1 // Copyright 2009-2021 Intel Corporation
2 // SPDX-License-Identifier: Apache-2.0
3 
4 #include "bvh.h"
5 #include "bvh_statistics.h"
6 
7 namespace embree
8 {
9   template<int N>
BVHN(const PrimitiveType & primTy,Scene * scene)10   BVHN<N>::BVHN (const PrimitiveType& primTy, Scene* scene)
11     : AccelData((N==4) ? AccelData::TY_BVH4 : (N==8) ? AccelData::TY_BVH8 : AccelData::TY_UNKNOWN),
12       primTy(&primTy), device(scene->device), scene(scene),
13       root(emptyNode), alloc(scene->device,scene->isStaticAccel()), numPrimitives(0), numVertices(0)
14   {
15   }
16 
17   template<int N>
~BVHN()18   BVHN<N>::~BVHN ()
19   {
20     for (size_t i=0; i<objects.size(); i++)
21       delete objects[i];
22   }
23 
24   template<int N>
clear()25   void BVHN<N>::clear()
26   {
27     set(BVHN::emptyNode,empty,0);
28     alloc.clear();
29   }
30 
31   template<int N>
set(NodeRef root,const LBBox3fa & bounds,size_t numPrimitives)32   void BVHN<N>::set (NodeRef root, const LBBox3fa& bounds, size_t numPrimitives)
33   {
34     this->root = root;
35     this->bounds = bounds;
36     this->numPrimitives = numPrimitives;
37   }
38 
39   template<int N>
clearBarrier(NodeRef & node)40   void BVHN<N>::clearBarrier(NodeRef& node)
41   {
42     if (node.isBarrier())
43       node.clearBarrier();
44     else if (!node.isLeaf()) {
45       BaseNode* n = node.baseNode(); // FIXME: flags should be stored in BVH
46       for (size_t c=0; c<N; c++)
47         clearBarrier(n->child(c));
48     }
49   }
50 
51   template<int N>
layoutLargeNodes(size_t num)52   void BVHN<N>::layoutLargeNodes(size_t num)
53   {
54 #if defined(__64BIT__) // do not use tree rotations on 32 bit platforms, barrier bit in NodeRef will cause issues
55     struct NodeArea
56     {
57       __forceinline NodeArea() {}
58 
59       __forceinline NodeArea(NodeRef& node, const BBox3fa& bounds)
60         : node(&node), A(node.isLeaf() ? float(neg_inf) : area(bounds)) {}
61 
62       __forceinline bool operator< (const NodeArea& other) const {
63         return this->A < other.A;
64       }
65 
66       NodeRef* node;
67       float A;
68     };
69     std::vector<NodeArea> lst;
70     lst.reserve(num);
71     lst.push_back(NodeArea(root,empty));
72 
73     while (lst.size() < num)
74     {
75       std::pop_heap(lst.begin(), lst.end());
76       NodeArea n = lst.back(); lst.pop_back();
77       if (!n.node->isAABBNode()) break;
78       AABBNode* node = n.node->getAABBNode();
79       for (size_t i=0; i<N; i++) {
80         if (node->child(i) == BVHN::emptyNode) continue;
81         lst.push_back(NodeArea(node->child(i),node->bounds(i)));
82         std::push_heap(lst.begin(), lst.end());
83       }
84     }
85 
86     for (size_t i=0; i<lst.size(); i++)
87       lst[i].node->setBarrier();
88 
89     root = layoutLargeNodesRecursion(root,alloc.getCachedAllocator());
90 #endif
91   }
92 
93   template<int N>
layoutLargeNodesRecursion(NodeRef & node,const FastAllocator::CachedAllocator & allocator)94   typename BVHN<N>::NodeRef BVHN<N>::layoutLargeNodesRecursion(NodeRef& node, const FastAllocator::CachedAllocator& allocator)
95   {
96     if (node.isBarrier()) {
97       node.clearBarrier();
98       return node;
99     }
100     else if (node.isAABBNode())
101     {
102       AABBNode* oldnode = node.getAABBNode();
103       AABBNode* newnode = (BVHN::AABBNode*) allocator.malloc0(sizeof(BVHN::AABBNode),byteNodeAlignment);
104       *newnode = *oldnode;
105       for (size_t c=0; c<N; c++)
106         newnode->child(c) = layoutLargeNodesRecursion(oldnode->child(c),allocator);
107       return encodeNode(newnode);
108     }
109     else return node;
110   }
111 
112   template<int N>
preBuild(const std::string & builderName)113   double BVHN<N>::preBuild(const std::string& builderName)
114   {
115     if (builderName == "")
116       return inf;
117 
118     if (device->verbosity(2))
119     {
120       Lock<MutexSys> lock(g_printMutex);
121       std::cout << "building BVH" << N << (builderName.find("MBlur") != std::string::npos ? "MB" : "") << "<" << primTy->name() << "> using " << builderName << " ..." << std::endl << std::flush;
122     }
123 
124     double t0 = 0.0;
125     if (device->benchmark || device->verbosity(2)) t0 = getSeconds();
126     return t0;
127   }
128 
129   template<int N>
postBuild(double t0)130   void BVHN<N>::postBuild(double t0)
131   {
132     if (t0 == double(inf))
133       return;
134 
135     double dt = 0.0;
136     if (device->benchmark || device->verbosity(2))
137       dt = getSeconds()-t0;
138 
139     std::unique_ptr<BVHNStatistics<N>> stat;
140 
141     /* print statistics */
142     if (device->verbosity(2))
143     {
144       if (!stat) stat.reset(new BVHNStatistics<N>(this));
145       const size_t usedBytes = alloc.getUsedBytes();
146       Lock<MutexSys> lock(g_printMutex);
147       std::cout << "finished BVH" << N << "<" << primTy->name() << "> : " << 1000.0f*dt << "ms, " << 1E-6*double(numPrimitives)/dt << " Mprim/s, " << 1E-9*double(usedBytes)/dt << " GB/s" << std::endl;
148 
149       if (device->verbosity(2))
150         std::cout << stat->str();
151 
152       if (device->verbosity(2))
153       {
154         FastAllocator::AllStatistics stat(&alloc);
155         for (size_t i=0; i<objects.size(); i++)
156           if (objects[i])
157             stat = stat + FastAllocator::AllStatistics(&objects[i]->alloc);
158 
159         stat.print(numPrimitives);
160       }
161 
162       if (device->verbosity(3))
163       {
164         alloc.print_blocks();
165         for (size_t i=0; i<objects.size(); i++)
166           if (objects[i])
167             objects[i]->alloc.print_blocks();
168       }
169 
170       std::cout << std::flush;
171     }
172 
173     /* benchmark mode */
174     if (device->benchmark)
175     {
176       if (!stat) stat.reset(new BVHNStatistics<N>(this));
177       Lock<MutexSys> lock(g_printMutex);
178       std::cout << "BENCHMARK_BUILD " << dt << " " << double(numPrimitives)/dt << " " << stat->sah() << " " << stat->bytesUsed() << " BVH" << N << "<" << primTy->name() << ">" << std::endl << std::flush;
179     }
180   }
181 
182 #if defined(__AVX__)
183   template class BVHN<8>;
184 #endif
185 
186 #if !defined(__AVX__) || !defined(EMBREE_TARGET_SSE2) && !defined(EMBREE_TARGET_SSE42)
187   template class BVHN<4>;
188 #endif
189 }
190 
191