// Copyright 2009-2020 Intel Corporation
// SPDX-License-Identifier: Apache-2.0

#pragma once

#include "default.h"
#include "ray.h"
#include "point_query.h"
#include "context.h"

namespace embree
{
  class Scene;

  /*! Base class for the acceleration structure data. */
  class AccelData : public RefCount 
  {
    ALIGNED_CLASS_(16);
  public:
    enum Type { TY_UNKNOWN = 0, TY_ACCELN = 1, TY_ACCEL_INSTANCE = 2, TY_BVH4 = 3, TY_BVH8 = 4 };

  public:
    AccelData (const Type type) 
      : bounds(empty), type(type) {}

    /*! notifies the acceleration structure about the deletion of some geometry */
    virtual void deleteGeometry(size_t geomID) {};
   
    /*! clears the acceleration structure data */
    virtual void clear() = 0;

    /*! returns normal bounds */
    __forceinline BBox3fa getBounds() const {
      return bounds.bounds();
    }

    /*! returns bounds for some time */
    __forceinline BBox3fa getBounds(float t) const {
      return bounds.interpolate(t);
    }

    /*! returns linear bounds */
    __forceinline LBBox3fa getLinearBounds() const {
      return bounds;
    }

    /*! checks if acceleration structure is empty */
    __forceinline bool isEmpty() const {
      return bounds.bounds0.lower.x == float(pos_inf);
    }

  public:
    LBBox3fa bounds; // linear bounds
    Type type;
  };

  /*! Base class for all intersectable and buildable acceleration structures. */
  class Accel : public AccelData
  {
     ALIGNED_CLASS_(16);
  public:

    struct Intersectors;

    /*! Type of collide function */
    typedef void (*CollideFunc)(void* bvh0, void* bvh1, RTCCollideFunc callback, void* userPtr);

    /*! Type of point query function */
    typedef bool(*PointQueryFunc)(Intersectors* This,          /*!< this pointer to accel */
                                  PointQuery* query,        /*!< point query for lookup */
                                  PointQueryContext* context); /*!< point query context */

    /*! Type of intersect function pointer for single rays. */
    typedef void (*IntersectFunc)(Intersectors* This,  /*!< this pointer to accel */
                                  RTCRayHit& ray,      /*!< ray to intersect */
                                  IntersectContext* context);
    
    /*! Type of intersect function pointer for ray packets of size 4. */
    typedef void (*IntersectFunc4)(const void* valid,  /*!< pointer to valid mask */
                                   Intersectors* This, /*!< this pointer to accel */
                                   RTCRayHit4& ray,    /*!< ray packet to intersect */
                                   IntersectContext* context);
    
    /*! Type of intersect function pointer for ray packets of size 8. */
    typedef void (*IntersectFunc8)(const void* valid,  /*!< pointer to valid mask */
                                   Intersectors* This, /*!< this pointer to accel */
                                   RTCRayHit8& ray,    /*!< ray packet to intersect */
                                   IntersectContext* context);
    
    /*! Type of intersect function pointer for ray packets of size 16. */
    typedef void (*IntersectFunc16)(const void* valid,  /*!< pointer to valid mask */
                                    Intersectors* This, /*!< this pointer to accel */
                                    RTCRayHit16& ray,   /*!< ray packet to intersect */
                                    IntersectContext* context);

    /*! Type of intersect function pointer for ray packets of size N. */
    typedef void (*IntersectFuncN)(Intersectors* This, /*!< this pointer to accel */
                                   RTCRayHitN** ray,   /*!< ray stream to intersect */
                                   const size_t N,     /*!< number of rays in stream */
                                   IntersectContext* context /*!< layout flags */);
    
    
    /*! Type of occlusion function pointer for single rays. */
    typedef void (*OccludedFunc) (Intersectors* This, /*!< this pointer to accel */
                                  RTCRay& ray,        /*!< ray to test occlusion */
                                  IntersectContext* context);
    
