ecency-mobile/ios/Pods/boost-for-react-native/boost/polygon/detail/max_cover.hpp

279 lines
12 KiB
C++

/*
Copyright 2008 Intel Corporation
Use, modification and distribution are subject to the Boost Software License,
Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
http://www.boost.org/LICENSE_1_0.txt).
*/
#ifndef BOOST_POLYGON_MAX_COVER_HPP
#define BOOST_POLYGON_MAX_COVER_HPP
namespace boost { namespace polygon{
template <typename Unit>
struct MaxCover {
typedef interval_data<Unit> Interval;
typedef rectangle_data<Unit> Rectangle;
class Node {
private:
std::vector<Node*> children_;
std::set<Interval> tracedPaths_;
public:
Rectangle rect;
Node() : children_(), tracedPaths_(), rect() {}
Node(const Rectangle rectIn) : children_(), tracedPaths_(), rect(rectIn) {}
typedef typename std::vector<Node*>::iterator iterator;
inline iterator begin() { return children_.begin(); }
inline iterator end() { return children_.end(); }
inline void add(Node* child) { children_.push_back(child); }
inline bool tracedPath(const Interval& ivl) const {
return tracedPaths_.find(ivl) != tracedPaths_.end();
}
inline void addPath(const Interval& ivl) {
tracedPaths_.insert(tracedPaths_.end(), ivl);
}
};
typedef std::pair<std::pair<Unit, Interval>, Node* > EdgeAssociation;
class lessEdgeAssociation : public std::binary_function<const EdgeAssociation&, const EdgeAssociation&, bool> {
public:
inline lessEdgeAssociation() {}
inline bool operator () (const EdgeAssociation& elem1, const EdgeAssociation& elem2) const {
if(elem1.first.first < elem2.first.first) return true;
if(elem1.first.first > elem2.first.first) return false;
return elem1.first.second < elem2.first.second;
}
};
template <class cT>
static inline void getMaxCover(cT& outputContainer, Node* node, orientation_2d orient) {
Interval rectIvl = node->rect.get(orient);
if(node->tracedPath(rectIvl)) {
return;
}
node->addPath(rectIvl);
if(node->begin() == node->end()) {
//std::cout << "WRITE OUT 3: " << node->rect << std::endl;
outputContainer.push_back(copy_construct<typename cT::value_type, Rectangle>(node->rect));
return;
}
bool writeOut = true;
for(typename Node::iterator itr = node->begin(); itr != node->end(); ++itr) {
getMaxCover(outputContainer, *itr, orient, node->rect); //get rectangles down path
Interval nodeIvl = (*itr)->rect.get(orient);
if(contains(nodeIvl, rectIvl, true)) writeOut = false;
}
if(writeOut) {
//std::cout << "WRITE OUT 2: " << node->rect << std::endl;
outputContainer.push_back(copy_construct<typename cT::value_type, Rectangle>(node->rect));
}
}
struct stack_element {
inline stack_element() :
node(), rect(), itr() {}
inline stack_element(Node* n,
const Rectangle& r,
typename Node::iterator i) :
node(n), rect(r), itr(i) {}
Node* node;
Rectangle rect;
typename Node::iterator itr;
};
template <class cT>
static inline void getMaxCover(cT& outputContainer, Node* node, orientation_2d orient,
Rectangle rect) {
//std::cout << "New Root\n";
std::vector<stack_element> stack;
typename Node::iterator itr = node->begin();
do {
//std::cout << "LOOP\n";
//std::cout << node->rect << std::endl;
Interval rectIvl = rect.get(orient);
Interval nodeIvl = node->rect.get(orient);
bool iresult = intersect(rectIvl, nodeIvl, false);
bool tresult = !node->tracedPath(rectIvl);
//std::cout << (itr != node->end()) << " " << iresult << " " << tresult << std::endl;
Rectangle nextRect1 = Rectangle(rectIvl, rectIvl);
Unit low = rect.get(orient.get_perpendicular()).low();
Unit high = node->rect.get(orient.get_perpendicular()).high();
nextRect1.set(orient.get_perpendicular(), Interval(low, high));
if(iresult && tresult) {
node->addPath(rectIvl);
bool writeOut = true;
//check further visibility beyond this node
for(typename Node::iterator itr2 = node->begin(); itr2 != node->end(); ++itr2) {
Interval nodeIvl3 = (*itr2)->rect.get(orient);
//if a child of this node can contain the interval then we can extend through
if(contains(nodeIvl3, rectIvl, true)) writeOut = false;
//std::cout << "child " << (*itr2)->rect << std::endl;
}
Rectangle nextRect2 = Rectangle(rectIvl, rectIvl);
Unit low2 = rect.get(orient.get_perpendicular()).low();
Unit high2 = node->rect.get(orient.get_perpendicular()).high();
nextRect2.set(orient.get_perpendicular(), Interval(low2, high2));
if(writeOut) {
//std::cout << "write out " << nextRect << std::endl;
outputContainer.push_back(copy_construct<typename cT::value_type, Rectangle>(nextRect2));
} else {
//std::cout << "suppress " << nextRect << std::endl;
}
}
if(itr != node->end() && iresult && tresult) {
//std::cout << "recurse into child\n";
stack.push_back(stack_element(node, rect, itr));
rect = nextRect1;
node = *itr;
itr = node->begin();
} else {
if(!stack.empty()) {
//std::cout << "recurse out of child\n";
node = stack.back().node;
