godot/thirdparty/embree/kernels/builders/heuristic_timesplit_array.h

238 lines
9.8 KiB
C++

// Copyright 2009-2021 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include "../common/primref_mb.h"
#include "../../common/algorithms/parallel_filter.h"
#define MBLUR_TIME_SPLIT_THRESHOLD 1.25f
namespace embree
{
namespace isa
{
/*! Performs standard object binning */
template<typename PrimRefMB, typename RecalculatePrimRef, size_t BINS>
struct HeuristicMBlurTemporalSplit
{
typedef BinSplit<MBLUR_NUM_OBJECT_BINS> Split;
typedef mvector<PrimRefMB>* PrimRefVector;
typedef typename PrimRefMB::BBox BBox;
static const size_t PARALLEL_THRESHOLD = 3 * 1024;
static const size_t PARALLEL_FIND_BLOCK_SIZE = 1024;
static const size_t PARALLEL_PARTITION_BLOCK_SIZE = 128;
HeuristicMBlurTemporalSplit (MemoryMonitorInterface* device, const RecalculatePrimRef& recalculatePrimRef)
: device(device), recalculatePrimRef(recalculatePrimRef) {}
struct TemporalBinInfo
{
__forceinline TemporalBinInfo () {
}
__forceinline TemporalBinInfo (EmptyTy)
{
for (size_t i=0; i<BINS-1; i++)
{
count0[i] = count1[i] = 0;
bounds0[i] = bounds1[i] = empty;
}
}
void bin(const PrimRefMB* prims, size_t begin, size_t end, BBox1f time_range, const SetMB& set, const RecalculatePrimRef& recalculatePrimRef)
{
for (int b=0; b<BINS-1; b++)
{
const float t = float(b+1)/float(BINS);
const float ct = lerp(time_range.lower,time_range.upper,t);
const float center_time = set.align_time(ct);
if (center_time <= time_range.lower) continue;
if (center_time >= time_range.upper) continue;
const BBox1f dt0(time_range.lower,center_time);
const BBox1f dt1(center_time,time_range.upper);
/* find linear bounds for both time segments */
for (size_t i=begin; i<end; i++)
{
if (prims[i].time_range_overlap(dt0))
{
const LBBox3fa bn0 = recalculatePrimRef.linearBounds(prims[i],dt0);
#if MBLUR_BIN_LBBOX
bounds0[b].extend(bn0);
#else
bounds0[b].extend(bn0.interpolate(0.5f));
#endif
count0[b] += prims[i].timeSegmentRange(dt0).size();
}
if (prims[i].time_range_overlap(dt1))
{
const LBBox3fa bn1 = recalculatePrimRef.linearBounds(prims[i],dt1);
#if MBLUR_BIN_LBBOX
bounds1[b].extend(bn1);
#else
bounds1[b].extend(bn1.interpolate(0.5f));
#endif
count1[b] += prims[i].timeSegmentRange(dt1).size();
}
}
}
}
__forceinline void bin_parallel(const PrimRefMB* prims, size_t begin, size_t end, size_t blockSize, size_t parallelThreshold, BBox1f time_range, const SetMB& set, const RecalculatePrimRef& recalculatePrimRef)
{
if (likely(end-begin < parallelThreshold)) {
bin(prims,begin,end,time_range,set,recalculatePrimRef);
}
else
{
auto bin = [&](const range<size_t>& r) -> TemporalBinInfo {
TemporalBinInfo binner(empty); binner.bin(prims, r.begin(), r.end(), time_range, set, recalculatePrimRef); return binner;
};
*this = parallel_reduce(begin,end,blockSize,TemporalBinInfo(empty),bin,merge2);
}
}
/*! merges in other binning information */
__forceinline void merge (const TemporalBinInfo& other)
{
for (size_t i=0; i<BINS-1; i++)
{
count0[i] += other.count0[i];
count1[i] += other.count1[i];
bounds0[i].extend(other.bounds0[i]);
bounds1[i].extend(other.bounds1[i]);
}
}
static __forceinline const TemporalBinInfo merge2(const TemporalBinInfo& a, const TemporalBinInfo& b) {
TemporalBinInfo r = a; r.merge(b); return r;
}
Split best(int logBlockSize, BBox1f time_range, const SetMB& set)
{
float bestSAH = inf;
float bestPos = 0.0f;
for (int b=0; b<BINS-1; b++)
{
float t = float(b+1)/float(BINS);
float ct = lerp(time_range.lower,time_range.upper,t);
const float center_time = set.align_time(ct);
if (center_time <= time_range.lower) continue;
if (center_time >= time_range.upper) continue;
const BBox1f dt0(time_range.lower,center_time);
const BBox1f dt1(center_time,time_range.upper);
/* calculate sah */
