godot/thirdparty/embree/kernels/builders/primrefgen_presplit.h

// Copyright 2009-2021 Intel Corporation
// SPDX-License-Identifier: Apache-2.0

#pragma once

#include "../../common/algorithms/parallel_reduce.h"
#include "../../common/algorithms/parallel_sort.h"
#include "../builders/heuristic_spatial.h"
#include "../builders/splitter.h"

#include "../../common/algorithms/parallel_partition.h"
#include "../../common/algorithms/parallel_for_for.h"
#include "../../common/algorithms/parallel_for_for_prefix_sum.h"

#define DBG_PRESPLIT(x) …   
#define CHECK_PRESPLIT(x) … 

#define GRID_SIZE …
//#define MAX_PRESPLITS_PER_PRIMITIVE_LOG 6
#define MAX_PRESPLITS_PER_PRIMITIVE_LOG …
#define MAX_PRESPLITS_PER_PRIMITIVE …
//#define PRIORITY_CUTOFF_THRESHOLD 2.0f
#define PRIORITY_SPLIT_POS_WEIGHT …

namespace embree
{  
  namespace isa
  {
    struct SplittingGrid
    { … };

    struct PresplitItem
    { … };

    inline std::ostream &operator<<(std::ostream &cout, const PresplitItem& item) {
      return cout << "index " << item.index << " priority " << item.priority;    
    };

#if 1
    
    template<typename Splitter>    
      void splitPrimitive(const Splitter& splitter,
                          const PrimRef& prim,
                          const unsigned int splitprims,
                          const SplittingGrid& grid,
                          PrimRef subPrims[MAX_PRESPLITS_PER_PRIMITIVE],
                          unsigned int& numSubPrims)
    { … }

#else
    
    template<typename Splitter>    
      void splitPrimitive(const Splitter& splitter,
                          const PrimRef& prim,
                          const unsigned int targetSubPrims,
                          const SplittingGrid& grid,
                          PrimRef subPrims[MAX_PRESPLITS_PER_PRIMITIVE],
                          unsigned int& numSubPrims)
    {
      assert(targetSubPrims > 0 && targetSubPrims <= MAX_PRESPLITS_PER_PRIMITIVE);
      
      auto compare = [] ( const PrimRef& a, const PrimRef& b ) {
        return area(a.bounds()) < area(b.bounds());
      };
      
      subPrims[numSubPrims++] = prim;

      while (numSubPrims < targetSubPrims)
      {
        /* get top heap element */
        std::pop_heap(subPrims+0,subPrims+numSubPrims, compare);
        PrimRef top = subPrims[--numSubPrims];

        unsigned int dim; float fsplit;
        if (!grid.split_pos(top, dim, fsplit))
        {
          assert(numSubPrims < MAX_PRESPLITS_PER_PRIMITIVE);
          subPrims[numSubPrims++] = top;
          return;
        }
          
        /* split primitive */
        PrimRef left,right;
        splitter(top,dim,fsplit,left,right);
        assert(!left.bounds().empty());
        assert(!right.bounds().empty());

        subPrims[numSubPrims++] = left;
        std::push_heap(subPrims+0, subPrims+numSubPrims, compare);

        subPrims[numSubPrims++] = right;
        std::push_heap(subPrims+0, subPrims+numSubPrims, compare);
      }
    }
    
#endif

#if !defined(RTHWIF_STANDALONE)

    template<typename Mesh, typename SplitterFactory>    
      PrimInfo createPrimRefArray_presplit(Geometry* geometry, unsigned int geomID, size_t numPrimRefs, mvector<PrimRef>& prims, BuildProgressMonitor& progressMonitor)
    { … }
#endif
    
    template<typename SplitPrimitiveFunc, typename ProjectedPrimitiveAreaFunc, typename PrimVector>
    PrimInfo createPrimRefArray_presplit(size_t numPrimRefs,
                                         PrimVector& prims,
                                         const PrimInfo& pinfo,
                                         const SplitPrimitiveFunc& splitPrimitive,
                                         const ProjectedPrimitiveAreaFunc& primitiveArea)
    { … }

#if !defined(RTHWIF_STANDALONE)
    
     template<typename Mesh, typename SplitterFactory>    
      PrimInfo createPrimRefArray_presplit(Scene* scene, Geometry::GTypeMask types, bool mblur, size_t numPrimRefs, mvector<PrimRef>& prims, BuildProgressMonitor& progressMonitor)
    { … }
#endif 
  }
}