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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_SPLIT_H__
#define __BVH_SPLIT_H__
#include "bvh/build.h"
#include "bvh/params.h"
CCL_NAMESPACE_BEGIN
class BVHBuild;
class Hair;
class Mesh;
struct Transform;
/* Object Split */
class BVHObjectSplit {
public:
float sah;
int dim;
int num_left;
BoundBox left_bounds;
BoundBox right_bounds;
BVHObjectSplit()
{
}
BVHObjectSplit(BVHBuild *builder,
BVHSpatialStorage *storage,
const BVHRange &range,
vector<BVHReference> &references,
float nodeSAH,
const BVHUnaligned *unaligned_heuristic = NULL,
const Transform *aligned_space = NULL);
void split(BVHRange &left, BVHRange &right, const BVHRange &range);
protected:
BVHSpatialStorage *storage_;
vector<BVHReference> *references_;
const BVHUnaligned *unaligned_heuristic_;
const Transform *aligned_space_;
__forceinline BoundBox get_prim_bounds(const BVHReference &prim) const
{
if (aligned_space_ == NULL) {
return prim.bounds();
}
else {
return unaligned_heuristic_->compute_aligned_prim_boundbox(prim, *aligned_space_);
}
}
};
/* Spatial Split */
class BVHSpatialSplit {
public:
float sah;
int dim;
float pos;
BVHSpatialSplit() : sah(FLT_MAX), dim(0), pos(0.0f), storage_(NULL), references_(NULL)
{
}
BVHSpatialSplit(const BVHBuild &builder,
BVHSpatialStorage *storage,
const BVHRange &range,
vector<BVHReference> &references,
float nodeSAH,
const BVHUnaligned *unaligned_heuristic = NULL,
const Transform *aligned_space = NULL);
void split(BVHBuild *builder, BVHRange &left, BVHRange &right, const BVHRange &range);
void split_reference(const BVHBuild &builder,
BVHReference &left,
BVHReference &right,
const BVHReference &ref,
int dim,
float pos);
protected:
BVHSpatialStorage *storage_;
vector<BVHReference> *references_;
const BVHUnaligned *unaligned_heuristic_;
const Transform *aligned_space_;
/* Lower-level functions which calculates boundaries of left and right nodes
* needed for spatial split.
*
* Operates directly with primitive specified by its index, reused by higher
* level splitting functions.
*/
void split_triangle_primitive(const Mesh *mesh,
const Transform *tfm,
int prim_index,
int dim,
float pos,
BoundBox &left_bounds,
BoundBox &right_bounds);
void split_curve_primitive(const Hair *hair,
const Transform *tfm,
int prim_index,
int segment_index,
int dim,
float pos,
BoundBox &left_bounds,
BoundBox &right_bounds);
/* Lower-level functions which calculates boundaries of left and right nodes
* needed for spatial split.
*
* Operates with BVHReference, internally uses lower level API functions.
*/
void split_triangle_reference(const BVHReference &ref,
const Mesh *mesh,
int dim,
float pos,
BoundBox &left_bounds,
BoundBox &right_bounds);
void split_curve_reference(const BVHReference &ref,
const Hair *hair,
int dim,
float pos,
BoundBox &left_bounds,
BoundBox &right_bounds);
void split_object_reference(
const Object *object, int dim, float pos, BoundBox &left_bounds, BoundBox &right_bounds);
__forceinline BoundBox get_prim_bounds(const BVHReference &prim) const
{
if (aligned_space_ == NULL) {
return prim.bounds();
}
else {
return unaligned_heuristic_->compute_aligned_prim_boundbox(prim, *aligned_space_);
}
}
__forceinline float3 get_unaligned_point(const float3 &point) const
{
if (aligned_space_ == NULL) {
return point;
}
else {
return transform_point(aligned_space_, point);
}
}
};
/* Mixed Object-Spatial Split */
class BVHMixedSplit {
public:
BVHObjectSplit object;
BVHSpatialSplit spatial;
float leafSAH;
float nodeSAH;
float minSAH;
bool no_split;
BoundBox bounds;
BVHMixedSplit()
{
}
__forceinline BVHMixedSplit(BVHBuild *builder,
BVHSpatialStorage *storage,
const BVHRange &range,
vector<BVHReference> &references,
int level,
const BVHUnaligned *unaligned_heuristic = NULL,
const Transform *aligned_space = NULL)
{
if (aligned_space == NULL) {
bounds = range.bounds();
}
else {
bounds = unaligned_heuristic->compute_aligned_boundbox(
range, &references.at(0), *aligned_space);
}
/* find split candidates. */
float area = bounds.safe_area();
leafSAH = area * builder->params.primitive_cost(range.size());
nodeSAH = area * builder->params.node_cost(2);
object = BVHObjectSplit(
builder, storage, range, references, nodeSAH, unaligned_heuristic, aligned_space);
if (builder->params.use_spatial_split && level < BVHParams::MAX_SPATIAL_DEPTH) {
BoundBox overlap = object.left_bounds;
overlap.intersect(object.right_bounds);
if (overlap.safe_area() >= builder->spatial_min_overlap) {
spatial = BVHSpatialSplit(
*builder, storage, range, references, nodeSAH, unaligned_heuristic, aligned_space);
}
}
/* leaf SAH is the lowest => create leaf. */
minSAH = min(min(leafSAH, object.sah), spatial.sah);
no_split = (minSAH == leafSAH && builder->range_within_max_leaf_size(range, references));
}
__forceinline void split(BVHBuild *builder,
BVHRange &left,
BVHRange &right,
const BVHRange &range)
{
if (builder->params.use_spatial_split && minSAH == spatial.sah)
spatial.split(builder, left, right, range);
if (!left.size() || !right.size())
object.split(left, right, range);
}
};
CCL_NAMESPACE_END
#endif /* __BVH_SPLIT_H__ */
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