rect = stack.back().rect;
itr = stack.back().itr;
stack.pop_back();
} else {
//std::cout << "empty stack\n";
//if there were no children of the root node
// Rectangle nextRect = Rectangle(rectIvl, rectIvl);
// Unit low = rect.get(orient.get_perpendicular()).low();
// Unit high = node->rect.get(orient.get_perpendicular()).high();
// nextRect.set(orient.get_perpendicular(), Interval(low, high));
// outputContainer.push_back(copy_construct<typename cT::value_type, Rectangle>(nextRect));
}
//std::cout << "increment " << (itr != node->end()) << std::endl;
if(itr != node->end()) {
++itr;
if(itr != node->end()) {
//std::cout << "recurse into next child.\n";
stack.push_back(stack_element(node, rect, itr));
Interval rectIvl2 = rect.get(orient);
Interval nodeIvl2 = node->rect.get(orient);
/*bool iresult =*/ intersect(rectIvl2, nodeIvl2, false);
Rectangle nextRect2 = Rectangle(rectIvl2, rectIvl2);
Unit low2 = rect.get(orient.get_perpendicular()).low();
Unit high2 = node->rect.get(orient.get_perpendicular()).high();
nextRect2.set(orient.get_perpendicular(), Interval(low2, high2));
rect = nextRect2;
//std::cout << "rect for next child" << rect << std::endl;
node = *itr;
itr = node->begin();
}
}
}
} while(!stack.empty() || itr != node->end());
}
/* Function recursive version of getMaxCover
Because the code is so much simpler than the loop algorithm I retain it for clarity
template <class cT>
static inline void getMaxCover(cT& outputContainer, Node* node, orientation_2d orient,
const Rectangle& rect) {
Interval rectIvl = rect.get(orient);
Interval nodeIvl = node->rect.get(orient);
if(!intersect(rectIvl, nodeIvl, false)) {
return;
}
if(node->tracedPath(rectIvl)) {
return;
}
node->addPath(rectIvl);
Rectangle nextRect(rectIvl, rectIvl);
Unit low = rect.get(orient.get_perpendicular()).low();
Unit high = node->rect.get(orient.get_perpendicular()).high();
nextRect.set(orient.get_perpendicular(), Interval(low, high));
bool writeOut = true;
rectIvl = nextRect.get(orient);
for(typename Node::iterator itr = node->begin(); itr != node->end(); ++itr) {
nodeIvl = (*itr)->rect.get(orient);
if(contains(nodeIvl, rectIvl, true)) writeOut = false;
}
if(writeOut) {
outputContainer.push_back(copy_construct<typename cT::value_type, Rectangle>(nextRect));
}
for(typename Node::iterator itr = node->begin(); itr != node->end(); ++itr) {
getMaxCover(outputContainer, *itr, orient, nextRect);
}
}
*/
//iterator range is assummed to be in topological order meaning all node's trailing
//edges are in sorted order
template <class iT>
static inline void computeDag(iT beginNode, iT endNode, orientation_2d orient,
std::size_t size) {
std::vector<EdgeAssociation> leadingEdges;
leadingEdges.reserve(size);
for(iT iter = beginNode; iter != endNode; ++iter) {
Node* nodep = &(*iter);
Unit leading = nodep->rect.get(orient.get_perpendicular()).low();
Interval rectIvl = nodep->rect.get(orient);
leadingEdges.push_back(EdgeAssociation(std::pair<Unit, Interval>(leading, rectIvl), nodep));
}
polygon_sort(leadingEdges.begin(), leadingEdges.end(), lessEdgeAssociation());
typename std::vector<EdgeAssociation>::iterator leadingBegin = leadingEdges.begin();
iT trailingBegin = beginNode;
while(leadingBegin != leadingEdges.end()) {
EdgeAssociation& leadingSegment = (*leadingBegin);
Unit trailing = (*trailingBegin).rect.get(orient.get_perpendicular()).high();
Interval ivl = (*trailingBegin).rect.get(orient);
std::pair<Unit, Interval> trailingSegment(trailing, ivl);
if(leadingSegment.first.first < trailingSegment.first) {
++leadingBegin;
continue;
}
if(leadingSegment.first.first > trailingSegment.first) {
++trailingBegin;
continue;
}
if(leadingSegment.first.second.high() <= trailingSegment.second.low()) {
++leadingBegin;
continue;
}
if(trailingSegment.second.high() <= leadingSegment.first.second.low()) {
++trailingBegin;
continue;
}
//leading segment intersects trailing segment
(*trailingBegin).add((*leadingBegin).second);
if(leadingSegment.first.second.high() > trailingSegment.second.high()) {
++trailingBegin;
continue;
}
if(trailingSegment.second.high() > leadingSegment.first.second.high()) {
++leadingBegin;
continue;
}
++leadingBegin;
++trailingBegin;
}
}
template <class cT>
static inline void getMaxCover(cT& outputContainer,
const std::vector<Rectangle>& rects, orientation_2d orient) {
if(rects.empty()) return;
std::vector<Node> nodes;
{
if(rects.size() == 1) {
outputContainer.push_back(copy_construct<typename cT::value_type, Rectangle>(rects[0]));
return;
}
nodes.reserve(rects.size());
for(std::size_t i = 0; i < rects.size(); ++i) { nodes.push_back(Node(rects[i])); }
}
computeDag(nodes.begin(), nodes.end(), orient, nodes.size());
for(std::size_t i = 0; i < nodes.size(); ++i) {
getMaxCover(outputContainer, &(nodes[i]), orient);
}
}
};
}
}
#endif