    /*! Type of occlusion function pointer for ray packets of size 4. */
    typedef void (*OccludedFunc4) (const void* valid,  /*!< pointer to valid mask */
                                   Intersectors* This, /*!< this pointer to accel */
                                   RTCRay4& ray,       /*!< ray packet to test occlusion. */
                                   IntersectContext* context);
    
    /*! Type of occlusion function pointer for ray packets of size 8. */
    typedef void (*OccludedFunc8) (const void* valid,  /*!< pointer to valid mask */
                                   Intersectors* This, /*!< this pointer to accel */
                                   RTCRay8& ray,       /*!< ray packet to test occlusion. */
                                   IntersectContext* context);
    
    /*! Type of occlusion function pointer for ray packets of size 16. */
    typedef void (*OccludedFunc16) (const void* valid,  /*!< pointer to valid mask */
                                    Intersectors* This, /*!< this pointer to accel */
                                    RTCRay16& ray,      /*!< ray packet to test occlusion. */
                                    IntersectContext* context);

    /*! Type of intersect function pointer for ray packets of size N. */
    typedef void (*OccludedFuncN)(Intersectors* This, /*!< this pointer to accel */
                                  RTCRayN** ray,      /*!< ray stream to test occlusion */
                                  const size_t N,     /*!< number of rays in stream */
                                  IntersectContext* context /*!< layout flags */);
    typedef void (*ErrorFunc) ();

    struct Collider
    {
      Collider (ErrorFunc error = nullptr) 
      : collide((CollideFunc)error), name(nullptr) {}

      Collider (CollideFunc collide, const char* name)
      : collide(collide), name(name) {}

      operator bool() const { return name; }

    public:
      CollideFunc collide;  
      const char* name;
    };
    
    struct Intersector1
    {
      Intersector1 (ErrorFunc error = nullptr)
      : intersect((IntersectFunc)error), occluded((OccludedFunc)error), name(nullptr) {}
      
      Intersector1 (IntersectFunc intersect, OccludedFunc occluded, const char* name)
      : intersect(intersect), occluded(occluded), pointQuery(nullptr), name(name) {}
      
      Intersector1 (IntersectFunc intersect, OccludedFunc occluded, PointQueryFunc pointQuery, const char* name)
      : intersect(intersect), occluded(occluded), pointQuery(pointQuery), name(name) {}

      operator bool() const { return name; }

    public:
      static const char* type;
      IntersectFunc intersect;
      OccludedFunc occluded;
      PointQueryFunc pointQuery;
      const char* name;
    };
    
    struct Intersector4 
    {
      Intersector4 (ErrorFunc error = nullptr)
      : intersect((IntersectFunc4)error), occluded((OccludedFunc4)error), name(nullptr) {}

      Intersector4 (IntersectFunc4 intersect, OccludedFunc4 occluded, const char* name)
      : intersect(intersect), occluded(occluded), name(name) {}

      operator bool() const { return name; }
      
    public:
      static const char* type;
      IntersectFunc4 intersect;
      OccludedFunc4 occluded;
      const char* name;
    };
    
    struct Intersector8 
    {
      Intersector8 (ErrorFunc error = nullptr)
      : intersect((IntersectFunc8)error), occluded((OccludedFunc8)error), name(nullptr) {}

      Intersector8 (IntersectFunc8 intersect, OccludedFunc8 occluded, const char* name)
      : intersect(intersect), occluded(occluded), name(name) {}

      operator bool() const { return name; }
      
    public:
      static const char* type;
      IntersectFunc8 intersect;
      OccludedFunc8 occluded;
      const char* name;
    };
    
    struct Intersector16 
    {
      Intersector16 (ErrorFunc error = nullptr)
      : intersect((IntersectFunc16)error), occluded((OccludedFunc16)error), name(nullptr) {}

