMS = 1 - MAXNODES = 8 - MINNODES = MAXNODES / 2 - USE_SPHERICAL_VOLUME = true // Better split classification, may be slower on some systems -) - -type ResultCallback func(dataID interface{}, context interface{}) bool - -var unitSphereVolume float64 - -func init() { - // Precomputed volumes of the unit spheres for the first few dimensions - unitSphereVolume = []float64{ - 0.000000, 2.000000, 3.141593, // Dimension 0,1,2 - 4.188790, 4.934802, 5.263789, // Dimension 3,4,5 - 5.167713, 4.724766, 4.058712, // Dimension 6,7,8 - 3.298509, 2.550164, 1.884104, // Dimension 9,10,11 - 1.335263, 0.910629, 0.599265, // Dimension 12,13,14 - 0.381443, 0.235331, 0.140981, // Dimension 15,16,17 - 0.082146, 0.046622, 0.025807, // Dimension 18,19,20 - }[NUMDIMS] -} - -type RTree struct { - root *Node ///< Root of tree - unitSphereVolume float64 ///< Unit sphere constant for required number of dimensions -} - -/// Minimal bounding rectangle (n-dimensional) -type Rect struct { - min [NUMDIMS]float64 ///< Min dimensions of bounding box - max [NUMDIMS]float64 ///< Max dimensions of bounding box -} - -/// May be data or may be another subtree -/// The parents level determines this. -/// If the parents level is 0, then this is data -type Branch struct { - rect Rect ///< Bounds - child *Node ///< Child node - data interface{} ///< Data Id or Ptr -} - -/// Node for each branch level -type Node struct { - count int ///< Count - level int ///< Leaf is zero, others positive - branch [MAXNODES]Branch ///< Branch -} - -func (node *Node) IsInternalNode() bool { - return (node.level > 0) // Not a leaf, but a internal node -} -func (node *Node) IsLeaf() bool { - return (node.level == 0) // A leaf, contains data -} - -/// A link list of nodes for reinsertion after a delete operation -type ListNode struct { - next *ListNode ///< Next in list - node *Node ///< Node -} - -const NOT_TAKEN = -1 // indicates that position - -/// Variables for finding a split partition -type PartitionVars struct { - partition [MAXNODES + 1]int - total int - minFill int - count [2]int - cover [2]Rect - area [2]float64 - - branchBuf [MAXNODES + 1]Branch - branchCount int - coverSplit Rect - coverSplitArea float64 -} - -func NewRTree() *RTree { - ASSERT(MAXNODES > MINNODES) - ASSERT(MINNODES > 0) - - // We only support machine word size simple data type eg. integer index or object pointer. - // Since we are storing as union with non data branch - //ASSERT(sizeof(DATATYPE) == sizeof(void*) || sizeof(DATATYPE) == sizeof(int)); - - return &RTree{ - root: &Node{}, - } -} - -/// Insert entry -/// \param a_min Min of bounding rect -/// \param a_max Max of bounding rect -/// \param a_dataId Positive Id of data. Maybe zero, but negative numbers not allowed. -func (tr *RTree) Insert(min, max [NUMDIMS]float64, dataId interface{}) { - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(min[index] <= max[index]) - } - } //_DEBUG - var branch Branch - branch.data = dataId - branch.child = nil - for axis := 0; axis < NUMDIMS; axis++ { - branch.rect.min[axis] = min[axis] - branch.rect.max[axis] = max[axis] - } - InsertRect(&branch, &tr.root, 0) -} - -/// Remove entry -/// \param a_min Min of bounding rect -/// \param a_max Max of bounding rect -/// \param a_dataId Positive Id of data. Maybe zero, but negative numbers not allowed. -func (tr *RTree) Remove(min, max [NUMDIMS]float64, dataId interface{}) { - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(min[index] <= max[index]) - } - } //_DEBUG - var rect Rect - for axis := 0; axis < NUMDIMS; axis++ { - rect.min[axis] = min[axis] - rect.max[axis] = max[axis] - } - RemoveRect(&rect, dataId, &tr.root) -} - -/// Find all within search rectangle -/// \param a_min Min of search bounding rect -/// \param a_max Max of search bounding rect -/// \param a_searchResult Search result array. Caller should set grow size. Function will reset, not append to array. -/// \param a_resultCallback Callback function to return result. Callback should return 'true' to continue searching -/// \param a_context User context to pass as parameter to a_resultCallback -/// \return Returns the number of entries found -func (tr *RTree) Search(min, max [NUMDIMS]float64, resultCallback ResultCallback, context interface{}) int { - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(min[index] <= max[index]) - } - } //_DEBUG - var rect Rect - for axis := 0; axis < NUMDIMS; axis++ { - rect.min[axis] = min[axis] - rect.max[axis] = max[axis] - } - // NOTE: May want to return search result another way, perhaps returning the number of found elements here. - - foundCount := 0 - Search(tr.root, &rect, &foundCount, resultCallback, context) - return foundCount -} - -/// Count the data elements in this container. This is slow as no internal counter is maintained. -func (tr *RTree) Count() int { - var count int - CountRec(tr.root, &count) - return count -} - -func CountRec(node *Node, count *int) { - if node.IsInternalNode() { // not a leaf node - for index := 0; index < node.count; index++ { - CountRec(node.branch[index].child, count) - } - } else { // A leaf node - *count += node.count - } -} - -/// Remove all entries from tree -func (tr *RTree) RemoveAll() { - // Delete all existing nodes - tr.root = &Node{} -} - -func InitNode(node *Node) { - node.count = 0 - node.level = -1 -} - -func InitRect(rect *Rect) { - for index := 0; index < NUMDIMS; index++ { - rect.min[index] = 0 - rect.max[index] = 0 - } -} - -// Inserts a new data rectangle into the index structure. -// Recursively descends tree, propagates splits back up. -// Returns 0 if node was not split. Old node updated. -// If node was split, returns 1 and sets the pointer pointed to by -// new_node to point to the new node. Old node updated to become one of two. -// The level argument specifies the number of steps up from the leaf -// level to insert; e.g. a data rectangle goes in at level = 0. -func InsertRectRec(branch *Branch, node *Node, newNode **Node, level int) bool { - ASSERT(node != nil && newNode != nil) - ASSERT(level >= 0 && level <= node.level) - - // recurse until we reach the correct level for the new record. data records - // will always be called with a_level == 0 (leaf) - if node.level > level { - // Still above level for insertion, go down tree recursively - var otherNode *Node - //var newBranch Branch - - // find the optimal branch for this record - index := PickBranch(&branch.rect, node) - - // recursively insert this record into the picked branch - childWasSplit := InsertRectRec(branch, node.branch[index].child, &otherNode, level) - - if !childWasSplit { - // Child was not split. Merge the bounding box of the new record with the - // existing bounding box - node.branch[index].rect = CombineRect(&branch.rect, &(node.branch[index].rect)) - return false - } else { - // Child was split. The old branches are now re-partitioned to two nodes - // so we have to re-calculate the bounding boxes of each node - node.branch[index].rect = NodeCover(node.branch[index].child) - var newBranch Branch - newBranch.child = otherNode - newBranch.rect = NodeCover(otherNode) - - // The old node is already a child of a_node. Now add the newly-created - // node to a_node as well. a_node might be split because of that. - return AddBranch(&newBranch, node, newNode) - } - } else if node.level == level { - // We have reached level for insertion. Add rect, split if necessary - return AddBranch(branch, node, newNode) - } else { - // Should never occur - ASSERT(false) - return false - } -} - -// Insert a data rectangle into an index structure. -// InsertRect provides for splitting the root; -// returns 1 if root was split, 0 if it was not. -// The level argument specifies the number of steps up from the leaf -// level to insert; e.g. a data rectangle goes in at level = 0. -// InsertRect2 does the recursion. -// -func InsertRect(branch *Branch, root **Node, level int) bool { - ASSERT(root != nil) - ASSERT(level >= 0 && level <= (*root).level) - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(branch.rect.min[index] <= branch.rect.max[index]) - } - } //_DEBUG - - var newNode *Node - - if InsertRectRec(branch, *root, &newNode, level) { // Root split - - // Grow tree taller and new root - newRoot := &Node{} - newRoot.level = (*root).level + 1 - - var newBranch Branch - - // add old root node as a child of the new root - newBranch.rect = NodeCover(*root) - newBranch.child = *root - AddBranch(&newBranch, newRoot, nil) - - // add the split node as a child of the new root - newBranch.rect = NodeCover(newNode) - newBranch.child = newNode - AddBranch(&newBranch, newRoot, nil) - - // set the new root as the root node - *root = newRoot - - return true - } - - return false -} - -// Find the smallest rectangle that includes all rectangles in branches of a node. -func NodeCover(node *Node) Rect { - ASSERT(node != nil) - - rect := node.branch[0].rect - for index := 1; index < node.count; index++ { - rect = CombineRect(&rect, &(node.branch[index].rect)) - } - - return rect -} - -// Add a branch to a node. Split the node if necessary. -// Returns 0 if node not split. Old node updated. -// Returns 1 if node split, sets *new_node to address of new node. -// Old node updated, becomes one of two. -func AddBranch(branch *Branch, node *Node, newNode **Node) bool { - ASSERT(branch != nil) - ASSERT(node != nil) - - if node.count < MAXNODES { // Split won't be necessary - - node.branch[node.count] = *branch - node.count++ - - return false - } else { - ASSERT(newNode != nil) - - SplitNode(node, branch, newNode) - return true - } -} - -// Disconnect a dependent node. -// Caller must return (or stop using iteration index) after this as count has changed -func DisconnectBranch(node *Node, index int) { - ASSERT(node != nil && (index >= 0) && (index < MAXNODES)) - ASSERT(node.count > 0) - - // Remove element by swapping with the last element to prevent gaps in array - node.branch[index] = node.branch[node.count-1] - - node.count-- -} - -// Pick a branch. Pick the one that will need the smallest increase -// in area to accomodate the new rectangle. This will result in the -// least total area for the covering rectangles in the current node. -// In case of a tie, pick the one which was smaller before, to get -// the best resolution when searching. -func PickBranch(rect *Rect, node *Node) int { - ASSERT(rect != nil && node != nil) - - var firstTime bool = true - var increase float64 - var bestIncr float64 = -1 - var area float64 - var bestArea float64 - var best int - var tempRect Rect - - for index := 0; index < node.count; index++ { - curRect := &node.branch[index].rect - area = CalcRectVolume(curRect) - tempRect = CombineRect(rect, curRect) - increase = CalcRectVolume(&tempRect) - area - if (increase < bestIncr) || firstTime { - best = index - bestArea = area - bestIncr = increase - firstTime = false - } else if (increase == bestIncr) && (area < bestArea) { - best = index - bestArea = area - bestIncr = increase - } - } - return best -} - -// Combine two rectangles into larger one containing both -func CombineRect(rectA, rectB *Rect) Rect { - ASSERT(rectA != nil && rectB != nil) - - var newRect Rect - - for index := 0; index < NUMDIMS; index++ { - newRect.min[index] = Min(rectA.min[index], rectB.min[index]) - newRect.max[index] = Max(rectA.max[index], rectB.max[index]) - } - - return newRect -} - -// Split a node. -// Divides the nodes branches and the extra one between two nodes. -// Old node is one of the new ones, and one really new one is created. -// Tries more than one method for choosing a partition, uses best result. -func SplitNode(node *Node, branch *Branch, newNode **Node) { - ASSERT(node != nil) - ASSERT(branch != nil) - - // Could just use local here, but member or external is faster since it is reused - var localVars PartitionVars - parVars := &localVars - - // Load all the branches into a buffer, initialize old node - GetBranches(node, branch, parVars) - - // Find partition - ChoosePartition(parVars, MINNODES) - - // Create a new node to hold (about) half of the branches - *newNode = &Node{} - (*newNode).level = node.level - - // Put branches