1 files changed, 95 insertions, 0 deletions
diff --git a/thirdparty/embree/kernels/bvh/bvh_refit.h b/thirdparty/embree/kernels/bvh/bvh_refit.h
new file mode 100644
index 0000000000..09bb3d8da5
--- /dev/null
+++ b/thirdparty/embree/kernels/bvh/bvh_refit.h
@@ -0,0 +1,95 @@
+// Copyright 2009-2021 Intel Corporation
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include "../bvh/bvh.h"
+
+namespace embree
+{
+  namespace isa
+  {
+    template<int N>
+    class BVHNRefitter
+    {
+    public:
+
+      /*! Type shortcuts */
+      typedef BVHN<N> BVH;
+      typedef typename BVH::AABBNode AABBNode;
+      typedef typename BVH::NodeRef NodeRef;
+
+      struct LeafBoundsInterface {
+        virtual const BBox3fa leafBounds(NodeRef& ref) const = 0;
+      };
+
+    public:
+    
+      /*! Constructor. */
+      BVHNRefitter (BVH* bvh, const LeafBoundsInterface& leafBounds);
+
+      /*! refits the BVH */
+      void refit();
+
+    private:
+      /* single-threaded subtree extraction based on BVH depth */
+      void gather_subtree_refs(NodeRef& ref, 
+                               size_t &subtrees,
+                               const size_t depth = 0);
+
+      /* single-threaded top-level refit */
+      BBox3fa refit_toplevel(NodeRef& ref,
+                             size_t &subtrees,
+							 const BBox3fa *const subTreeBounds,
+                             const size_t depth = 0);
+
+      /* single-threaded subtree refit */
+      BBox3fa recurse_bottom(NodeRef& ref);
+      
+    public:
+      BVH* bvh;                              //!< BVH to refit
+      const LeafBoundsInterface& leafBounds; //!< calculates bounds of leaves
+
+      static const size_t MAX_SUB_TREE_EXTRACTION_DEPTH = (N==4) ? 4   : (N==8) ? 3    : 3;
+      static const size_t MAX_NUM_SUB_TREES             = (N==4) ? 256 : (N==8) ? 512 : N*N*N; // N ^ MAX_SUB_TREE_EXTRACTION_DEPTH
+      size_t numSubTrees;
+      NodeRef subTrees[MAX_NUM_SUB_TREES];
+    };
+
+    template<int N, typename Mesh, typename Primitive>
+    class BVHNRefitT : public Builder, public BVHNRefitter<N>::LeafBoundsInterface
+    {
+    public:
+      
+      /*! Type shortcuts */
+      typedef BVHN<N> BVH;
+      typedef typename BVH::AABBNode AABBNode;
+      typedef typename BVH::NodeRef NodeRef;
+      
+    public:
+      BVHNRefitT (BVH* bvh, Builder* builder, Mesh* mesh, size_t mode);
+
+      virtual void build();
+      
+      virtual void clear();
+
+      virtual const BBox3fa leafBounds (NodeRef& ref) const
+      {
+        size_t num; char* prim = ref.leaf(num);
+        if (unlikely(ref == BVH::emptyNode)) return empty;
+
+        BBox3fa bounds = empty;
+        for (size_t i=0; i<num; i++)
+            bounds.extend(((Primitive*)prim)[i].update(mesh));
+        return bounds;
+      }
+      
+    private:
+      BVH* bvh;
+      std::unique_ptr<Builder> builder;
+      std::unique_ptr<BVHNRefitter<N>> refitter;
+      Mesh* mesh;
+      unsigned int topologyVersion;
+    };
+  }
+}