      Intersector16 (IntersectFunc16 intersect, OccludedFunc16 occluded, const char* name)
      : intersect(intersect), occluded(occluded), name(name) {}

      operator bool() const { return name; }
      
    public:
      static const char* type;
      IntersectFunc16 intersect;
      OccludedFunc16 occluded;
      const char* name;
    };

    struct IntersectorN 
    {
      IntersectorN (ErrorFunc error = nullptr)
      : intersect((IntersectFuncN)error), occluded((OccludedFuncN)error), name(nullptr) {}

      IntersectorN (IntersectFuncN intersect, OccludedFuncN occluded, const char* name)
      : intersect(intersect), occluded(occluded), name(name) {}

      operator bool() const { return name; }
      
    public:
      static const char* type;
      IntersectFuncN intersect;
      OccludedFuncN occluded;
      const char* name;
    };
   
    struct Intersectors 
    {
      Intersectors() 
      : ptr(nullptr), leafIntersector(nullptr), collider(nullptr), intersector1(nullptr), intersector4(nullptr), intersector8(nullptr), intersector16(nullptr), intersectorN(nullptr) {}

      Intersectors (ErrorFunc error) 
      : ptr(nullptr), leafIntersector(nullptr), collider(error), intersector1(error), intersector4(error), intersector8(error), intersector16(error), intersectorN(error) {}

      void print(size_t ident) 
      {
        if (collider.name) {
          for (size_t i=0; i<ident; i++) std::cout << " ";
          std::cout << "collider  = " << collider.name << std::endl;
        }
        if (intersector1.name) {
          for (size_t i=0; i<ident; i++) std::cout << " ";
          std::cout << "intersector1  = " << intersector1.name << std::endl;
        }
        if (intersector4.name) {
          for (size_t i=0; i<ident; i++) std::cout << " ";
          std::cout << "intersector4  = " << intersector4.name << std::endl;
        }
        if (intersector8.name) {
          for (size_t i=0; i<ident; i++) std::cout << " ";
          std::cout << "intersector8  = " << intersector8.name << std::endl;
        }
        if (intersector16.name) {
          for (size_t i=0; i<ident; i++) std::cout << " ";
          std::cout << "intersector16 = " << intersector16.name << std::endl;
        }
        if (intersectorN.name) {
          for (size_t i=0; i<ident; i++) std::cout << " ";
          std::cout << "intersectorN = " << intersectorN.name << std::endl;
        }        
      }

      void select(bool filter)
      {
        if (intersector4_filter) {
          if (filter) intersector4 = intersector4_filter;
          else        intersector4 = intersector4_nofilter;
        }
        if (intersector8_filter) {
          if (filter) intersector8 = intersector8_filter;
          else        intersector8 = intersector8_nofilter;
        }
        if (intersector16_filter) {
          if (filter) intersector16 = intersector16_filter;
          else         intersector16 = intersector16_nofilter;
        }
        if (intersectorN_filter) {
          if (filter) intersectorN = intersectorN_filter;
          else        intersectorN = intersectorN_nofilter;
        }        
      }

      __forceinline bool pointQuery (PointQuery* query, PointQueryContext* context) {
        assert(intersector1.pointQuery);
        return intersector1.pointQuery(this,query,context);
      }

      /*! collides two scenes */
      __forceinline void collide (Accel* scene0, Accel* scene1, RTCCollideFunc callback, void* userPtr) {
        assert(collider.collide);
        collider.collide(scene0->intersectors.ptr,scene1->intersectors.ptr,callback,userPtr);
      }

      /*! Intersects a single ray with the scene. */
      __forceinline void intersect (RTCRayHit& ray, IntersectContext* context) {
        assert(intersector1.intersect);
        intersector1.intersect(this,ray,context);
      }

      /*! Intersects a packet of 4 rays with the scene. */
      __forceinline void intersect4 (const void* valid, RTCRayHit4& ray, IntersectContext* context) {
        assert(intersector4.intersect);
        intersector4.intersect(valid,this,ray,context);
      }
      
