| /* |
| * Copyright 2012 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "src/core/SkRTree.h" |
| |
| SkRTree::SkRTree() : fCount(0) {} |
| |
| SkRect SkRTree::getRootBound() const { |
| if (fCount) { |
| return fRoot.fBounds; |
| } else { |
| return SkRect::MakeEmpty(); |
| } |
| } |
| |
| void SkRTree::insert(const SkRect boundsArray[], int N) { |
| SkASSERT(0 == fCount); |
| |
| SkTDArray<Branch> branches; |
| branches.setReserve(N); |
| |
| for (int i = 0; i < N; i++) { |
| const SkRect& bounds = boundsArray[i]; |
| if (bounds.isEmpty()) { |
| continue; |
| } |
| |
| Branch* b = branches.push(); |
| b->fBounds = bounds; |
| b->fOpIndex = i; |
| } |
| |
| fCount = branches.count(); |
| if (fCount) { |
| if (1 == fCount) { |
| fNodes.setReserve(1); |
| Node* n = this->allocateNodeAtLevel(0); |
| n->fNumChildren = 1; |
| n->fChildren[0] = branches[0]; |
| fRoot.fSubtree = n; |
| fRoot.fBounds = branches[0].fBounds; |
| } else { |
| fNodes.setReserve(CountNodes(fCount)); |
| fRoot = this->bulkLoad(&branches); |
| } |
| } |
| } |
| |
| SkRTree::Node* SkRTree::allocateNodeAtLevel(uint16_t level) { |
| SkDEBUGCODE(Node* p = fNodes.begin()); |
| Node* out = fNodes.push(); |
| SkASSERT(fNodes.begin() == p); // If this fails, we didn't setReserve() enough. |
| out->fNumChildren = 0; |
| out->fLevel = level; |
| return out; |
| } |
| |
| // This function parallels bulkLoad, but just counts how many nodes bulkLoad would allocate. |
| int SkRTree::CountNodes(int branches) { |
| if (branches == 1) { |
| return 1; |
| } |
| int numBranches = branches / kMaxChildren; |
| int remainder = branches % kMaxChildren; |
| if (remainder > 0) { |
| numBranches++; |
| if (remainder >= kMinChildren) { |
| remainder = 0; |
| } else { |
| remainder = kMinChildren - remainder; |
| } |
| } |
| int currentBranch = 0; |
| int nodes = 0; |
| while (currentBranch < branches) { |
| int incrementBy = kMaxChildren; |
| if (remainder != 0) { |
| if (remainder <= kMaxChildren - kMinChildren) { |
| incrementBy -= remainder; |
| remainder = 0; |
| } else { |
| incrementBy = kMinChildren; |
| remainder -= kMaxChildren - kMinChildren; |
| } |
| } |
| nodes++; |
| currentBranch++; |
| for (int k = 1; k < incrementBy && currentBranch < branches; ++k) { |
| currentBranch++; |
| } |
| } |
| return nodes + CountNodes(nodes); |
| } |
| |
| SkRTree::Branch SkRTree::bulkLoad(SkTDArray<Branch>* branches, int level) { |
| if (branches->count() == 1) { // Only one branch. It will be the root. |
| return (*branches)[0]; |
| } |
| |
| // We might sort our branches here, but we expect Blink gives us a reasonable x,y order. |
| // Skipping a call to sort (in Y) here resulted in a 17% win for recording with negligible |
| // difference in playback speed. |
| int numBranches = branches->count() / kMaxChildren; |
| int remainder = branches->count() % kMaxChildren; |
| int newBranches = 0; |
| |
| if (remainder > 0) { |
| ++numBranches; |
| // If the remainder isn't enough to fill a node, we'll add fewer nodes to other branches. |
| if (remainder >= kMinChildren) { |
| remainder = 0; |
| } else { |
| remainder = kMinChildren - remainder; |
| } |
| } |
| |
| int currentBranch = 0; |
| while (currentBranch < branches->count()) { |
| int incrementBy = kMaxChildren; |
| if (remainder != 0) { |
| // if need be, omit some nodes to make up for remainder |
| if (remainder <= kMaxChildren - kMinChildren) { |
| incrementBy -= remainder; |
| remainder = 0; |
| } else { |
| incrementBy = kMinChildren; |
| remainder -= kMaxChildren - kMinChildren; |
| } |
| } |
| Node* n = allocateNodeAtLevel(level); |
| n->fNumChildren = 1; |
| n->fChildren[0] = (*branches)[currentBranch]; |
| Branch b; |
| b.fBounds = (*branches)[currentBranch].fBounds; |
| b.fSubtree = n; |
| ++currentBranch; |
| for (int k = 1; k < incrementBy && currentBranch < branches->count(); ++k) { |
| b.fBounds.join((*branches)[currentBranch].fBounds); |
| n->fChildren[k] = (*branches)[currentBranch]; |
| ++n->fNumChildren; |
| ++currentBranch; |
| } |
| (*branches)[newBranches] = b; |
| ++newBranches; |
| } |
| branches->setCount(newBranches); |
| return this->bulkLoad(branches, level + 1); |
| } |
| |
| void SkRTree::search(const SkRect& query, SkTDArray<int>* results) const { |
| if (fCount > 0 && SkRect::Intersects(fRoot.fBounds, query)) { |
| this->search(fRoot.fSubtree, query, results); |
| } |
| } |
| |
| void SkRTree::search(Node* node, const SkRect& query, SkTDArray<int>* results) const { |
| for (int i = 0; i < node->fNumChildren; ++i) { |
| if (SkRect::Intersects(node->fChildren[i].fBounds, query)) { |
| if (0 == node->fLevel) { |
| results->push_back(node->fChildren[i].fOpIndex); |
| } else { |
| this->search(node->fChildren[i].fSubtree, query, results); |
| } |
| } |
| } |
| } |
| |
| size_t SkRTree::bytesUsed() const { |
| size_t byteCount = sizeof(SkRTree); |
| |
| byteCount += fNodes.reserved() * sizeof(Node); |
| |
| return byteCount; |
| } |