from buffer into 2 nodes according to the chosen partition - node.count = 0 - LoadNodes(node, *newNode, parVars) - - ASSERT((node.count + (*newNode).count) == parVars.total) -} - -// Calculate the n-dimensional volume of a rectangle -func RectVolume(rect *Rect) float64 { - ASSERT(rect != nil) - - var volume float64 = 1 - - for index := 0; index < NUMDIMS; index++ { - volume *= rect.max[index] - rect.min[index] - } - - ASSERT(volume >= 0) - - return volume -} - -// The exact volume of the bounding sphere for the given Rect -func RectSphericalVolume(rect *Rect) float64 { - ASSERT(rect != nil) - - var sumOfSquares float64 = 0 - var radius float64 - - for index := 0; index < NUMDIMS; index++ { - halfExtent := (rect.max[index] - rect.min[index]) * 0.5 - sumOfSquares += halfExtent * halfExtent - } - - radius = math.Sqrt(sumOfSquares) - - // Pow maybe slow, so test for common dims like 2,3 and just use x*x, x*x*x. - if NUMDIMS == 4 { - return (radius * radius * radius * radius * unitSphereVolume) - } else if NUMDIMS == 3 { - return (radius * radius * radius * unitSphereVolume) - } else if NUMDIMS == 2 { - return (radius * radius * unitSphereVolume) - } else { - return (math.Pow(radius, NUMDIMS) * unitSphereVolume) - } -} - -// Use one of the methods to calculate retangle volume -func CalcRectVolume(rect *Rect) float64 { - if USE_SPHERICAL_VOLUME { - return RectSphericalVolume(rect) // Slower but helps certain merge cases - } else { // RTREE_USE_SPHERICAL_VOLUME - return RectVolume(rect) // Faster but can cause poor merges - } // RTREE_USE_SPHERICAL_VOLUME -} - -// Load branch buffer with branches from full node plus the extra branch. -func GetBranches(node *Node, branch *Branch, parVars *PartitionVars) { - ASSERT(node != nil) - ASSERT(branch != nil) - - ASSERT(node.count == MAXNODES) - - // Load the branch buffer - for index := 0; index < MAXNODES; index++ { - parVars.branchBuf[index] = node.branch[index] - } - parVars.branchBuf[MAXNODES] = *branch - parVars.branchCount = MAXNODES + 1 - - // Calculate rect containing all in the set - parVars.coverSplit = parVars.branchBuf[0].rect - for index := 1; index < MAXNODES+1; index++ { - parVars.coverSplit = CombineRect(&parVars.coverSplit, &parVars.branchBuf[index].rect) - } - parVars.coverSplitArea = CalcRectVolume(&parVars.coverSplit) -} - -// Method #0 for choosing a partition: -// As the seeds for the two groups, pick the two rects that would waste the -// most area if covered by a single rectangle, i.e. evidently the worst pair -// to have in the same group. -// Of the remaining, one at a time is chosen to be put in one of the two groups. -// The one chosen is the one with the greatest difference in area expansion -// depending on which group - the rect most strongly attracted to one group -// and repelled from the other. -// If one group gets too full (more would force other group to violate min -// fill requirement) then other group gets the rest. -// These last are the ones that can go in either group most easily. -func ChoosePartition(parVars *PartitionVars, minFill int) { - ASSERT(parVars != nil) - - var biggestDiff float64 - var group, chosen, betterGroup int - - InitParVars(parVars, parVars.branchCount, minFill) - PickSeeds(parVars) - - for ((parVars.count[0] + parVars.count[1]) < parVars.total) && - (parVars.count[0] < (parVars.total - parVars.minFill)) && - (parVars.count[1] < (parVars.total - parVars.minFill)) { - biggestDiff = -1 - for index := 0; index < parVars.total; index++ { - if NOT_TAKEN == parVars.partition[index] { - curRect := &parVars.branchBuf[index].rect - rect0 := CombineRect(curRect, &parVars.cover[0]) - rect1 := CombineRect(curRect, &parVars.cover[1]) - growth0 := CalcRectVolume(&rect0) - parVars.area[0] - growth1 := CalcRectVolume(&rect1) - parVars.area[1] - diff := growth1 - growth0 - if diff >= 0 { - group = 0 - } else { - group = 1 - diff = -diff - } - - if diff > biggestDiff { - biggestDiff = diff - chosen = index - betterGroup = group - } else if (diff == biggestDiff) && (parVars.count[group] < parVars.count[betterGroup]) { - chosen = index - betterGroup = group - } - } - } - Classify(chosen, betterGroup, parVars) - } - - // If one group too full, put remaining rects in the other - if (parVars.count[0] + parVars.count[1]) < parVars.total { - if parVars.count[0] >= parVars.total-parVars.minFill { - group = 1 - } else { - group = 0 - } - for index := 0; index < parVars.total; index++ { - if NOT_TAKEN == parVars.partition[index] { - Classify(index, group, parVars) - } - } - } - - ASSERT((parVars.count[0] + parVars.count[1]) == parVars.total) - ASSERT((parVars.count[0] >= parVars.minFill) && - (parVars.count[1] >= parVars.minFill)) -} - -// Copy branches from the buffer into two nodes according to the partition. -func LoadNodes(nodeA, nodeB *Node, parVars *PartitionVars) { - ASSERT(nodeA != nil) - ASSERT(nodeB != nil) - ASSERT(parVars != nil) - - for index := 0; index < parVars.total; index++ { - ASSERT(parVars.partition[index] == 0 || parVars.partition[index] == 1) - - targetNodeIndex := parVars.partition[index] - targetNodes := []*Node{nodeA, nodeB} - - // It is assured that AddBranch here will not cause a node split. - nodeWasSplit := AddBranch(&parVars.branchBuf[index], targetNodes[targetNodeIndex], nil) - ASSERT(!nodeWasSplit) - } -} - -// Initialize a PartitionVars structure. -func InitParVars(parVars *PartitionVars, maxRects, minFill int) { - ASSERT(parVars != nil) - - parVars.count[0] = 0 - parVars.count[1] = 0 - parVars.area[0] = 0 - parVars.area[1] = 0 - parVars.total = maxRects - parVars.minFill = minFill - for index := 0; index < maxRects; index++ { - parVars.partition[index] = NOT_TAKEN - } -} - -func PickSeeds(parVars *PartitionVars) { - var seed0, seed1 int - var worst, waste float64 - var area [MAXNODES + 1]float64 - - for index := 0; index < parVars.total; index++ { - area[index] = CalcRectVolume(&parVars.branchBuf[index].rect) - } - - worst = -parVars.coverSplitArea - 1 - for indexA := 0; indexA < parVars.total-1; indexA++ { - for indexB := indexA + 1; indexB < parVars.total; indexB++ { - oneRect := CombineRect(&parVars.branchBuf[indexA].rect, &parVars.branchBuf[indexB].rect) - waste = CalcRectVolume(&oneRect) - area[indexA] - area[indexB] - if waste > worst { - worst = waste - seed0 = indexA - seed1 = indexB - } - } - } - - Classify(seed0, 0, parVars) - Classify(seed1, 1, parVars) -} - -// Put a branch in one of the groups. -func Classify(index, group int, parVars *PartitionVars) { - ASSERT(parVars != nil) - ASSERT(NOT_TAKEN == parVars.partition[index]) - - parVars.partition[index] = group - - // Calculate combined rect - if parVars.count[group] == 0 { - parVars.cover[group] = parVars.branchBuf[index].rect - } else { - parVars.cover[group] = CombineRect(&parVars.branchBuf[index].rect, &parVars.cover[group]) - } - - // Calculate volume of combined rect - parVars.area[group] = CalcRectVolume(&parVars.cover[group]) - - parVars.count[group]++ -} - -// Delete a data rectangle from an index structure. -// Pass in a pointer to a Rect, the tid of the record, ptr to ptr to root node. -// Returns 1 if record not found, 0 if success. -// RemoveRect provides for eliminating the root. -func RemoveRect(rect *Rect, id interface{}, root **Node) bool { - ASSERT(rect != nil && root != nil) - ASSERT(*root != nil) - - var reInsertList *ListNode - - if !RemoveRectRec(rect, id, *root, &reInsertList) { - // Found and deleted a data item - // Reinsert any branches from eliminated nodes - for reInsertList != nil { - tempNode := reInsertList.node - - for index := 0; index < tempNode.count; index++ { - // TODO go over this code. should I use (tempNode->m_level - 1)? - InsertRect(&tempNode.branch[index], root, tempNode.level) - } - reInsertList = reInsertList.next - } - - // Check for redundant root (not leaf, 1 child) and eliminate TODO replace - // if with while? In case there is a whole branch of redundant roots... - if (*root).count == 1 && (*root).IsInternalNode() { - tempNode := (*root).branch[0].child - - ASSERT(tempNode != nil) - *root = tempNode - } - return false - } else { - return true - } -} - -// Delete a rectangle from non-root part of an index structure. -// Called by RemoveRect. Descends tree recursively, -// merges branches on the way back up. -// Returns 1 if record not found, 0 if success. -func RemoveRectRec(rect *Rect, id interface{}, node *Node, listNode **ListNode) bool { - ASSERT(rect != nil && node != nil && listNode != nil) - ASSERT(node.level >= 0) - - if node.IsInternalNode() { // not a leaf node - for index := 0; index < node.count; index++ { - if Overlap(rect, &(node.branch[index].rect)) { - if !RemoveRectRec(rect, id, node.branch[index].child, listNode) { - if node.branch[index].child.count >= MINNODES { - // child removed, just resize parent rect - node.branch[index].rect = NodeCover(node.branch[index].child) - } else { - // child removed, not enough entries in node, eliminate node - ReInsert(node.branch[index].child, listNode) - DisconnectBranch(node, index) // Must return after this call as count has changed - } - return false - } - } - } - return true - } else { // A leaf node - for index := 0; index < node.count; index++ { - if node.branch[index].data == id { - DisconnectBranch(node, index) // Must return after this call as count has changed - return false - } - } - return true - } -} - -// Decide whether two rectangles overlap. -func Overlap(rectA, rectB *Rect) bool { - ASSERT(rectA != nil && rectB != nil) - - for index := 0; index < NUMDIMS; index++ { - if rectA.min[index] > rectB.max[index] || - rectB.min[index] > rectA.max[index] { - return false - } - } - return true -} - -// Add a node to the reinsertion list. All its branches will later -// be reinserted into the index structure. -func ReInsert(node *Node, listNode **ListNode) { - newListNode := &ListNode{} - newListNode.node = node - newListNode.next = *listNode - *listNode = newListNode -} - -// Search in an index tree or subtree for all data retangles that overlap the argument rectangle. -func Search(node *Node, rect *Rect, foundCount *int, resultCallback ResultCallback, context interface{}) bool { - ASSERT(node != nil) - ASSERT(node.level >= 0) - ASSERT(rect != nil) - - if node.IsInternalNode() { - // This is an internal node in the tree - for index := 0; index < node.count; index++ { - if Overlap(rect, &node.branch[index].rect) { - if !Search(node.branch[index].child, rect, foundCount, resultCallback, context) { - // The callback indicated to stop searching - return false - } - } - } - } else { - // This is a leaf node - for index := 0; index < node.count; index++ { - if Overlap(rect, &node.branch[index].rect) { - id := node.branch[index].data - - // NOTE: There are different ways to return results. Here's where to modify - - *foundCount++ - if !resultCallback(id, context) { - return false // Don't continue searching - } - - } - } - } - - return true // Continue searching -} diff --git a/vendor/d2/rtree.go b/vendor/d2/rtree.go index 22f3d09..b7b3f9d 100644 --- a/vendor/d2/rtree.go +++ b/vendor/d2/rtree.go @@ -56,7 +56,7 @@ const ( USE_SPHERICAL_VOLUME = true // Better split classification, may be slower on some systems ) -type ResultCallback func(dataID interface{}, context interface{}) bool +type ResultCallback func(dataID, context interface{}) bool var unitSphereVolume float64 diff --git a/vendor/d2d/rtree.go b/vendor/d2d/rtree.go deleted file mode 100644 index acf290c..0000000 --- a/vendor/d2d/rtree.go +++ /dev/null @@ -1,815 +0,0 @@ -//generated; DO NOT EDIT! - -/* - -TITLE - - R-TREES: A DYNAMIC INDEX STRUCTURE FOR SPATIAL SEARCHING - -DESCRIPTION - - A Go version of the RTree algorithm. - For more information please read the comments in rtree.go - -AUTHORS - - * 1983 Original algorithm and test code by Antonin Guttman and Michael Stonebraker, UC Berkely - * 1994 ANCI C ported from original test code by Melinda Green - melinda@superliminal.com - * 1995 Sphere volume fix for degeneracy problem submitted by Paul Brook - * 2004 Templated C++ port by Greg Douglas - * 2016 Go port by Josh Baker - -LICENSE: - - Entirely free for all uses. Enjoy! - -*/ - -// Implementation of RTree, a multidimensional bounding rectangle tree. -package rtree - -import "math" - -func Min(a, b float64) float64 { - if a < b { - return a - } - return b -} -func Max(a, b float64) float64 { - if a > b { - return a - } - return b -} -func ASSERT(condition bool) { - if _DEBUG && !condition { - panic("assertion failed") - } -} - -const ( - _DEBUG = true - NUMDIMS = 2 - MAXNODES = 8 - MINNODES = MAXNODES / 2 - USE_SPHERICAL_VOLUME = true // Better split classification, may be slower on some systems -) - -type ResultCallback func(dataID interface{}, context interface{}) bool - -var unitSphereVolume float64 - -func init() { - // Precomputed volumes of the unit spheres for the first few dimensions - unitSphereVolume = []float64{ - 0.000000, 2.000000, 3.141593, // Dimension 0,1,2 - 4.188790, 4.934802, 5.263789, // Dimension 3,4,5 - 5.167713, 4.724766, 4.058712, // Dimension 6,7,8 - 3.298509, 2.550164, 1.884104, // Dimension 9,10,11 - 1.335263, 0.910629, 0.599265, // Dimension 12,13,14 - 0.381443, 0.235331, 0.140981, // Dimension 15,16,17 - 0.082146, 0.046622, 0.025807, // Dimension 18,19,20 - }[NUMDIMS] -} - -type RTree struct { - root *Node ///< Root of tree - unitSphereVolume float64 ///< Unit sphere constant for required number of dimensions -} - -/// Minimal bounding rectangle (n-dimensional) -type Rect struct { - min [NUMDIMS]float64 ///< Min dimensions of bounding box - max [NUMDIMS]float64 ///< Max dimensions of bounding box -} - -/// May be data or may be another subtree -/// The parents level determines this. -/// If the parents level is 0, then this is data -type Branch struct { - rect Rect ///< Bounds - child *Node ///< Child node - data interface{} ///< Data Id or Ptr -} - -/// Node for each branch level -type Node struct { - count int ///< Count - level int ///< Leaf is zero, others positive - branch [MAXNODES]Branch ///< Branch -} - -func (node *Node) IsInternalNode() bool { - return (node.level > 0) // Not a leaf, but a internal node -} -func (node *Node) IsLeaf() bool { - return (node.level == 0) // A leaf, contains data -} - -/// A link list of nodes for reinsertion after a delete operation -type ListNode struct { - next *ListNode ///< Next in list - node *Node ///< Node -} - -const NOT_TAKEN = -1 // indicates that position - -/// Variables for finding a split partition -type PartitionVars struct { - partition [MAXNODES + 1]int - total int - minFill int - count [2]int - cover [2]Rect - area [2]float64 - - branchBuf [MAXNODES + 1]Branch - branchCount int - coverSplit Rect - coverSplitArea float64 -} - -func NewRTree() *RTree { - ASSERT(MAXNODES > MINNODES) - ASSERT(MINNODES > 0) - - // We only support machine word size simple data type eg. integer index or object pointer. - // Since we are storing as union with non data branch - //ASSERT(sizeof(DATATYPE) == sizeof(void*) || sizeof(DATATYPE) == sizeof(int)); - - return &RTree{ - root: &Node{}, - } -} - -/// Insert entry -/// \param a_min Min of bounding rect -/// \param a_max Max of bounding rect -/// \param a_dataId Positive Id of data. Maybe zero, but negative numbers not allowed. -func (tr *RTree) Insert(min, max [NUMDIMS]float64, dataId interface{}) { - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(min[index] <= max[index]) - } - } //_DEBUG - var branch Branch - branch.data = dataId - branch.child = nil - for axis := 0; axis < NUMDIMS; axis++ { - branch.rect.min[axis] = min[axis] - branch.rect.max[axis] = max[axis] - } - InsertRect(&branch, &tr.root, 0) -} - -/// Remove entry -/// \param a_min Min of bounding rect -/// \param a_max Max of bounding rect -/// \param a_dataId Positive Id of data. Maybe zero, but negative numbers not allowed. -func (tr *RTree) Remove(min, max [NUMDIMS]float64, dataId interface{}) { - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(min[index] <= max[index]) - } - } //_DEBUG - var rect Rect - for axis := 0; axis < NUMDIMS; axis++ { - rect.min[axis] = min[axis] - rect.max[axis] = max[axis] - } - RemoveRect(&rect, dataId, &tr.root) -} - -/// Find all within search rectangle -/// \param a_min Min of search bounding rect -/// \param a_max Max of search bounding rect -/// \param a_searchResult Search result array. Caller should set grow size. Function will reset, not append to array. -/// \param a_resultCallback Callback function to return result. Callback should return 'true' to continue searching -/// \param a_context User context to pass as parameter to a_resultCallback -/// \return Returns the number of entries found -func (tr *RTree) Search(min, max [NUMDIMS]float64, resultCallback ResultCallback, context interface{}) int { - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(min[index] <= max[index]) - } - } //_DEBUG - var rect Rect - for axis := 0; axis < NUMDIMS; axis++ { - rect.min[axis] = min[axis] - rect.max[axis] = max[axis] - } - // NOTE: May want to return search result another way, perhaps returning the number of found elements here. - - foundCount := 0 - Search(tr.root, &rect, &foundCount, resultCallback, context) - return foundCount -} - -/// Count the data elements in this container. This is slow as no internal counter is maintained. -func (tr *RTree) Count() int { - var count int - CountRec(tr.root, &count) - return count -} - -func CountRec(node *Node, count *int) { - if node.IsInternalNode() { // not a leaf node - for index := 0; index < node.count; index++ { - CountRec(node.branch[index].child, count) - } - } else { // A leaf node - *count += node.count - } -} - -/// Remove all entries from tree -func (tr *RTree) RemoveAll() { - // Delete all existing nodes - tr.root = &Node{} -} - -func InitNode(node *Node) { - node.count = 0 - node.level = -1 -} - -func InitRect(rect *Rect) { - for index := 0; index < NUMDIMS; index++ { - rect.min[index] = 0 - rect.max[index] = 0 - } -} - -// Inserts a new data rectangle into the index structure. -// Recursively descends tree, propagates splits back up. -// Returns 0 if node was not split. Old node updated. -// If node was split, returns 1 and sets the pointer pointed to by -// new_node to point to the new node. Old node updated to become one of two. -// The level argument specifies the number of steps up from the leaf -// level to insert; e.g. a data rectangle goes in at level = 0. -func InsertRectRec(branch *Branch, node *Node, newNode **Node, level int) bool { - ASSERT(node != nil && newNode != nil) - ASSERT(level >= 0 && level <= node.level) - - // recurse until we reach the correct level for the new record. data records - // will always be called with a_level == 0 (leaf) - if node.level > level { - // Still above level for insertion, go down tree recursively - var otherNode *Node - //var newBranch Branch - - // find the optimal branch for this record - index := PickBranch(&branch.rect, node) - - // recursively insert this record into the picked branch - childWasSplit := InsertRectRec(branch, node.branch[index].child, &otherNode, level) - - if !childWasSplit { - // Child was not split. Merge the bounding box of the new record with the - // existing bounding box - node.branch[index].rect = CombineRect(&branch.rect, &(node.branch[index].rect)) - return false - } else { - // Child was split. The old branches are now re-partitioned to two nodes - // so we have to re-calculate the bounding boxes of each node - node.branch[index].rect = NodeCover(node.branch[index].child) - var newBranch Branch - newBranch.child = otherNode - newBranch.rect = NodeCover(otherNode) - - // The old node is already a child of a_node. Now add the newly-created - // node to a_node as well. a_node might be split because of that. - return AddBranch(&newBranch, node, newNode) - } - } else if node.level == level { - // We have reached level for insertion. Add rect, split if necessary - return AddBranch(branch, node, newNode) - } else { - // Should never occur - ASSERT(false) - return false - } -} - -// Insert a data rectangle into an index structure. -// InsertRect provides for splitting the root; -// returns 1 if root was split, 0 if it was not. -// The level argument specifies the number of steps up from the leaf -// level to insert; e.g. a data rectangle goes in at level = 0. -// InsertRect2 does the recursion. -// -func InsertRect(branch *Branch, root **Node, level int) bool { - ASSERT(root != nil) - ASSERT(level >= 0 && level <= (*root).level) - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(branch.rect.min[index] <= branch.rect.max[index]) - } - } //_DEBUG - - var newNode *Node - - if InsertRectRec(branch, *root, &newNode, level) { // Root split - - // Grow tree taller and new root - newRoot := &Node{} - newRoot.level = (*root).level + 1 - - var newBranch Branch - - // add old root node as a child of the new root - newBranch.rect = NodeCover(*root) - newBranch.child = *root - AddBranch(&newBranch, newRoot, nil) - - // add the split node as a child of the new root - newBranch.rect = NodeCover(newNode) - newBranch.child = newNode - AddBranch(&newBranch, newRoot, nil) - - // set the new root as the root node - *root = newRoot - - return true - } - - return false -} - -// Find the smallest rectangle that includes all rectangles in branches of a node. -func NodeCover(node *Node) Rect { - ASSERT(node != nil) - - rect := node.branch[0].rect - for index := 1; index < node.count; index++ { - rect = CombineRect(&rect, &(node.branch[index].rect)) - } - - return rect -} - -// Add a branch to a node. Split the node if necessary. -// Returns 0 if node not split. Old node updated. -// Returns 1 if node split, sets *new_node to address of new node. -// Old node updated, becomes one of two. -func AddBranch(branch *Branch, node *Node, newNode **Node) bool { - ASSERT(branch != nil) - ASSERT(node != nil) - - if node.count < MAXNODES { // Split won't be necessary - - node.branch[node.count] = *branch - node.count++ - - return false - } else { - ASSERT(newNode != nil) - - SplitNode(node, branch, newNode) - return true - } -} - -// Disconnect a dependent node. -// Caller must return (or stop using iteration index) after this as count has changed -func DisconnectBranch(node *Node, index int) { - ASSERT(node != nil && (index >= 0) && (index < MAXNODES)) - ASSERT(node.count > 0) - - // Remove element by swapping with the last element to prevent gaps in array - node.branch[index] = node.branch[node.count-1] - - node.count-- -} - -// Pick a branch. Pick the one that will need the smallest increase -// in area to accomodate the new rectangle. This will result in the -// least total area for the covering rectangles in the current node. -// In case of a tie, pick the one which was smaller before, to get -// the best resolution when searching. -func PickBranch(rect *Rect, node *Node) int { - ASSERT(rect != nil && node != nil) - - var firstTime bool = true - var increase float64 - var bestIncr float64 = -1 - var area float64 - var bestArea float64 - var best int - var tempRect Rect - - for index := 0; index < node.count; index++ { - curRect := &node.branch[index].rect - area = CalcRectVolume(curRect) - tempRect = CombineRect(rect, curRect) - increase = CalcRectVolume(&tempRect) - area - if (increase < bestIncr) || firstTime { - best = index - bestArea = area - bestIncr = increase - firstTime = false - } else if (increase == bestIncr) && (area < bestArea) { - best = index - bestArea = area - bestIncr = increase - } - } - return best -} - -// Combine two rectangles into larger one containing both -func CombineRect(rectA, rectB *Rect) Rect { - ASSERT(rectA != nil && rectB != nil) - - var newRect Rect - - for index := 0; index < NUMDIMS; index++ { - newRect.min[index] = Min(rectA.min[index], rectB.min[index]) - newRect.max[index] = Max(rectA.max[index], rectB.max[index]) - } - - return newRect -} - -// Split a node. -// Divides the nodes branches and the extra one between two nodes. -// Old node is one of the new ones, and one really new one is created. -// Tries more than one method for choosing a partition, uses best result. -func SplitNode(node *Node, branch *Branch, newNode **Node) { - ASSERT(node != nil) - ASSERT(branch != nil) - - // Could just use local here, but