      /*! Intersects a packet of 8 rays with the scene. */
      __forceinline void intersect8 (const void* valid, RTCRayHit8& ray, IntersectContext* context) {
        assert(intersector8.intersect);
        intersector8.intersect(valid,this,ray,context);
      }
      
      /*! Intersects a packet of 16 rays with the scene. */
      __forceinline void intersect16 (const void* valid, RTCRayHit16& ray, IntersectContext* context) {
        assert(intersector16.intersect);
        intersector16.intersect(valid,this,ray,context);
      }
      
      /*! Intersects a stream of N rays in SOA layout with the scene. */
      __forceinline void intersectN (RTCRayHitN** rayN, const size_t N, IntersectContext* context)
      {
        assert(intersectorN.intersect);
        intersectorN.intersect(this,rayN,N,context);
      }
      
#if defined(__SSE__) || defined(__ARM_NEON)
      __forceinline void intersect(const vbool4& valid, RayHitK<4>& ray, IntersectContext* context) {
        const vint<4> mask = valid.mask32();
        intersect4(&mask,(RTCRayHit4&)ray,context);
      }
#endif
#if defined(__AVX__)
      __forceinline void intersect(const vbool8& valid, RayHitK<8>& ray, IntersectContext* context) {
        const vint<8> mask = valid.mask32();
        intersect8(&mask,(RTCRayHit8&)ray,context);
      }
#endif
#if defined(__AVX512F__)
      __forceinline void intersect(const vbool16& valid, RayHitK<16>& ray, IntersectContext* context) {
        const vint<16> mask = valid.mask32();
        intersect16(&mask,(RTCRayHit16&)ray,context);
      }
#endif
      
      template<int K>
      __forceinline void intersectN (RayHitK<K>** rayN, const size_t N, IntersectContext* context)
      {
        intersectN((RTCRayHitN**)rayN,N,context);
      }

      /*! Tests if single ray is occluded by the scene. */
      __forceinline void occluded (RTCRay& ray, IntersectContext* context) {
        assert(intersector1.occluded);
        intersector1.occluded(this,ray,context);
      }
      
      /*! Tests if a packet of 4 rays is occluded by the scene. */
      __forceinline void occluded4 (const void* valid, RTCRay4& ray, IntersectContext* context) {
        assert(intersector4.occluded);
        intersector4.occluded(valid,this,ray,context);
      }
      
      /*! Tests if a packet of 8 rays is occluded by the scene. */
      __forceinline void occluded8 (const void* valid, RTCRay8& ray, IntersectContext* context) {
        assert(intersector8.occluded);
        intersector8.occluded(valid,this,ray,context);
      }
      
      /*! Tests if a packet of 16 rays is occluded by the scene. */
      __forceinline void occluded16 (const void* valid, RTCRay16& ray, IntersectContext* context) {
        assert(intersector16.occluded);
        intersector16.occluded(valid,this,ray,context);
      }
      
      /*! Tests if a stream of N rays in SOA layout is occluded by the scene. */
      __forceinline void occludedN (RTCRayN** rayN, const size_t N, IntersectContext* context)
      {
        assert(intersectorN.occluded);
        intersectorN.occluded(this,rayN,N,context);
      }
      
#if defined(__SSE__) || defined(__ARM_NEON)
      __forceinline void occluded(const vbool4& valid, RayK<4>& ray, IntersectContext* context) {
        const vint<4> mask = valid.mask32();
        occluded4(&mask,(RTCRay4&)ray,context);
      }
#endif
#if defined(__AVX__)
      __forceinline void occluded(const vbool8& valid, RayK<8>& ray, IntersectContext* context) {
        const vint<8> mask = valid.mask32();
        occluded8(&mask,(RTCRay8&)ray,context);
      }
#endif
#if defined(__AVX512F__)
      __forceinline void occluded(const vbool16& valid, RayK<16>& ray, IntersectContext* context) {
        const vint<16> mask = valid.mask32();
        occluded16(&mask,(RTCRay16&)ray,context);
      }
#endif

      template<int K>
      __forceinline void occludedN (RayK<K>** rayN, const size_t N, IntersectContext* context)
      {
        occludedN((RTCRayN**)rayN,N,context);
      }

