ExtUtilities.h

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#ifndef EXT_TET_CPU_BVH_H
#define EXT_TET_CPU_BVH_H
 
#include "foundation/PxArray.h"
 
#include "foundation/PxBounds3.h"
 
#include "GuBVH.h"
#include "GuAABBTree.h"
#include "GuAABBTreeNode.h"
#include "GuAABBTreeBounds.h"
#include "GuAABBTreeQuery.h"
#include "GuTriangle.h"
#include "ExtVec3.h"
 
namespace physx
{
namespace Ext
{
    using Triangle = Gu::IndexedTriangleT<PxI32>;
 
    //Creates an unique 64bit bit key out of two 32bit values, the key is order independent, useful as hash key for edges
    //Use this functions to compute the edge keys used in the edgesToSplit parameter of the split function below.
    PX_FORCE_INLINE PxU64 key(PxI32 a, PxI32 b)
    {
        if (a < b)
            return ((PxU64(a)) << 32) | (PxU64(b));
        else
            return ((PxU64(b)) << 32) | (PxU64(a));
    }
 
    void buildTree(const PxU32* triangles, const PxU32 numTriangles, const Vec3* points, PxArray<Gu::BVHNode>& tree, PxF32 enlargement = 1e-4f);
    
    //Builds a BVH from a set of triangles
    PX_FORCE_INLINE void buildTree(const PxArray<Triangle>& triangles, const PxArray<Vec3>& points, PxArray<Gu::BVHNode>& tree, PxF32 enlargement = 1e-4f)
    {
        buildTree(reinterpret_cast<const PxU32*>(triangles.begin()), triangles.size(), points.begin(), tree, enlargement);
    }
 
    template<typename T>
    void traverseBVH(const PxArray<Gu::BVHNode>& nodes, T& traversalController, PxI32 rootNodeIndex = 0)
    {
        traverseBVH(nodes.begin(), traversalController, rootNodeIndex);
    }
 
    class IntersectionCollectingTraversalController
    {
        PxBounds3 box;
        PxArray<PxI32>& candidateTriangleIndices;
 
    public:
        IntersectionCollectingTraversalController(PxArray<PxI32>& candidateTriangleIndices_) :
            box(PxBounds3::empty()), candidateTriangleIndices(candidateTriangleIndices_)
        { }
 
        IntersectionCollectingTraversalController(const PxBounds3& box_, PxArray<PxI32>& candidateTriangleIndices_) : 
            box(box_), candidateTriangleIndices(candidateTriangleIndices_)
        { }
 
        void reset(const PxBounds3& box_)
        {
            box = box_;
            candidateTriangleIndices.clear();
        }
 
        Gu::TraversalControl::Enum analyze(const Gu::BVHNode& node, PxI32)
        {
            if (node.isLeaf())
            {
                candidateTriangleIndices.pushBack(node.getPrimitiveIndex());
                return Gu::TraversalControl::eDontGoDeeper;
            }
 
            if (node.mBV.intersects(box))
                return Gu::TraversalControl::eGoDeeper;
            return Gu::TraversalControl::eDontGoDeeper;
        }
    private:
        PX_NOCOPY(IntersectionCollectingTraversalController)
    };
}
}
#endif