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#ifndef RDP_HPP__
#define RDP_HPP__
#include <QBitArray>
#include <QPair>
#include <QPolygonF>
#include <QStack>
class RDP {
// This gets called approximately 10 times per second, and until
// the associated view resizes, it's going to need exactly the
// same amount of stack and tracking array as it did last time.
// Throwing that away and requesting it again every 100ms isn't
// ideal, which is why this is a functor instead of a function.
QStack<QPair<qsizetype, qsizetype>> stack;
QBitArray array;
public:
// Process the provided polygon through the Ramer–Douglas–Peucker
// algorithm at the requested epsilon level, modifying it in-place
// and returning an iterator suitable for erase-remove idiom usage,
// e.g.,
//
// QPolygonF polygon;
// RDP rdp;
//
// polygon.erase(rdp(polygon), polygon.end());
//
// Essentially, this acts the same as a std::remove_if() predicate
// does; points to retain are moved to the range [begin, iterator),
// while points to be elided are in the tail range [iterator, end].
// As the polygon remains the same size, the length of the tail is
// the number of elided points, and as with std::remove_if(), these
// points exist in memory but in an unspecified state.
QPolygonF::iterator operator()(QPolygonF &polygon, qreal epsilon = 2.0);
};
#endif
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