      /*! Tests if single ray is occluded by the scene. */
      __forceinline void intersect(RTCRay& ray, IntersectContext* context) {
        occluded(ray, context);
      }

      /*! Tests if a packet of K rays is occluded by the scene. */
      template<int K>
      __forceinline void intersect(const vbool<K>& valid, RayK<K>& ray, IntersectContext* context) {
        occluded(valid, ray, context);
      }

      /*! Tests if a packet of N rays in SOA layout is occluded by the scene. */
      template<int K>
      __forceinline void intersectN(RayK<K>** rayN, const size_t N, IntersectContext* context) {
        occludedN(rayN, N, context);
      }
      
    public:
      AccelData* ptr;
      void* leafIntersector;
      Collider collider;
      Intersector1 intersector1;
      Intersector4 intersector4;
      Intersector4 intersector4_filter;
      Intersector4 intersector4_nofilter;
      Intersector8 intersector8;
      Intersector8 intersector8_filter;
      Intersector8 intersector8_nofilter;
      Intersector16 intersector16;
      Intersector16 intersector16_filter;
      Intersector16 intersector16_nofilter;
      IntersectorN intersectorN;
      IntersectorN intersectorN_filter;
      IntersectorN intersectorN_nofilter;      
    };
  
  public:

    /*! Construction */
    Accel (const AccelData::Type type) 
      : AccelData(type) {}
    
    /*! Construction */
    Accel (const AccelData::Type type, const Intersectors& intersectors) 
      : AccelData(type), intersectors(intersectors) {}

    /*! Virtual destructor */
    virtual ~Accel() {}

    /*! makes the acceleration structure immutable */
    virtual void immutable () {}
    
    /*! build acceleration structure */
    virtual void build () = 0;

  public:
    Intersectors intersectors;
  };

#define DEFINE_COLLIDER(symbol,collider)                                \
  Accel::Collider symbol() {                                            \
    return Accel::Collider((Accel::CollideFunc)collider::collide,       \
                           TOSTRING(isa) "::" TOSTRING(symbol));        \
  }

#define DEFINE_INTERSECTOR1(symbol,intersector)                               \
  Accel::Intersector1 symbol() {                                              \
    return Accel::Intersector1((Accel::IntersectFunc )intersector::intersect, \
                               (Accel::OccludedFunc  )intersector::occluded,  \
                               (Accel::PointQueryFunc)intersector::pointQuery,\
                               TOSTRING(isa) "::" TOSTRING(symbol));          \
  }
  
#define DEFINE_INTERSECTOR4(symbol,intersector)                               \
  Accel::Intersector4 symbol() {                                              \
    return Accel::Intersector4((Accel::IntersectFunc4)intersector::intersect, \
                               (Accel::OccludedFunc4)intersector::occluded,   \
                               TOSTRING(isa) "::" TOSTRING(symbol));          \
  }
  
#define DEFINE_INTERSECTOR8(symbol,intersector)                               \
  Accel::Intersector8 symbol() {                                              \
    return Accel::Intersector8((Accel::IntersectFunc8)intersector::intersect, \
                               (Accel::OccludedFunc8)intersector::occluded,   \
                               TOSTRING(isa) "::" TOSTRING(symbol));          \
  }

#define DEFINE_INTERSECTOR16(symbol,intersector)                                \
  Accel::Intersector16 symbol() {                                               \
    return Accel::Intersector16((Accel::IntersectFunc16)intersector::intersect, \
                                (Accel::OccludedFunc16)intersector::occluded,   \
                                TOSTRING(isa) "::" TOSTRING(symbol));           \
  }