member or external is faster since it is reused - var localVars PartitionVars - parVars := &localVars - - // Load all the branches into a buffer, initialize old node - GetBranches(node, branch, parVars) - - // Find partition - ChoosePartition(parVars, MINNODES) - - // Create a new node to hold (about) half of the branches - *newNode = &Node{} - (*newNode).level = node.level - - // Put branches from buffer into 2 nodes according to the chosen partition - node.count = 0 - LoadNodes(node, *newNode, parVars) - - ASSERT((node.count + (*newNode).count) == parVars.total) -} - -// Calculate the n-dimensional volume of a rectangle -func RectVolume(rect *Rect) float64 { - ASSERT(rect != nil) - - var volume float64 = 1 - - for index := 0; index < NUMDIMS; index++ { - volume *= rect.max[index] - rect.min[index] - } - - ASSERT(volume >= 0) - - return volume -} - -// The exact volume of the bounding sphere for the given Rect -func RectSphericalVolume(rect *Rect) float64 { - ASSERT(rect != nil) - - var sumOfSquares float64 = 0 - var radius float64 - - for index := 0; index < NUMDIMS; index++ { - halfExtent := (rect.max[index] - rect.min[index]) * 0.5 - sumOfSquares += halfExtent * halfExtent - } - - radius = math.Sqrt(sumOfSquares) - - // Pow maybe slow, so test for common dims like 2,3 and just use x*x, x*x*x. - if NUMDIMS == 4 { - return (radius * radius * radius * radius * unitSphereVolume) - } else if NUMDIMS == 3 { - return (radius * radius * radius * unitSphereVolume) - } else if NUMDIMS == 2 { - return (radius * radius * unitSphereVolume) - } else { - return (math.Pow(radius, NUMDIMS) * unitSphereVolume) - } -} - -// Use one of the methods to calculate retangle volume -func CalcRectVolume(rect *Rect) float64 { - if USE_SPHERICAL_VOLUME { - return RectSphericalVolume(rect) // Slower but helps certain merge cases - } else { // RTREE_USE_SPHERICAL_VOLUME - return RectVolume(rect) // Faster but can cause poor merges - } // RTREE_USE_SPHERICAL_VOLUME -} - -// Load branch buffer with branches from full node plus the extra branch. -func GetBranches(node *Node, branch *Branch, parVars *PartitionVars) { - ASSERT(node != nil) - ASSERT(branch != nil) - - ASSERT(node.count == MAXNODES) - - // Load the branch buffer - for index := 0; index < MAXNODES; index++ { - parVars.branchBuf[index] = node.branch[index] - } - parVars.branchBuf[MAXNODES] = *branch - parVars.branchCount = MAXNODES + 1 - - // Calculate rect containing all in the set - parVars.coverSplit = parVars.branchBuf[0].rect - for index := 1; index < MAXNODES+1; index++ { - parVars.coverSplit = CombineRect(&parVars.coverSplit, &parVars.branchBuf[index].rect) - } - parVars.coverSplitArea = CalcRectVolume(&parVars.coverSplit) -} - -// Method #0 for choosing a partition: -// As the seeds for the two groups, pick the two rects that would waste the -// most area if covered by a single rectangle, i.e. evidently the worst pair -// to have in the same group. -// Of the remaining, one at a time is chosen to be put in one of the two groups. -// The one chosen is the one with the greatest difference in area expansion -// depending on which group - the rect most strongly attracted to one group -// and repelled from the other. -// If one group gets too full (more would force other group to violate min -// fill requirement) then other group gets the rest. -// These last are the ones that can go in either group most easily. -func ChoosePartition(parVars *PartitionVars, minFill int) { - ASSERT(parVars != nil) - - var biggestDiff float64 - var group, chosen, betterGroup int - - InitParVars(parVars, parVars.branchCount, minFill) - PickSeeds(parVars) - - for ((parVars.count[0] + parVars.count[1]) < parVars.total) && - (parVars.count[0] < (parVars.total - parVars.minFill)) && - (parVars.count[1] < (parVars.total - parVars.minFill)) { - biggestDiff = -1 - for index := 0; index < parVars.total; index++ { - if NOT_TAKEN == parVars.partition[index] { - curRect := &parVars.branchBuf[index].rect - rect0 := CombineRect(curRect, &parVars.cover[0]) - rect1 := CombineRect(curRect, &parVars.cover[1]) - growth0 := CalcRectVolume(&rect0) - parVars.area[0] - growth1 := CalcRectVolume(&rect1) - parVars.area[1] - diff := growth1 - growth0 - if diff >= 0 { - group = 0 - } else { - group = 1 - diff = -diff - } - - if diff > biggestDiff { - biggestDiff = diff - chosen = index - betterGroup = group - } else if (diff == biggestDiff) && (parVars.count[group] < parVars.count[betterGroup]) { - chosen = index - betterGroup = group - } - } - } - Classify(chosen, betterGroup, parVars) - } - - // If one group too full, put remaining rects in the other - if (parVars.count[0] + parVars.count[1]) < parVars.total { - if parVars.count[0] >= parVars.total-parVars.minFill { - group = 1 - } else { - group = 0 - } - for index := 0; index < parVars.total; index++ { - if NOT_TAKEN == parVars.partition[index] { - Classify(index, group, parVars) - } - } - } - - ASSERT((parVars.count[0] + parVars.count[1]) == parVars.total) - ASSERT((parVars.count[0] >= parVars.minFill) && - (parVars.count[1] >= parVars.minFill)) -} - -// Copy branches from the buffer into two nodes according to the partition. -func LoadNodes(nodeA, nodeB *Node, parVars *PartitionVars) { - ASSERT(nodeA != nil) - ASSERT(nodeB != nil) - ASSERT(parVars != nil) - - for index := 0; index < parVars.total; index++ { - ASSERT(parVars.partition[index] == 0 || parVars.partition[index] == 1) - - targetNodeIndex := parVars.partition[index] - targetNodes := []*Node{nodeA, nodeB} - - // It is assured that AddBranch here will not cause a node split. - nodeWasSplit := AddBranch(&parVars.branchBuf[index], targetNodes[targetNodeIndex], nil) - ASSERT(!nodeWasSplit) - } -} - -// Initialize a PartitionVars structure. -func InitParVars(parVars *PartitionVars, maxRects, minFill int) { - ASSERT(parVars != nil) - - parVars.count[0] = 0 - parVars.count[1] = 0 - parVars.area[0] = 0 - parVars.area[1] = 0 - parVars.total = maxRects - parVars.minFill = minFill - for index := 0; index < maxRects; index++ { - parVars.partition[index] = NOT_TAKEN - } -} - -func PickSeeds(parVars *PartitionVars) { - var seed0, seed1 int - var worst, waste float64 - var area [MAXNODES + 1]float64 - - for index := 0; index < parVars.total; index++ { - area[index] = CalcRectVolume(&parVars.branchBuf[index].rect) - } - - worst = -parVars.coverSplitArea - 1 - for indexA := 0; indexA < parVars.total-1; indexA++ { - for indexB := indexA + 1; indexB < parVars.total; indexB++ { - oneRect := CombineRect(&parVars.branchBuf[indexA].rect, &parVars.branchBuf[indexB].rect) - waste = CalcRectVolume(&oneRect) - area[indexA] - area[indexB] - if waste > worst { - worst = waste - seed0 = indexA - seed1 = indexB - } - } - } - - Classify(seed0, 0, parVars) - Classify(seed1, 1, parVars) -} - -// Put a branch in one of the groups. -func Classify(index, group int, parVars *PartitionVars) { - ASSERT(parVars != nil) - ASSERT(NOT_TAKEN == parVars.partition[index]) - - parVars.partition[index] = group - - // Calculate combined rect - if parVars.count[group] == 0 { - parVars.cover[group] = parVars.branchBuf[index].rect - } else { - parVars.cover[group] = CombineRect(&parVars.branchBuf[index].rect, &parVars.cover[group]) - } - - // Calculate volume of combined rect - parVars.area[group] = CalcRectVolume(&parVars.cover[group]) - - parVars.count[group]++ -} - -// Delete a data rectangle from an index structure. -// Pass in a pointer to a Rect, the tid of the record, ptr to ptr to root node. -// Returns 1 if record not found, 0 if success. -// RemoveRect provides for eliminating the root. -func RemoveRect(rect *Rect, id interface{}, root **Node) bool { - ASSERT(rect != nil && root != nil) - ASSERT(*root != nil) - - var reInsertList *ListNode - - if !RemoveRectRec(rect, id, *root, &reInsertList) { - // Found and deleted a data item - // Reinsert any branches from eliminated nodes - for reInsertList != nil { - tempNode := reInsertList.node - - for index := 0; index < tempNode.count; index++ { - // TODO go over this code. should I use (tempNode->m_level - 1)? - InsertRect(&tempNode.branch[index], root, tempNode.level) - } - reInsertList = reInsertList.next - } - - // Check for redundant root (not leaf, 1 child) and eliminate TODO replace - // if with while? In case there is a whole branch of redundant roots... - if (*root).count == 1 && (*root).IsInternalNode() { - tempNode := (*root).branch[0].child - - ASSERT(tempNode != nil) - *root = tempNode - } - return false - } else { - return true - } -} - -// Delete a rectangle from non-root part of an index structure. -// Called by RemoveRect. Descends tree recursively, -// merges branches on the way back up. -// Returns 1 if record not found, 0 if success. -func RemoveRectRec(rect *Rect, id interface{}, node *Node, listNode **ListNode) bool { - ASSERT(rect != nil && node != nil && listNode != nil) - ASSERT(node.level >= 0) - - if node.IsInternalNode() { // not a leaf node - for index := 0; index < node.count; index++ { - if Overlap(rect, &(node.branch[index].rect)) { - if !RemoveRectRec(rect, id, node.branch[index].child, listNode) { - if node.branch[index].child.count >= MINNODES { - // child removed, just resize parent rect - node.branch[index].rect = NodeCover(node.branch[index].child) - } else { - // child removed, not enough entries in node, eliminate node - ReInsert(node.branch[index].child, listNode) - DisconnectBranch(node, index) // Must return after this call as count has changed - } - return false - } - } - } - return true - } else { // A leaf node - for index := 0; index < node.count; index++ { - if node.branch[index].data == id { - DisconnectBranch(node, index) // Must return after this call as count has changed - return false - } - } - return true - } -} - -// Decide whether two rectangles overlap. -func Overlap(rectA, rectB *Rect) bool { - ASSERT(rectA != nil && rectB != nil) - - for index := 0; index < NUMDIMS; index++ { - if rectA.min[index] > rectB.max[index] || - rectB.min[index] > rectA.max[index] { - return false - } - } - return true -} - -// Add a node to the reinsertion list. All its branches will later -// be reinserted into the index structure. -func ReInsert(node *Node, listNode **ListNode) { - newListNode := &ListNode{} - newListNode.node = node - newListNode.next = *listNode - *listNode = newListNode -} - -// Search in an index tree or subtree for all data retangles that overlap the argument rectangle. -func Search(node *Node, rect *Rect, foundCount *int, resultCallback ResultCallback, context interface{}) bool { - ASSERT(node != nil) - ASSERT(node.level >= 0) - ASSERT(rect != nil) - - if node.IsInternalNode() { - // This is an internal node in the tree - for index := 0; index < node.count; index++ { - if Overlap(rect, &node.branch[index].rect) { - if !Search(node.branch[index].child, rect, foundCount, resultCallback, context) { - // The callback indicated to stop searching - return false - } - } - } - } else { - // This is a leaf node - for index := 0; index < node.count; index++ { - if Overlap(rect, &node.branch[index].rect) { - id := node.branch[index].data - - // NOTE: There are different ways to return results. Here's where to modify - - *foundCount++ - if !resultCallback(id, context) { - return false // Don't continue searching - } - - } - } - } - - return true // Continue searching -} diff --git a/vendor/d3/rtree.go b/vendor/d3/rtree.go index 0e95911..e939c36 100644 --- a/vendor/d3/rtree.go +++ b/vendor/d3/rtree.go @@ -56,7 +56,7 @@ const ( USE_SPHERICAL_VOLUME = true // Better split classification, may be slower on some systems ) -type ResultCallback func(dataID interface{}, context interface{}) bool +type ResultCallback func(dataID, context interface{}) bool var unitSphereVolume float64 diff --git a/vendor/d3d/rtree.go b/vendor/d3d/rtree.go deleted file mode 100644 index e94f9f0..0000000 --- a/vendor/d3d/rtree.go +++ /dev/null @@ -1,815 +0,0 @@ -//generated; DO NOT EDIT! - -/* - -TITLE - - R-TREES: A DYNAMIC INDEX STRUCTURE FOR SPATIAL SEARCHING - -DESCRIPTION - - A Go version of the RTree algorithm. - For more information please read the comments in rtree.go - -AUTHORS - - * 1983 Original algorithm and test code by Antonin Guttman and Michael Stonebraker, UC Berkely - * 1994 ANCI C ported from original test code by Melinda Green - melinda@superliminal.com - * 1995 Sphere volume fix for degeneracy problem submitted by Paul Brook - * 2004 Templated C++ port by Greg Douglas - * 2016 Go port by Josh Baker - -LICENSE: - - Entirely free for all uses. Enjoy! - -*/ - -// Implementation of RTree, a multidimensional bounding rectangle tree. -package rtree - -import "math" - -func Min(a, b float64) float64 { - if a < b { - return a - } - return b -} -func Max(a, b float64) float64 { - if a > b { - return a - } - return b -} -func ASSERT(condition bool) { - if _DEBUG && !condition { - panic("assertion failed") - } -} - -const ( - _DEBUG = true - NUMDIMS = 3 - MAXNODES = 8 - MINNODES = MAXNODES / 2 - USE_SPHERICAL_VOLUME = true // Better split classification, may be slower on some systems -) - -type ResultCallback func(dataID interface{}, context interface{}) bool - -var unitSphereVolume float64 - -func init() { - // Precomputed volumes of the unit spheres for the first few dimensions - unitSphereVolume = []float64{ - 0.000000, 2.000000, 3.141593, // Dimension 0,1,2 - 4.188790, 4.934802, 5.263789, // Dimension 3,4,5 - 5.167713, 4.724766, 4.058712, // Dimension 6,7,8 - 3.298509, 2.550164, 1.884104, // Dimension 9,10,11 - 1.335263, 0.910629, 0.599265, // Dimension 12,13,14 - 0.381443, 0.235331, 0.140981, // Dimension 15,16,17 - 0.082146, 0.046622, 0.025807, // Dimension 18,19,20 - }[NUMDIMS] -} - -type RTree struct { - root *Node ///< Root of tree - unitSphereVolume float64 ///< Unit sphere constant for required number of dimensions -} - -/// Minimal bounding rectangle (n-dimensional) -type Rect struct { - min [NUMDIMS]float64 ///< Min dimensions of bounding box - max [NUMDIMS]float64 ///< Max dimensions of bounding box -} - -/// May be data or may be another subtree -/// The parents level determines this. -/// If the parents level is 0, then this is data -type Branch struct { - rect Rect ///< Bounds - child *Node ///< Child node - data interface{} ///< Data Id or Ptr -} - -/// Node for each branch level -type Node struct { - count int ///< Count - level int ///< Leaf is zero, others positive - branch [MAXNODES]Branch ///< Branch -} - -func (node *Node) IsInternalNode() bool { - return (node.level > 0) // Not a leaf, but a internal node -} -func (node *Node) IsLeaf() bool { - return (node.level == 0) // A leaf, contains data -} - -/// A link list of nodes for reinsertion after a delete operation -type ListNode struct { - next *ListNode ///< Next in list - node *Node ///< Node -} - -const NOT_TAKEN = -1 // indicates that position - -/// Variables for finding a split partition -type PartitionVars struct { - partition [MAXNODES + 1]int - total int - minFill int - count [2]int - cover [2]Rect - area [2]float64 - - branchBuf [MAXNODES + 1]Branch - branchCount int - coverSplit Rect - coverSplitArea float64 -} - -func NewRTree() *RTree { - ASSERT(MAXNODES > MINNODES) - ASSERT(MINNODES > 0) - - // We only support machine word size simple data type eg. integer index or object pointer. - // Since we are storing as union with non data branch - //ASSERT(sizeof(DATATYPE) == sizeof(void*) || sizeof(DATATYPE) == sizeof(int)); - - return &RTree{ - root: &Node{}, - } -} - -/// Insert entry -/// \param a_min Min of bounding rect -/// \param a_max Max of bounding rect -/// \param a_dataId Positive Id of data. Maybe zero, but negative numbers not allowed. -func (tr *RTree) Insert(min, max [NUMDIMS]float64, dataId interface{}) { - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(min[index] <= max[index]) - } - } //_DEBUG - var branch Branch - branch.data = dataId - branch.child = nil - for axis := 0; axis < NUMDIMS; axis++ { - branch.rect.min[axis] = min[axis] - branch.rect.max[axis] = max[axis] - } - InsertRect(&branch, &tr.root, 0) -} - -/// Remove entry -/// \param a_min Min of bounding rect -/// \param a_max Max of bounding rect -/// \param a_dataId Positive Id of data. Maybe zero, but negative numbers not allowed. -func (tr *RTree) Remove(min, max [NUMDIMS]float64, dataId interface{}) { - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(min[index] <= max[index]) - } - } //_DEBUG - var rect Rect - for axis := 0; axis < NUMDIMS; axis++ { - rect.min[axis] = min[axis] - rect.max[axis] = max[axis] - } - RemoveRect(&rect, dataId, &tr.root) -} - -/// Find all within search rectangle -/// \param a_min Min of search bounding rect -/// \param a_max Max of search bounding rect -/// \param a_searchResult Search result array. Caller should set grow size. Function will reset, not append to array. -/// \param a_resultCallback Callback function to return result. Callback should return 'true' to continue searching -/// \param a_context User context to pass as parameter to a_resultCallback -/// \return Returns the number of entries found -func (tr *RTree) Search(min, max [NUMDIMS]float64, resultCallback ResultCallback, context interface{}) int { - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(min[index] <= max[index]) - } - } //_DEBUG - var rect Rect - for axis := 0; axis < NUMDIMS; axis++ { - rect.min[axis] = min[axis] - rect.max[axis] = max[axis] - } - // NOTE: May want to return search result another way, perhaps returning the number of found elements here. - - foundCount := 0 - Search(tr.root, &rect, &foundCount, resultCallback, context) - return foundCount -} - -/// Count the data elements in this container. This is slow as no internal counter is maintained. -func (tr *RTree) Count() int { - var count int - CountRec(tr.root, &count) - return count -} - -func CountRec(node *Node, count *int) { - if node.IsInternalNode() { // not a leaf node - for index := 0; index < node.count; index++ { - CountRec(node.branch[index].child, count) - } - } else { // A leaf node - *count += node.count - } -} - -/// Remove all entries from tree -func (tr *RTree) RemoveAll() { - // Delete all existing nodes - tr.root = &Node{} -} - -func InitNode(node *Node) { - node.count = 0 - node.level = -1 -} - -func InitRect(rect *Rect) { - for index := 0; index < NUMDIMS; index++ { - rect.min[index] = 0 - rect.max[index] = 0 - } -} - -// Inserts a new data rectangle into the index structure. -// Recursively descends tree, propagates splits back up. -// Returns 0 if node was not split. Old node updated. -// If node was split, returns 1 and sets the pointer pointed to by -// new_node to point to the new node. Old node updated to become one of two. -// The level argument specifies the number of steps up from the leaf -// level to insert; e.g. a data rectangle goes in at level = 0. -func InsertRectRec(branch *Branch, node *Node, newNode **Node, level int) bool { - ASSERT(node != nil && newNode != nil) - ASSERT(level >= 0 && level <= node.level) - - // recurse until we reach the correct level for the new record. data records - // will always be called with a_level == 0 (leaf) - if node.level > level { - // Still above level for insertion, go down tree recursively - var otherNode *Node - //var newBranch Branch - - // find the optimal branch for this record - index := PickBranch(&branch.rect, node) - - // recursively insert this record into the picked branch - childWasSplit := InsertRectRec(branch, node.branch[index].child, &otherNode, level) - - if !childWasSplit { - // Child was not split. Merge the bounding box of the new record with the - // existing bounding box - node.branch[index].rect = CombineRect(&branch.rect, &(node.branch[index].rect)) - return false - } else { - // Child was split. The old branches are now re-partitioned to two nodes - // so we have to re-calculate the bounding boxes of each node - node.branch[index].rect = NodeCover(node.branch[index].child) - var newBranch Branch - newBranch.child = otherNode - newBranch.rect = NodeCover(otherNode) - - // The old node is already a child of a_node. Now add the newly-created - // node to a_node as well. a_node might be split because of that. - return AddBranch(&newBranch, node, newNode) - } - } else if node.level == level { - // We have reached level for insertion. Add rect, split if necessary - return AddBranch(branch, node, newNode) - } else { - // Should never occur - ASSERT(false) - return false - } -} - -// Insert a data rectangle into an index structure. -// InsertRect provides for splitting the root; -// returns 1 if root was split, 0 if it was not. -// The level argument specifies the number of steps up from the leaf -// level to insert; e.g. a data rectangle goes in at level = 0. -// InsertRect2 does the recursion. -// -func InsertRect(branch *Branch, root **Node, level int) bool { - ASSERT(root != nil) - ASSERT(level >= 0 && level <= (*root).level) - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(branch.rect.min[index] <= branch.rect.max[index]) - } - } //_DEBUG - - var newNode *Node - - if InsertRectRec(branch, *root, &newNode, level) { // Root split - - // Grow tree taller and new root - newRoot := &Node{} - newRoot.level = (*root).level + 1 - - var newBranch Branch - - // add old root node as a child of the new root - newBranch.rect = NodeCover(*root) - newBranch.child = *root - AddBranch(&newBranch, newRoot, nil) - - // add the split node as a child of the new root - newBranch.rect = NodeCover(newNode) - newBranch.child = newNode - AddBranch(&newBranch, newRoot, nil) - - // set the new root as the root node - *root = newRoot - - return true - } - - return false -} - -// Find the smallest rectangle that includes all rectangles in branches of a node. -func NodeCover(node *Node) Rect { - ASSERT(node != nil) - - rect := node.branch[0].rect - for index := 1; index < node.count; index++ { - rect = CombineRect(&rect, &(node.branch[index].rect)) - } - - return rect -} - -// Add a branch to a node. Split the node if necessary. -// Returns 0 if node not split. Old node updated. -// Returns 1 if node split, sets *new_node to address of new node. -// Old node updated, becomes one of two. -func AddBranch(branch *Branch, node *Node, newNode **Node) bool { - ASSERT(branch != nil) - ASSERT(node != nil) - - if node.count < MAXNODES { // Split won't be necessary - - node.branch[node.count] = *branch - node.count++ - - return false - } else { - ASSERT(newNode != nil) - - SplitNode(node, branch, newNode) - return true - } -} - -// Disconnect a dependent node. -// Caller must return (or stop using iteration index) after this as count has changed -func DisconnectBranch(node *Node, index int) { - ASSERT(node != nil && (index >= 0) && (index < MAXNODES)) - ASSERT(node.count > 0) - - // Remove element by swapping with the last element to prevent gaps in array - node.branch[index] = node.branch[node.count-1] - - node.count-- -} - -// Pick a branch. Pick the one that will need the smallest increase -// in area to accomodate the new rectangle. This will result in the -// least total area for the covering rectangles in the current node. -// In case of a tie, pick the one which was smaller before, to get -// the best resolution when searching. -func PickBranch(rect *Rect, node *Node) int { - ASSERT(rect != nil && node != nil) - - var firstTime bool = true - var increase float64 - var bestIncr float64 = -1 - var area float64 - var bestArea float64 - var best int - var tempRect Rect - - for index := 0; index < node.count; index++ { - curRect := &node.branch[index].rect - area = CalcRectVolume(curRect) - tempRect = CombineRect(rect, curRect) - increase = CalcRectVolume(&tempRect) - area - if (increase < bestIncr) || firstTime { - best = index - bestArea = area - bestIncr = increase - firstTime = false - } else if (increase == bestIncr) && (area < bestArea) { - best = index - bestArea = area - bestIncr = increase - } - } - return best -} - -// Combine two rectangles into larger one containing both -func CombineRect(rectA, rectB *Rect) Rect { - ASSERT(rectA != nil && rectB != nil) - - var newRect Rect - - for index := 0; index < NUMDIMS; index++ { - newRect.min[index] = Min(rectA.min[index], rectB.min[index]) - newRect.max[index] = Max(rectA.max[index], rectB.max[index]) - } - - return