blender/intern/cycles/bvh/bvh.h
Ton Roosendaal da376e0237 Cycles render engine, initial commit. This is the engine itself, blender modifications and build instructions will follow later.
Cycles uses code from some great open source projects, many thanks them:

* BVH building and traversal code from NVidia's "Understanding the Efficiency of Ray Traversal on GPUs":
http://code.google.com/p/understanding-the-efficiency-of-ray-traversal-on-gpus/
* Open Shading Language for a large part of the shading system:
http://code.google.com/p/openshadinglanguage/
* Blender for procedural textures and a few other nodes.
* Approximate Catmull Clark subdivision from NVidia Mesh tools:
http://code.google.com/p/nvidia-mesh-tools/
* Sobol direction vectors from:
http://web.maths.unsw.edu.au/~fkuo/sobol/
* Film response functions from:
http://www.cs.columbia.edu/CAVE/software/softlib/dorf.php
2011-04-27 11:58:34 +00:00

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/*
* Adapted from code copyright 2009-2010 NVIDIA Corporation
* Modifications Copyright 2011, Blender Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __BVH_H__
#define __BVH_H__
#include "bvh_params.h"
#include "util_types.h"
#include "util_vector.h"
CCL_NAMESPACE_BEGIN
class BVHNode;
class BVHStackEntry;
class BVHParams;
class BoundBox;
class CacheData;
class LeafNode;
class Object;
class Progress;
#define BVH_NODE_SIZE 4
#define BVH_QNODE_SIZE 8
#define BVH_ALIGN 4096
#define TRI_NODE_SIZE 3
/* Packed BVH
*
* BVH stored as it will be used for traversal on the rendering device. */
struct PackedBVH {
/* BVH nodes storage, one node is 4x int4, and contains two bounding boxes,
and child, triangle or object indexes dependening on the node type */
array<int4> nodes;
/* object index to BVH node index mapping for instances */
array<int> object_node;
/* precomputed triangle intersection data, one triangle is 4x float4 */
array<float4> tri_woop;
/* mapping from BVH primitive index to true primitive index, as primitives
may be duplicated due to spatial splits. -1 for instances. */
array<int> prim_index;
/* mapping from BVH primitive index, to the object id of that primitive. */
array<int> prim_object;
/* quick array to lookup if a node is a leaf, not used for traversal, only
for instance BVH merging */
array<int> is_leaf;
/* index of the root node. */
int root_index;
/* surface area heuristic, for building top level BVH */
float SAH;
PackedBVH()
{
root_index = 0;
SAH = 0.0f;
}
};
/* BVH */
class BVH
{
public:
PackedBVH pack;
BVHParams params;
vector<Object*> objects;
static BVH *create(const BVHParams& params, const vector<Object*>& objects);
void build(Progress& progress);
void refit(Progress& progress);
protected:
BVH(const BVHParams& params, const vector<Object*>& objects);
/* cache */
bool cache_read(CacheData& key);
void cache_write(CacheData& key);
/* triangles */
void pack_triangles();
void pack_triangle(int idx, float4 woop[3]);
/* merge instance BVH's */
void pack_instances(size_t nodes_size);
/* for subclasses to implement */
virtual void pack_nodes(const array<int>& prims, const BVHNode *root) = 0;
virtual void refit_nodes() = 0;
};
/* Regular BVH
*
* Typical BVH with each node having two children. */
class RegularBVH : public BVH {
protected:
/* constructor */
friend class BVH;
RegularBVH(const BVHParams& params, const vector<Object*>& objects);
/* pack */
void pack_nodes(const array<int>& prims, const BVHNode *root);
void pack_leaf(const BVHStackEntry& e, const LeafNode *leaf);
void pack_inner(const BVHStackEntry& e, const BVHStackEntry& e0, const BVHStackEntry& e1);
void pack_node(int idx, const BoundBox& b0, const BoundBox& b1, int c0, int c1);
/* refit */
void refit_nodes();
void refit_node(int idx, bool leaf, BoundBox& bbox);
};
/* QBVH
*
* Quad BVH, with each node having four children, to use with SIMD instructions. */
class QBVH : public BVH {
protected:
/* constructor */
friend class BVH;
QBVH(const BVHParams& params, const vector<Object*>& objects);
/* pack */
void pack_nodes(const array<int>& prims, const BVHNode *root);
void pack_leaf(const BVHStackEntry& e, const LeafNode *leaf);
void pack_inner(const BVHStackEntry& e, const BVHStackEntry *en, int num);
/* refit */
void refit_nodes();
};
CCL_NAMESPACE_END
#endif /* __BVH_H__ */