#define DEFINE_INTERSECTORN(symbol,intersector)                               \
  Accel::IntersectorN symbol() {                                              \
    return Accel::IntersectorN((Accel::IntersectFuncN)intersector::intersect, \
                               (Accel::OccludedFuncN)intersector::occluded,   \
                               TOSTRING(isa) "::" TOSTRING(symbol));          \
  }

  /* ray stream filter interface */
  typedef void (*intersectStreamAOS_func)(Scene* scene, RTCRayHit*  _rayN, const size_t N, const size_t stride, IntersectContext* context);
  typedef void (*intersectStreamAOP_func)(Scene* scene, RTCRayHit** _rayN, const size_t N, IntersectContext* context);
  typedef void (*intersectStreamSOA_func)(Scene* scene, char* rayN, const size_t N, const size_t streams, const size_t stream_offset, IntersectContext* context);
  typedef void (*intersectStreamSOP_func)(Scene* scene, const RTCRayHitNp* rayN, const size_t N, IntersectContext* context);

  typedef void (*occludedStreamAOS_func)(Scene* scene, RTCRay*  _rayN, const size_t N, const size_t stride, IntersectContext* context);
  typedef void (*occludedStreamAOP_func)(Scene* scene, RTCRay** _rayN, const size_t N, IntersectContext* context);
  typedef void (*occludedStreamSOA_func)(Scene* scene, char* rayN, const size_t N, const size_t streams, const size_t stream_offset, IntersectContext* context);
  typedef void (*occludedStreamSOP_func)(Scene* scene, const RTCRayNp* rayN, const size_t N, IntersectContext* context);

  struct RayStreamFilterFuncs
  {
    RayStreamFilterFuncs()
    : intersectAOS(nullptr), intersectAOP(nullptr), intersectSOA(nullptr), intersectSOP(nullptr),
      occludedAOS(nullptr),  occludedAOP(nullptr),  occludedSOA(nullptr),  occludedSOP(nullptr) {}

    RayStreamFilterFuncs(void (*ptr) ())
    : intersectAOS((intersectStreamAOS_func) ptr), intersectAOP((intersectStreamAOP_func) ptr), intersectSOA((intersectStreamSOA_func) ptr), intersectSOP((intersectStreamSOP_func) ptr),
      occludedAOS((occludedStreamAOS_func) ptr),   occludedAOP((occludedStreamAOP_func) ptr),   occludedSOA((occludedStreamSOA_func) ptr),   occludedSOP((occludedStreamSOP_func) ptr) {}

    RayStreamFilterFuncs(intersectStreamAOS_func intersectAOS, intersectStreamAOP_func intersectAOP, intersectStreamSOA_func intersectSOA, intersectStreamSOP_func intersectSOP,
                         occludedStreamAOS_func  occludedAOS,  occludedStreamAOP_func  occludedAOP,  occludedStreamSOA_func  occludedSOA,  occludedStreamSOP_func  occludedSOP)
    : intersectAOS(intersectAOS), intersectAOP(intersectAOP), intersectSOA(intersectSOA), intersectSOP(intersectSOP),
      occludedAOS(occludedAOS),   occludedAOP(occludedAOP),   occludedSOA(occludedSOA),   occludedSOP(occludedSOP) {}

  public:
    intersectStreamAOS_func intersectAOS;
    intersectStreamAOP_func intersectAOP;
    intersectStreamSOA_func intersectSOA;
    intersectStreamSOP_func intersectSOP;

    occludedStreamAOS_func occludedAOS;
    occludedStreamAOP_func occludedAOP;
    occludedStreamSOA_func occludedSOA;
    occludedStreamSOP_func occludedSOP;
  }; 

  typedef RayStreamFilterFuncs (*RayStreamFilterFuncsType)();
}