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OpenSpace/modules/globebrowsing/geometry/convexhull.h

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3.4 KiB
C++

/*****************************************************************************************
* *
* OpenSpace *
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* Copyright (c) 2014-2016 *
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* Permission is hereby granted, free of charge, to any person obtaining a copy of this *
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#ifndef __CONVEX_HULL_H__
#define __CONVEX_HULL_H__
#include <modules/globebrowsing/geometry/aabb.h>
#include <vector>
#include <stack>
#include <memory>
#include <glm/glm.hpp>
// open space includes
namespace openspace {
using namespace glm;
// Implementation based on
// http://www.sanfoundry.com/cpp-program-implement-graham-scan-algorithm-find-convex-hull/
typedef glm::vec2 Point2;
class ConvexHull2 {
public:
ConvexHull2();
static ConvexHull2 grahamScan_NOT_THREAD_SAFE(std::vector<Point2>& points, int yMinIndex = -1);
const std::vector<Point2> points() const;
bool intersects(const ConvexHull2& o) const;
AABB1 projectedRegion(glm::vec2 direction) const;
private:
bool hasPerpendicularLineWhereProjectedPointsOverlap(const ConvexHull2& other) const;
static int compare(const void *vp1, const void *vp2);
static Point2 oneBelowTop(std::stack<Point2>&);
static void swap(Point2& p1, Point2& p2);
// returns 0 = colinear, 1 = clockwise, 2 = counterclockwise
static int orientation(const Point2& p, const Point2& q, const Point2& r);
static float dist(const Point2& p1, const Point2& p2);
private:
static Point2 p0;
std::vector<Point2> _points;
};
} // namespace openspace
#endif // __CONVEX_HULL_H__