newRect -} - -// Split a node. -// Divides the nodes branches and the extra one between two nodes. -// Old node is one of the new ones, and one really new one is created. -// Tries more than one method for choosing a partition, uses best result. -func SplitNode(node *Node, branch *Branch, newNode **Node) { - ASSERT(node != nil) - ASSERT(branch != nil) - - // Could just use local here, but member or external is faster since it is reused - var localVars PartitionVars - parVars := &localVars - - // Load all the branches into a buffer, initialize old node - GetBranches(node, branch, parVars) - - // Find partition - ChoosePartition(parVars, MINNODES) - - // Create a new node to hold (about) half of the branches - *newNode = &Node{} - (*newNode).level = node.level - - // Put branches from buffer into 2 nodes according to the chosen partition - node.count = 0 - LoadNodes(node, *newNode, parVars) - - ASSERT((node.count + (*newNode).count) == parVars.total) -} - -// Calculate the n-dimensional volume of a rectangle -func RectVolume(rect *Rect) float64 { - ASSERT(rect != nil) - - var volume float64 = 1 - - for index := 0; index < NUMDIMS; index++ { - volume *= rect.max[index] - rect.min[index] - } - - ASSERT(volume >= 0) - - return volume -} - -// The exact volume of the bounding sphere for the given Rect -func RectSphericalVolume(rect *Rect) float64 { - ASSERT(rect != nil) - - var sumOfSquares float64 = 0 - var radius float64 - - for index := 0; index < NUMDIMS; index++ { - halfExtent := (rect.max[index] - rect.min[index]) * 0.5 - sumOfSquares += halfExtent * halfExtent - } - - radius = math.Sqrt(sumOfSquares) - - // Pow maybe slow, so test for common dims like 2,3 and just use x*x, x*x*x. - if NUMDIMS == 4 { - return (radius * radius * radius * radius * unitSphereVolume) - } else if NUMDIMS == 3 { - return (radius * radius * radius * unitSphereVolume) - } else if NUMDIMS == 2 { - return (radius * radius * unitSphereVolume) - } else { - return (math.Pow(radius, NUMDIMS) * unitSphereVolume) - } -} - -// Use one of the methods to calculate retangle volume -func CalcRectVolume(rect *Rect) float64 { - if USE_SPHERICAL_VOLUME { - return RectSphericalVolume(rect) // Slower but helps certain merge cases - } else { // RTREE_USE_SPHERICAL_VOLUME - return RectVolume(rect) // Faster but can cause poor merges - } // RTREE_USE_SPHERICAL_VOLUME -} - -// Load branch buffer with branches from full node plus the extra branch. -func GetBranches(node *Node, branch *Branch, parVars *PartitionVars) { - ASSERT(node != nil) - ASSERT(branch != nil) - - ASSERT(node.count == MAXNODES) - - // Load the branch buffer - for index := 0; index < MAXNODES; index++ { - parVars.branchBuf[index] = node.branch[index] - } - parVars.branchBuf[MAXNODES] = *branch - parVars.branchCount = MAXNODES + 1 - - // Calculate rect containing all in the set - parVars.coverSplit = parVars.branchBuf[0].rect - for index := 1; index < MAXNODES+1; index++ { - parVars.coverSplit = CombineRect(&parVars.coverSplit, &parVars.branchBuf[index].rect) - } - parVars.coverSplitArea = CalcRectVolume(&parVars.coverSplit) -} - -// Method #0 for choosing a partition: -// As the seeds for the two groups, pick the two rects that would waste the -// most area if covered by a single rectangle, i.e. evidently the worst pair -// to have in the same group. -// Of the remaining, one at a time is chosen to be put in one of the two groups. -// The one chosen is the one with the greatest difference in area expansion -// depending on which group - the rect most strongly attracted to one group -// and repelled from the other. -// If one group gets too full (more would force other group to violate min -// fill requirement) then other group gets the rest. -// These last are the ones that can go in either group most easily. -func ChoosePartition(parVars *PartitionVars, minFill int) { - ASSERT(parVars != nil) - - var biggestDiff float64 - var group, chosen, betterGroup int - - InitParVars(parVars, parVars.branchCount, minFill) - PickSeeds(parVars) - - for ((parVars.count[0] + parVars.count[1]) < parVars.total) && - (parVars.count[0] < (parVars.total - parVars.minFill)) && - (parVars.count[1] < (parVars.total - parVars.minFill)) { - biggestDiff = -1 - for index := 0; index < parVars.total; index++ { - if NOT_TAKEN == parVars.partition[index] { - curRect := &parVars.branchBuf[index].rect - rect0 := CombineRect(curRect, &parVars.cover[0]) - rect1 := CombineRect(curRect, &parVars.cover[1]) - growth0 := CalcRectVolume(&rect0) - parVars.area[0] - growth1 := CalcRectVolume(&rect1) - parVars.area[1] - diff := growth1 - growth0 - if diff >= 0 { - group = 0 - } else { - group = 1 - diff = -diff - } - - if diff > biggestDiff { - biggestDiff = diff - chosen = index - betterGroup = group - } else if (diff == biggestDiff) && (parVars.count[group] < parVars.count[betterGroup]) { - chosen = index - betterGroup = group - } - } - } - Classify(chosen, betterGroup, parVars) - } - - // If one group too full, put remaining rects in the other - if (parVars.count[0] + parVars.count[1]) < parVars.total { - if parVars.count[0] >= parVars.total-parVars.minFill { - group = 1 - } else { - group = 0 - } - for index := 0; index < parVars.total; index++ { - if NOT_TAKEN == parVars.partition[index] { - Classify(index, group, parVars) - } - } - } - - ASSERT((parVars.count[0] + parVars.count[1]) == parVars.total) - ASSERT((parVars.count[0] >= parVars.minFill) && - (parVars.count[1] >= parVars.minFill)) -} - -// Copy branches from the buffer into two nodes according to the partition. -func LoadNodes(nodeA, nodeB *Node, parVars *PartitionVars) { - ASSERT(nodeA != nil) - ASSERT(nodeB != nil) - ASSERT(parVars != nil) - - for index := 0; index < parVars.total; index++ { - ASSERT(parVars.partition[index] == 0 || parVars.partition[index] == 1) - - targetNodeIndex := parVars.partition[index] - targetNodes := []*Node{nodeA, nodeB} - - // It is assured that AddBranch here will not cause a node split. - nodeWasSplit := AddBranch(&parVars.branchBuf[index], targetNodes[targetNodeIndex], nil) - ASSERT(!nodeWasSplit) - } -} - -// Initialize a PartitionVars structure. -func InitParVars(parVars *PartitionVars, maxRects, minFill int) { - ASSERT(parVars != nil) - - parVars.count[0] = 0 - parVars.count[1] = 0 - parVars.area[0] = 0 - parVars.area[1] = 0 - parVars.total = maxRects - parVars.minFill = minFill - for index := 0; index < maxRects; index++ { - parVars.partition[index] = NOT_TAKEN - } -} - -func PickSeeds(parVars *PartitionVars) { - var seed0, seed1 int - var worst, waste float64 - var area [MAXNODES + 1]float64 - - for index := 0; index < parVars.total; index++ { - area[index] = CalcRectVolume(&parVars.branchBuf[index].rect) - } - - worst = -parVars.coverSplitArea - 1 - for indexA := 0; indexA < parVars.total-1; indexA++ { - for indexB := indexA + 1; indexB < parVars.total; indexB++ { - oneRect := CombineRect(&parVars.branchBuf[indexA].rect, &parVars.branchBuf[indexB].rect) - waste = CalcRectVolume(&oneRect) - area[indexA] - area[indexB] - if waste > worst { - worst = waste - seed0 = indexA - seed1 = indexB - } - } - } - - Classify(seed0, 0, parVars) - Classify(seed1, 1, parVars) -} - -// Put a branch in one of the groups. -func Classify(index, group int, parVars *PartitionVars) { - ASSERT(parVars != nil) - ASSERT(NOT_TAKEN == parVars.partition[index]) - - parVars.partition[index] = group - - // Calculate combined rect - if parVars.count[group] == 0 { - parVars.cover[group] = parVars.branchBuf[index].rect - } else { - parVars.cover[group] = CombineRect(&parVars.branchBuf[index].rect, &parVars.cover[group]) - } - - // Calculate volume of combined rect - parVars.area[group] = CalcRectVolume(&parVars.cover[group]) - - parVars.count[group]++ -} - -// Delete a data rectangle from an index structure. -// Pass in a pointer to a Rect, the tid of the record, ptr to ptr to root node. -// Returns 1 if record not found, 0 if success. -// RemoveRect provides for eliminating the root. -func RemoveRect(rect *Rect, id interface{}, root **Node) bool { - ASSERT(rect != nil && root != nil) - ASSERT(*root != nil) - - var reInsertList *ListNode - - if !RemoveRectRec(rect, id, *root, &reInsertList) { - // Found and deleted a data item - // Reinsert any branches from eliminated nodes - for reInsertList != nil { - tempNode := reInsertList.node - - for index := 0; index < tempNode.count; index++ { - // TODO go over this code. should I use (tempNode->m_level - 1)? - InsertRect(&tempNode.branch[index], root, tempNode.level) - } - reInsertList = reInsertList.next - } - - // Check for redundant root (not leaf, 1 child) and eliminate TODO replace - // if with while? In case there is a whole branch of redundant roots... - if (*root).count == 1 && (*root).IsInternalNode() { - tempNode := (*root).branch[0].child - - ASSERT(tempNode != nil) - *root = tempNode - } - return false - } else { - return true - } -} - -// Delete a rectangle from non-root part of an index structure. -// Called by RemoveRect. Descends tree recursively, -// merges branches on the way back up. -// Returns 1 if record not found, 0 if success. -func RemoveRectRec(rect *Rect, id interface{}, node *Node, listNode **ListNode) bool { - ASSERT(rect != nil && node != nil && listNode != nil) - ASSERT(node.level >= 0) - - if node.IsInternalNode() { // not a leaf node - for index := 0; index < node.count; index++ { - if Overlap(rect, &(node.branch[index].rect)) { - if !RemoveRectRec(rect, id, node.branch[index].child, listNode) { - if node.branch[index].child.count >= MINNODES { - // child removed, just resize parent rect - node.branch[index].rect = NodeCover(node.branch[index].child) - } else { - // child removed, not enough entries in node, eliminate node - ReInsert(node.branch[index].child, listNode) - DisconnectBranch(node, index) // Must return after this call as count has changed - } - return false - } - } - } - return true - } else { // A leaf node - for index := 0; index < node.count; index++ { - if node.branch[index].data == id { - DisconnectBranch(node, index) // Must return after this call as count has changed - return false - } - } - return true - } -} - -// Decide whether two rectangles overlap. -func Overlap(rectA, rectB *Rect) bool { - ASSERT(rectA != nil && rectB != nil) - - for index := 0; index < NUMDIMS; index++ { - if rectA.min[index] > rectB.max[index] || - rectB.min[index] > rectA.max[index] { - return false - } - } - return true -} - -// Add a node to the reinsertion list. All its branches will later -// be reinserted into the index structure. -func ReInsert(node *Node, listNode **ListNode) { - newListNode := &ListNode{} - newListNode.node = node - newListNode.next = *listNode - *listNode = newListNode -} - -// Search in an index tree or subtree for all data retangles that overlap the argument rectangle. -func Search(node *Node, rect *Rect, foundCount *int, resultCallback ResultCallback, context interface{}) bool { - ASSERT(node != nil) - ASSERT(node.level >= 0) - ASSERT(rect != nil) - - if node.IsInternalNode() { - // This is an internal node in the tree - for index := 0; index < node.count; index++ { - if Overlap(rect, &node.branch[index].rect) { - if !Search(node.branch[index].child, rect, foundCount, resultCallback, context) { - // The callback indicated to stop searching - return false - } - } - } - } else { - // This is a leaf node - for index := 0; index < node.count; index++ { - if Overlap(rect, &node.branch[index].rect) { - id := node.branch[index].data - - // NOTE: There are different ways to return results. Here's where to modify - - *foundCount++ - if !resultCallback(id, context) { - return false // Don't continue searching - } - - } - } - } - - return true // Continue searching -} diff --git a/vendor/d4/rtree.go b/vendor/d4/rtree.go index 7634362..dfc541a 100644 --- a/vendor/d4/rtree.go +++ b/vendor/d4/rtree.go @@ -56,7 +56,7 @@ const ( USE_SPHERICAL_VOLUME = true // Better split classification, may be slower on some systems ) -type ResultCallback func(dataID interface{}, context interface{}) bool +type ResultCallback func(dataID, context interface{}) bool var unitSphereVolume