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#ifndef NVBLASTEXTTRIANGLEPROCESSOR_H
#define NVBLASTEXTTRIANGLEPROCESSOR_H

#include <PxVec2.h>
#include <PxVec3.h>
#include <vector>
#include <algorithm>

using namespace physx;


namespace Nv
{
namespace Blast
{

/**
    Triangle processor internal triangle representation. Contains only vertex positions.
*/
struct TrPrcTriangle
{
	PxVec3 points[3];
	TrPrcTriangle(PxVec3 a = PxVec3(0.0f), PxVec3 b = PxVec3(0.0f), PxVec3 c = PxVec3(0.0f))
	{
		points[0] = a;
		points[1] = b;
		points[2] = c;
	}

	TrPrcTriangle& operator=(const TrPrcTriangle& b)
	{
		points[0] = b.points[0];
		points[1] = b.points[1];
		points[2] = b.points[2];
		return *this;
	}

	TrPrcTriangle(const TrPrcTriangle& b)
	{
		points[0] = b.points[0];
		points[1] = b.points[1];
		points[2] = b.points[2];
	}
	PxVec3 getNormal() const
	{
		return (points[1] - points[0]).cross(points[2] - points[0]);
	}
};

/**
    Triangle processor internal 2D triangle representation. Contains only vertex positions.
*/
struct TrPrcTriangle2d
{
	PxVec2 points[3];
	TrPrcTriangle2d(PxVec2 a = PxVec2(0.0f), PxVec2 b = PxVec2(0.0f), PxVec2 c = PxVec2(0.0f))
	{
		points[0] = a;
		points[1] = b;
		points[2] = c;
	}

	TrPrcTriangle2d operator=(const TrPrcTriangle2d& b)
	{
		points[0] = b.points[0];
		points[1] = b.points[1];
		points[2] = b.points[2];
		return *this;
	}

	TrPrcTriangle2d(const TrPrcTriangle2d& b)
	{
		points[0] = b.points[0];
		points[1] = b.points[1];
		points[2] = b.points[2];
	}
};

class TriangleProcessor
{
  public:
	TriangleProcessor(){};
	~TriangleProcessor() {}


	/**
	    Build intersection between two triangles
	    \param[in] a			First triangle (A)
	    \param[in] aProjected	Projected triangle A
	    \param[in] b			Second triangle (B)
	    \param[in] centroid		Centroid of first triangle (A)
	    \param[out] intersectionBuffer Result intersection polygon
	    \param[in] normal		Normal vector to triangle (Common for both A and B).
	    \return 1 - if if intersection is found.
	*/
	uint32_t getTriangleIntersection(TrPrcTriangle& a, TrPrcTriangle2d& aProjected, TrPrcTriangle& b, PxVec3& centroid,
	                                 std::vector<PxVec3>& intersectionBuffer, PxVec3 normal);

	/**
	    Test whether BB of triangles intersect.
	    \param[in] a			First triangle (A)
	    \param[in] b			Second triangle (B)
	    \return true - if intersect
	*/
	bool triangleBoundingBoxIntersection(TrPrcTriangle2d& a, TrPrcTriangle2d& b);


	/**
	    Test whether point is inside of triangle.
	    \param[in] point		Point coordinates in 2d space.
	    \param[in] triangle		Triangle in 2d space.
	    \return 1 - if inside, 2 if on edge, 0 if neither inside nor edge.
	*/
	uint32_t isPointInside(const PxVec2& point, const TrPrcTriangle2d& triangle);

	/**
	    Segment intersection point
	    \param[in] s1 Segment-1 start point
	    \param[in] e1 Segment-1 end point
	    \param[in] s2 Segment-2 start point
	    \param[in] e2 Segment-2 end point
	    \param[out] t1 Intersection point parameter relatively to Segment-1, lies in [0.0, 1.0] range.
	    \return 0 if there is no intersections, 1 - if intersection is found.
	*/
	uint32_t getSegmentIntersection(const PxVec2& s1, const PxVec2& e1, const PxVec2& s2, const PxVec2& e2, PxF32& t1);

	/**
	    Sort vertices of polygon in CCW-order
	*/
	void sortToCCW(std::vector<PxVec3>& points, PxVec3& normal);

	/**
	    Builds convex polygon for given set of points. Points should be coplanar.
	    \param[in] points Input array of points
	    \param[out] convexHull Output polygon
	    \param[in] normal Normal vector to polygon.
	*/
	void buildConvexHull(std::vector<PxVec3>& points, std::vector<PxVec3>& convexHull, const PxVec3& normal);
};

}  // namespace Blast
}  // namespace Nv


#endif  // NVBLASTEXTTRIANGLEPROCESSOR_H