gmBVHAcceleration.h

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#ifndef _GEMA_BVHACCELERATION_H_
#define _GEMA_BVHACCELERATION_H_

// BVH includes
#include <bvh.h>
#include <vec.h>
#include <ray.h>
#include <node.h>
#include <default_builder.h>
#include <thread_pool.h>
#include <stack.h>
#include <tri.h>


#include <vector>


struct RayIntersection {
    double first[3];
    double last[3];
    int count;
};


class GmBVHAcceleration
{

    //BVH aliases for double and 3 geometry
    using Scalar = double;
    using Vec3 = bvh::Vec<Scalar, 3>;
    using BBox = bvh::BBox<Scalar, 3>;
    using Tri = bvh::Tri<Scalar, 3>;
    using Node = bvh::Node<Scalar, 3>;
    using Bvh = bvh::Bvh<Node>;
    using Ray = bvh::Ray<Scalar, 3>;
    using PrecomputedTri = bvh::PrecomputedTri<Scalar>;


private:

    Bvh bvh;
    std::vector<PrecomputedTri> preTri;

public:
    /*
    *  Constructor for BVH acceleration structure
    * 
    *    triCoords - [x1, y1, z1, .., xn, yn, zn]
    *    triIndex - [ t1_v1, t1_v2, t1_v3, ..., tm_v1, tm_v2, tm_v3]
    *    numPoints - N
    *    numTriangles - M
    *    threadPool - default (inefficient)
    */
    GmBVHAcceleration(const double* triCoords, const int* triIndex, int numPoints, int numTriangles, bvh::ThreadPool threadPool = bvh::ThreadPool());

    /*
     * Return true if the the segment given by 'start' and 'end' 
     * intersects any of the triangles and stores the intersection
     * point at 'intersection'
     */
    bool segIntersection(const double* start, const double* end, RayIntersection& ri);

private:
    
    void computeLinePoint(Vec3 p0, Vec3 dir, double t, double* out);
};
#endif