float64 diff --git a/vendor/d4d/rtree.go b/vendor/d4d/rtree.go deleted file mode 100644 index 1a64f4b..0000000 --- a/vendor/d4d/rtree.go +++ /dev/null @@ -1,815 +0,0 @@ -//generated; DO NOT EDIT! - -/* - -TITLE - - R-TREES: A DYNAMIC INDEX STRUCTURE FOR SPATIAL SEARCHING - -DESCRIPTION - - A Go version of the RTree algorithm. - For more information please read the comments in rtree.go - -AUTHORS - - * 1983 Original algorithm and test code by Antonin Guttman and Michael Stonebraker, UC Berkely - * 1994 ANCI C ported from original test code by Melinda Green - melinda@superliminal.com - * 1995 Sphere volume fix for degeneracy problem submitted by Paul Brook - * 2004 Templated C++ port by Greg Douglas - * 2016 Go port by Josh Baker - -LICENSE: - - Entirely free for all uses. Enjoy! - -*/ - -// Implementation of RTree, a multidimensional bounding rectangle tree. -package rtree - -import "math" - -func Min(a, b float64) float64 { - if a < b { - return a - } - return b -} -func Max(a, b float64) float64 { - if a > b { - return a - } - return b -} -func ASSERT(condition bool) { - if _DEBUG && !condition { - panic("assertion failed") - } -} - -const ( - _DEBUG = true - NUMDIMS = 4 - MAXNODES = 8 - MINNODES = MAXNODES / 2 - USE_SPHERICAL_VOLUME = true // Better split classification, may be slower on some systems -) - -type ResultCallback func(dataID interface{}, context interface{}) bool - -var unitSphereVolume float64 - -func init() { - // Precomputed volumes of the unit spheres for the first few dimensions - unitSphereVolume = []float64{ - 0.000000, 2.000000, 3.141593, // Dimension 0,1,2 - 4.188790, 4.934802, 5.263789, // Dimension 3,4,5 - 5.167713, 4.724766, 4.058712, // Dimension 6,7,8 - 3.298509, 2.550164, 1.884104, // Dimension 9,10,11 - 1.335263, 0.910629, 0.599265, // Dimension 12,13,14 - 0.381443, 0.235331, 0.140981, // Dimension 15,16,17 - 0.082146, 0.046622, 0.025807, // Dimension 18,19,20 - }[NUMDIMS] -} - -type RTree struct { - root *Node ///< Root of tree - unitSphereVolume float64 ///< Unit sphere constant for required number of dimensions -} - -/// Minimal bounding rectangle (n-dimensional) -type Rect struct { - min [NUMDIMS]float64 ///< Min dimensions of bounding box - max [NUMDIMS]float64 ///< Max dimensions of bounding box -} - -/// May be data or may be another subtree -/// The parents level determines this. -/// If the parents level is 0, then this is data -type Branch struct { - rect Rect ///< Bounds - child *Node ///< Child node - data interface{} ///< Data Id or Ptr -} - -/// Node for each branch level -type Node struct { - count int ///< Count - level int ///< Leaf is zero, others positive - branch [MAXNODES]Branch ///< Branch -} - -func (node *Node) IsInternalNode() bool { - return (node.level > 0) // Not a leaf, but a internal node -} -func (node *Node) IsLeaf() bool { - return (node.level == 0) // A leaf, contains data -} - -/// A link list of nodes for reinsertion after a delete operation -type ListNode struct { - next *ListNode ///< Next in list - node *Node ///< Node -} - -const NOT_TAKEN = -1 // indicates that position - -/// Variables for finding a split partition -type PartitionVars struct { - partition [MAXNODES + 1]int - total int - minFill int - count [2]int - cover [2]Rect - area [2]float64 - - branchBuf [MAXNODES + 1]Branch - branchCount int - coverSplit Rect - coverSplitArea float64 -} - -func NewRTree() *RTree { - ASSERT(MAXNODES > MINNODES) - ASSERT(MINNODES > 0) - - // We only support machine word size simple data type eg. integer index or object pointer. - // Since we are storing as union with non data branch - //ASSERT(sizeof(DATATYPE) == sizeof(void*) || sizeof(DATATYPE) == sizeof(int)); - - return &RTree{ - root: &Node{}, - } -} - -/// Insert entry -/// \param a_min Min of bounding rect -/// \param a_max Max of bounding rect -/// \param a_dataId Positive Id of data. Maybe zero, but negative numbers not allowed. -func (tr *RTree) Insert(min, max [NUMDIMS]float64, dataId interface{}) { - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(min[index] <= max[index]) - } - } //_DEBUG - var branch Branch - branch.data = dataId - branch.child = nil - for axis := 0; axis < NUMDIMS; axis++ { - branch.rect.min[axis] = min[axis] - branch.rect.max[axis] = max[axis] - } - InsertRect(&branch, &tr.root, 0) -} - -/// Remove entry -/// \param a_min Min of bounding rect -/// \param a_max Max of bounding rect -/// \param a_dataId Positive Id of data. Maybe zero, but negative numbers not allowed. -func (tr *RTree) Remove(min, max [NUMDIMS]float64, dataId interface{}) { - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(min[index] <= max[index]) - } - } //_DEBUG - var rect Rect - for axis := 0; axis < NUMDIMS; axis++ { - rect.min[axis] = min[axis] - rect.max[axis] = max[axis] - } - RemoveRect(&rect, dataId, &tr.root) -} - -/// Find all within search rectangle -/// \param a_min Min of search bounding rect -/// \param a_max Max of search bounding rect -/// \param a_searchResult Search result array. Caller should set grow size. Function will reset, not append to array. -/// \param a_resultCallback Callback function to return result. Callback should return 'true' to continue searching -/// \param a_context User context to pass as parameter to a_resultCallback -/// \return Returns the number of entries found -func (tr *RTree) Search(min, max [NUMDIMS]float64, resultCallback ResultCallback, context interface{}) int { - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(min[index] <= max[index]) - } - } //_DEBUG - var rect Rect - for axis := 0; axis < NUMDIMS; axis++ { - rect.min[axis] = min[axis] - rect.max[axis] = max[axis] - } - // NOTE: May want to return search result another way, perhaps returning the number of found elements here. - - foundCount := 0 - Search(tr.root, &rect, &foundCount, resultCallback, context) - return foundCount -} - -/// Count the data elements in this container. This is slow as no internal counter is maintained. -func (tr *RTree) Count() int { - var count int - CountRec(tr.root, &count) - return count -} - -func CountRec(node *Node, count *int) { - if node.IsInternalNode() { // not a leaf node - for index := 0; index < node.count; index++ { - CountRec(node.branch[index].child, count) - } - } else { // A leaf node - *count += node.count - } -} - -/// Remove all entries from tree -func (tr *RTree) RemoveAll() { - // Delete all existing nodes - tr.root = &Node{} -} - -func InitNode(node *Node) { - node.count = 0 - node.level = -1 -} - -func InitRect(rect *Rect) { - for index := 0; index < NUMDIMS; index++ { - rect.min[index] = 0 - rect.max[index] = 0 - } -} - -// Inserts a new data rectangle into the index structure. -// Recursively descends tree, propagates splits back up. -// Returns 0 if node was not split. Old node updated. -// If node was split, returns 1 and sets the pointer pointed to by -// new_node to point to the new node. Old node updated to become one of two. -// The level argument specifies the number of steps up from the leaf -// level to insert; e.g. a data rectangle goes in at level = 0. -func InsertRectRec(branch *Branch, node *Node, newNode **Node, level int) bool { - ASSERT(node != nil && newNode != nil) - ASSERT(level >= 0 && level <= node.level) - - // recurse until we reach the correct level for the new record. data records - // will always be called with a_level == 0 (leaf) - if node.level > level { - // Still above level for insertion, go down tree recursively - var otherNode *Node - //var newBranch Branch - - // find the optimal branch for this record - index := PickBranch(&branch.rect, node) - - // recursively insert this record into the picked branch - childWasSplit := InsertRectRec(branch, node.branch[index].child, &otherNode, level) - - if !childWasSplit { - // Child was not split. Merge the bounding box of the new record with the - // existing bounding box - node.branch[index].rect = CombineRect(&branch.rect, &(node.branch[index].rect)) - return false - } else { - // Child was split. The old branches are now re-partitioned to two nodes - // so we have to re-calculate the bounding boxes of each node - node.branch[index].rect = NodeCover(node.branch[index].child) - var newBranch Branch - newBranch.child = otherNode - newBranch.rect = NodeCover(otherNode) - - // The old node is already a child of a_node. Now add the newly-created - // node to a_node as well. a_node might be split because of that. - return AddBranch(&newBranch, node, newNode) - } - } else if node.level == level { - // We have reached level for insertion. Add rect, split if necessary - return AddBranch(branch, node, newNode) - } else { - // Should never occur - ASSERT(false) - return false - } -} - -// Insert a data rectangle into an index structure. -// InsertRect provides for splitting the root; -// returns 1 if root was split, 0 if it was not. -// The level argument specifies the number of steps up from the leaf -// level to insert; e.g. a data rectangle goes in at level = 0. -// InsertRect2 does the recursion. -// -func InsertRect(branch *Branch, root **Node, level int) bool { - ASSERT(root != nil) - ASSERT(level >= 0 && level <= (*root).level) - if _DEBUG { - for index := 0; index < NUMDIMS; index++ { - ASSERT(branch.rect.min[index] <= branch.rect.max[index]) - } - } //_DEBUG - - var newNode *Node - - if InsertRectRec(branch, *root, &newNode, level) { // Root split - - // Grow tree taller and new root - newRoot := &Node{} - newRoot.level = (*root).level + 1 - - var newBranch Branch - - // add old root node as a child of the new root - newBranch.rect = NodeCover(*root) - newBranch.child = *root - AddBranch(&newBranch, newRoot, nil) - - // add the split node as a child of the new root - newBranch.rect = NodeCover(newNode) - newBranch.child = newNode - AddBranch(&newBranch, newRoot, nil) - - // set the new root as the root node - *root = newRoot - - return true - } - - return false -} - -// Find the smallest rectangle that includes all rectangles in branches of a node. -func NodeCover(node *Node) Rect { - ASSERT(node != nil) - - rect := node.branch[0].rect - for index := 1; index < node.count; index++ { - rect = CombineRect(&rect, &(node.branch[index].rect)) - } - - return rect -} - -// Add a branch to a node. Split the node if necessary. -// Returns 0 if node not split. Old node updated. -// Returns 1 if node split, sets *new_node to address of new node. -// Old node updated, becomes one of two. -func AddBranch(branch *Branch, node *Node, newNode **Node) bool { - ASSERT(branch != nil) - ASSERT(node != nil) - - if node.count < MAXNODES { // Split won't be necessary - - node.branch[node.count] = *branch - node.count++ - - return false - } else { - ASSERT(newNode != nil) - - SplitNode(node, branch, newNode) - return true - } -} - -// Disconnect a dependent node. -// Caller must return (or stop using iteration index) after this as count has changed -func DisconnectBranch(node *Node, index int) { - ASSERT(node != nil && (index >= 0) && (index < MAXNODES)) - ASSERT(node.count > 0) - - // Remove element by swapping with the last element to prevent gaps in array - node.branch[index] = node.branch[node.count-1] - - node.count-- -} - -// Pick a branch. Pick the one that will need the smallest increase -// in area to accomodate the new rectangle. This will result in the -// least total area for the covering rectangles in the current node. -// In case of a tie, pick the one which was smaller before, to get -// the best resolution when searching. -func PickBranch(rect *Rect, node *Node) int { - ASSERT(rect != nil && node != nil) - - var firstTime bool = true - var increase float64 - var bestIncr float64 = -1 - var area float64 - var bestArea float64 - var best int - var tempRect Rect - - for index := 0; index < node.count; index++ { - curRect := &node.branch[index].rect - area = CalcRectVolume(curRect) - tempRect = CombineRect(rect, curRect) - increase = CalcRectVolume(&tempRect) - area - if (increase < bestIncr) || firstTime { - best = index - bestArea = area - bestIncr = increase - firstTime = false - } else if (increase == bestIncr) && (area < bestArea) { - best = index - bestArea = area - bestIncr = increase - } - } - return best -} - -// Combine two rectangles into larger one containing both -func CombineRect(rectA, rectB *Rect) Rect { - ASSERT(rectA != nil && rectB != nil) - - var newRect Rect - - for index := 0; index < NUMDIMS; index++ { - newRect.min[index] = Min(rectA.min[index], rectB.min[index]) - newRect.max[index] = Max(rectA.max[index], rectB.max[index]) - } - - return newRect -} - -// Split a node. -// Divides the nodes branches and the extra one between two nodes. -// Old node is one of the new ones, and one really new one is created. -// Tries more than one method for choosing a partition, uses best result. -func SplitNode(node *Node, branch *Branch, newNode **Node) { - ASSERT(node != nil) - ASSERT(branch != nil) - - // Could just use local here, but member or external is faster since it is reused - var localVars PartitionVars - parVars := &localVars - - // Load all the branches into a buffer, initialize old node - GetBranches(node, branch, parVars) - - // Find partition - ChoosePartition(parVars, MINNODES) - - // Create a new node to hold (about) half of the branches - *newNode = &Node{} - (*newNode).level = node.level - - // Put branches from buffer into 2 nodes according to the chosen partition - node.count = 0 - LoadNodes(node, *newNode, parVars) - - ASSERT((node.count + (*newNode).count) == parVars.total) -} - -// Calculate the n-dimensional volume of a rectangle -func RectVolume(rect *Rect) float64 { - ASSERT(rect != nil) - - var volume float64 = 1 - - for index := 0; index < NUMDIMS; index++ { - volume *= rect.max[index] - rect.min[index] - } - - ASSERT(volume >= 0) - - return volume -} - -// The exact volume of the bounding sphere for the given Rect -func RectSphericalVolume(rect *Rect) float64 { - ASSERT(rect != nil) - - var sumOfSquares float64 = 0 - var radius float64 - - for index := 0; index < NUMDIMS; index++ { - halfExtent := (rect.max[index] - rect.min[index]) * 0.5 - sumOfSquares += halfExtent * halfExtent - } - - radius = math.Sqrt(sumOfSquares) - - // Pow maybe slow, so test for common dims like 2,3 and just use x*x, x*x*x. - if NUMDIMS == 4 { - return (radius * radius * radius * radius * unitSphereVolume) - } else if NUMDIMS == 3 { - return (radius * radius * radius * unitSphereVolume) - } else if NUMDIMS == 2 { - return (radius * radius * unitSphereVolume) - } else { - return (math.Pow(radius, NUMDIMS) * unitSphereVolume) - } -} - -// Use one of the methods to calculate retangle volume -func CalcRectVolume(rect *Rect) float64 { - if USE_SPHERICAL_VOLUME { - return RectSphericalVolume(rect) // Slower but helps certain merge cases - } else { // RTREE_USE_SPHERICAL_VOLUME - return RectVolume(rect) // Faster but can cause poor merges - } // RTREE_USE_SPHERICAL_VOLUME -} - -// Load branch buffer with branches from full node plus the extra branch. -func GetBranches(node *Node, branch *Branch, parVars *PartitionVars) { - ASSERT(node != nil) - ASSERT(branch != nil) - - ASSERT(node.count == MAXNODES) - - // Load the branch buffer - for index := 0; index < MAXNODES; index++ { - parVars.branchBuf[index] = node.branch[index] - } - parVars.branchBuf[MAXNODES] = *branch - parVars.branchCount = MAXNODES + 1 - - // Calculate rect containing all in the set - parVars.coverSplit = parVars.branchBuf[0].rect - for index := 1; index < MAXNODES+1; index++ { - parVars.coverSplit = CombineRect(&parVars.coverSplit, &parVars.branchBuf[index].rect) - } - parVars.coverSplitArea = CalcRectVolume(&parVars.coverSplit) -} - -// Method #0 for choosing a partition: -// As the seeds for the two groups, pick the two rects that would waste the -// most area if covered by a single rectangle, i.e. evidently the worst pair -// to have in the same group. -// Of the remaining, one at a time is chosen to be put in one of the two groups. -// The one chosen is the one with the greatest difference in area expansion -// depending on which group - the rect most strongly attracted to one group -// and repelled from the other. -// If one group gets too full (more would force other group to violate min -// fill requirement) then other group gets the rest. -// These last are the ones that can go in either group most easily. -func ChoosePartition(parVars *PartitionVars, minFill int) { - ASSERT(parVars != nil) - - var biggestDiff float64 - var group, chosen, betterGroup int - - InitParVars(parVars, parVars.branchCount, minFill) - PickSeeds(parVars) - - for ((parVars.count[0] + parVars.count[1]) < parVars.total) && - (parVars.count[0] < (parVars.total - parVars.minFill)) && - (parVars.count[1] < (parVars.total - parVars.minFill)) { - biggestDiff = -1 - for index := 0; index < parVars.total; index++ { - if NOT_TAKEN == parVars.partition[index] { - curRect := &parVars.branchBuf[index].rect - rect0 := CombineRect(curRect, &parVars.cover[0]) - rect1 := CombineRect(curRect, &parVars.cover[1]) - growth0 := CalcRectVolume(&rect0) - parVars.area[0] - growth1 := CalcRectVolume(&rect1) - parVars.area[1] - diff := growth1 - growth0 - if diff >= 0 { - group = 0 - } else { - group = 1 - diff = -diff - } - - if diff > biggestDiff { - biggestDiff = diff - chosen = index - betterGroup = group - } else if (diff == biggestDiff) && (parVars.count[group] < parVars.count[betterGroup]) { - chosen = index - betterGroup = group - } - } - } - Classify(chosen, betterGroup, parVars) - } - - // If one group too full, put remaining rects in the other - if (parVars.count[0] + parVars.count[1]) < parVars.total { - if parVars.count[0] >= parVars.total-parVars.minFill { - group = 1 - } else { - group = 0 - } - for index := 0; index < parVars.total; index++ { - if NOT_TAKEN == parVars.partition[index] { - Classify(index, group, parVars) - } - } - } - - ASSERT((parVars.count[0] + parVars.count[1]) == parVars.total) - ASSERT((parVars.count[0] >= parVars.minFill) && - (parVars.count[1] >= parVars.minFill)) -} - -// Copy branches from the buffer into two nodes according to the partition. -func LoadNodes(nodeA, nodeB *Node, parVars *PartitionVars) { - ASSERT(nodeA != nil) - ASSERT(nodeB != nil) - ASSERT(parVars != nil) - - for index := 0; index < parVars.total; index++ { - ASSERT(parVars.partition[index] == 0 || parVars.partition[index] == 1) - - targetNodeIndex := parVars.partition[index] - targetNodes := []*Node{nodeA, nodeB} - - // It is assured that AddBranch here will not cause a node split. - nodeWasSplit := AddBranch(&parVars.branchBuf[index], targetNodes[targetNodeIndex], nil) - ASSERT(!nodeWasSplit) - } -} - -// Initialize a PartitionVars structure. -func InitParVars(parVars *PartitionVars, maxRects, minFill int) { - ASSERT(parVars != nil) - - parVars.count[0] = 0 - parVars.count[1] = 0 - parVars.area[0] = 0 - parVars.area[1] = 0 - parVars.total = maxRects - parVars.minFill = minFill - for index := 0; index < maxRects; index++ { - parVars.partition[index] = NOT_TAKEN - } -} - -func PickSeeds(parVars *PartitionVars) { - var seed0, seed1 int - var worst, waste float64 - var area [MAXNODES + 1]float64 - - for index := 0; index < parVars.total; index++ { - area[index] = CalcRectVolume(&parVars.branchBuf[index].rect) - } - - worst = -parVars.coverSplitArea - 1 - for indexA := 0; indexA < parVars.total-1; indexA++ { - for indexB := indexA + 1; indexB < parVars.total; indexB++ { - oneRect := CombineRect(&parVars.branchBuf[indexA].rect, &parVars.branchBuf[indexB].rect) - waste = CalcRectVolume(&oneRect) - area[indexA] - area[indexB] - if waste > worst { - worst = waste - seed0 = indexA - seed1 = indexB - } - } - } - - Classify(seed0, 0, parVars) - Classify(seed1, 1, parVars) -} - -// Put a branch in one of the groups. -func Classify(index, group int, parVars *PartitionVars) { - ASSERT(parVars != nil) - ASSERT(NOT_TAKEN == parVars.partition[index]) - - parVars.partition[index] = group - - // Calculate combined rect - if parVars.count[group] == 0 { - parVars.cover[group] = parVars.branchBuf[index].rect - } else { - parVars.cover[group] = CombineRect(&parVars.branchBuf[index].rect, &parVars.cover[group]) - } - - // Calculate volume of combined rect - parVars.area[group] = CalcRectVolume(&parVars.cover[group]) - - parVars.count[group]++ -} - -// Delete a data rectangle from an index structure. -// Pass in a pointer to a Rect, the tid of the record, ptr to ptr to root node. -// Returns 1 if record not found, 0 if success. -// RemoveRect provides for eliminating the root. -func RemoveRect(rect *Rect, id interface{}, root **Node) bool { - ASSERT(rect != nil && root != nil) - ASSERT(*root != nil) - - var reInsertList *ListNode - - if !RemoveRectRec(rect, id, *root, &reInsertList) { - // Found and deleted a data item - // Reinsert any branches from eliminated nodes - for reInsertList != nil { - tempNode := reInsertList.node - - for index := 0; index < tempNode.count; index++ { - // TODO go over this code. should I use (tempNode->m_level - 1)? - InsertRect(&tempNode.branch[index], root, tempNode.level) - } - reInsertList = reInsertList.next - } - - // Check for redundant root (not leaf, 1 child) and eliminate TODO replace - // if with while? In case there is a whole branch of redundant roots... - if (*root).count == 1 && (*root).IsInternalNode() { - tempNode := (*root).branch[0].child - - ASSERT(tempNode != nil) - *root = tempNode - } - return false - } else { - return true - } -} - -// Delete a rectangle from non-root part of an index structure. -// Called by RemoveRect. Descends tree recursively, -// merges branches on the way back up. -// Returns 1 if record not found, 0 if success. -func RemoveRectRec(rect *Rect, id interface{}, node *Node, listNode **ListNode) bool { - ASSERT(rect != nil && node != nil && listNode != nil) - ASSERT(node.level >= 0) - - if node.IsInternalNode() { // not a leaf node - for index := 0; index < node.count; index++ { - if Overlap(rect, &(node.branch[index].rect)) { - if !RemoveRectRec(rect, id, node.branch[index].child, listNode) { - if node.branch[index].child.count >= MINNODES { - // child removed, just resize parent rect - node.branch[index].rect = NodeCover(node.branch[index].child) - } else { - // child removed, not enough entries in node, eliminate node - ReInsert(node.branch[index].child, listNode) - DisconnectBranch(node, index) // Must return after this call as count has changed - } - return false - } - } - } - return true - } else { // A leaf node - for index := 0; index < node.count; index++ { - if node.branch[index].data == id { - DisconnectBranch(node, index) // Must return after this call as count has changed - return false - } - } - return true - } -} - -// Decide whether two rectangles overlap. -func Overlap(rectA, rectB *Rect) bool { - ASSERT(rectA != nil && rectB != nil) - - for index := 0; index < NUMDIMS; index++ { - if rectA.min[index] > rectB.max[index] || - rectB.min[index] > rectA.max[index] { - return false - } - } - return true -} - -// Add a node to the reinsertion list. All its branches will later -// be reinserted into the index structure. -func ReInsert(node *Node, listNode **ListNode) { - newListNode := &ListNode{} - newListNode.node = node - newListNode.next = *listNode - *listNode = newListNode -} - -// Search in an index tree or subtree for all data retangles that overlap the argument rectangle. -func Search(node *Node, rect *Rect, foundCount *int, resultCallback ResultCallback, context interface{}) bool { - ASSERT(node != nil) - ASSERT(node.level >= 0) - ASSERT(rect != nil) - - if node.IsInternalNode() { - // This is an internal node in the tree - for index := 0; index < node.count; index++ { - if Overlap(rect, &node.branch[index].rect) { - if !Search(node.branch[index].child, rect, foundCount, resultCallback, context) { - // The callback indicated to stop searching - return false - } - } - } - } else { - // This is a leaf node - for index := 0; index < node.count; index++ { - if Overlap(rect, &node.branch[index].rect) { - id := node.branch[index].data - - // NOTE: There are different ways to return results. Here's where to modify - - *foundCount++ - if !resultCallback(id, context) { - return false // Don't continue searching - } - - } - } - } - - return true // Continue searching -}