const size_t lCount = (count0[b]+(size_t(1) << logBlockSize)-1) >> int(logBlockSize);
const size_t rCount = (count1[b]+(size_t(1) << logBlockSize)-1) >> int(logBlockSize);
float sah0 = expectedApproxHalfArea(bounds0[b])*float(lCount)*dt0.size();
float sah1 = expectedApproxHalfArea(bounds1[b])*float(rCount)*dt1.size();
if (unlikely(lCount == 0)) sah0 = 0.0f; // happens for initial splits when objects not alive over entire shutter time
if (unlikely(rCount == 0)) sah1 = 0.0f;
const float sah = sah0+sah1;
if (sah < bestSAH) {
bestSAH = sah;
bestPos = center_time;
}
}
return Split(bestSAH*MBLUR_TIME_SPLIT_THRESHOLD,(unsigned)Split::SPLIT_TEMPORAL,0,bestPos);
}
public:
size_t count0[BINS-1];
size_t count1[BINS-1];
BBox bounds0[BINS-1];
BBox bounds1[BINS-1];
};
/*! finds the best split */
const Split find(const SetMB& set, const size_t logBlockSize)
{
assert(set.size() > 0);
TemporalBinInfo binner(empty);
binner.bin_parallel(set.prims->data(),set.begin(),set.end(),PARALLEL_FIND_BLOCK_SIZE,PARALLEL_THRESHOLD,set.time_range,set,recalculatePrimRef);
Split tsplit = binner.best((int)logBlockSize,set.time_range,set);
if (!tsplit.valid()) tsplit.data = Split::SPLIT_FALLBACK; // use fallback split
return tsplit;
}
__forceinline std::unique_ptr<mvector<PrimRefMB>> split(const Split& tsplit, const SetMB& set, SetMB& lset, SetMB& rset)
{
assert(tsplit.sah != float(inf));
assert(tsplit.fpos > set.time_range.lower);
assert(tsplit.fpos < set.time_range.upper);
float center_time = tsplit.fpos;
const BBox1f time_range0(set.time_range.lower,center_time);
const BBox1f time_range1(center_time,set.time_range.upper);
mvector<PrimRefMB>& prims = *set.prims;
/* calculate primrefs for first time range */
std::unique_ptr<mvector<PrimRefMB>> new_vector(new mvector<PrimRefMB>(device, set.size()));
PrimRefVector lprims = new_vector.get();
auto reduction_func0 = [&] (const range<size_t>& r) {
PrimInfoMB pinfo = empty;
for (size_t i=r.begin(); i<r.end(); i++)
{
if (likely(prims[i].time_range_overlap(time_range0)))
{
const PrimRefMB& prim = recalculatePrimRef(prims[i],time_range0);
(*lprims)[i-set.begin()] = prim;
pinfo.add_primref(prim);
}
else
{
(*lprims)[i-set.begin()] = prims[i];
}
}
return pinfo;
};
PrimInfoMB linfo = parallel_reduce(set.object_range,PARALLEL_PARTITION_BLOCK_SIZE,PARALLEL_THRESHOLD,PrimInfoMB(empty),reduction_func0,PrimInfoMB::merge2);
/* primrefs for first time range are in lprims[0 .. set.size()) */
/* some primitives may need to be filtered out */
if (linfo.size() != set.size())
linfo.object_range._end = parallel_filter(lprims->data(), size_t(0), set.size(), size_t(1024),
[&](const PrimRefMB& prim) { return prim.time_range_overlap(time_range0); });
lset = SetMB(linfo,lprims,time_range0);
/* calculate primrefs for second time range */
auto reduction_func1 = [&] (const range<size_t>& r) {
PrimInfoMB pinfo = empty;
for (size_t i=r.begin(); i<r.end(); i++)
{
if (likely(prims[i].time_range_overlap(time_range1)))
{
const PrimRefMB& prim = recalculatePrimRef(prims[i],time_range1);
prims[i] = prim;
pinfo.add_primref(prim);
}
}
return pinfo;
};
PrimInfoMB rinfo = parallel_reduce(set.object_range,PARALLEL_PARTITION_BLOCK_SIZE,PARALLEL_THRESHOLD,PrimInfoMB(empty),reduction_func1,PrimInfoMB::merge2);
rinfo.object_range = range<size_t>(set.begin(), set.begin() + rinfo.size());
/* primrefs for second time range are in prims[set.begin() .. set.end()) */
/* some primitives may need to be filtered out */
if (rinfo.size() != set.size())
rinfo.object_range._end = parallel_filter(prims.data(), set.begin(), set.end(), size_t(1024),
[&](const PrimRefMB& prim) { return prim.time_range_overlap(time_range1); });
rset = SetMB(rinfo,&prims,time_range1);
return new_vector;
}
private:
MemoryMonitorInterface* device; // device to report memory usage to
const RecalculatePrimRef recalculatePrimRef;
};
}
}