415 lines
15 KiB
C++
415 lines
15 KiB
C++
// Copyright 2009-2021 Intel Corporation
|
|
// SPDX-License-Identifier: Apache-2.0
|
|
|
|
#pragma once
|
|
|
|
#include "../common/scene.h"
|
|
#include "priminfo.h"
|
|
|
|
namespace embree
|
|
{
|
|
static const unsigned int RESERVED_NUM_SPATIAL_SPLITS_GEOMID_BITS = 5;
|
|
|
|
namespace isa
|
|
{
|
|
|
|
/*! mapping into bins */
|
|
template<size_t BINS>
|
|
struct SpatialBinMapping
|
|
{
|
|
public:
|
|
__forceinline SpatialBinMapping() {}
|
|
|
|
/*! calculates the mapping */
|
|
__forceinline SpatialBinMapping(const CentGeomBBox3fa& pinfo)
|
|
{
|
|
const vfloat4 lower = (vfloat4) pinfo.geomBounds.lower;
|
|
const vfloat4 upper = (vfloat4) pinfo.geomBounds.upper;
|
|
const vfloat4 eps = 128.0f*vfloat4(ulp)*max(abs(lower),abs(upper));
|
|
const vfloat4 diag = max(eps,(vfloat4) pinfo.geomBounds.size());
|
|
scale = select(upper-lower <= eps,vfloat4(0.0f),vfloat4(BINS)/diag);
|
|
ofs = (vfloat4) pinfo.geomBounds.lower;
|
|
inv_scale = 1.0f / scale;
|
|
}
|
|
|
|
/*! slower but safe binning */
|
|
__forceinline vint4 bin(const Vec3fa& p) const
|
|
{
|
|
const vint4 i = floori((vfloat4(p)-ofs)*scale);
|
|
return clamp(i,vint4(0),vint4(BINS-1));
|
|
}
|
|
|
|
__forceinline std::pair<vint4,vint4> bin(const BBox3fa& b) const
|
|
{
|
|
#if defined(__AVX__)
|
|
const vfloat8 ofs8(ofs);
|
|
const vfloat8 scale8(scale);
|
|
const vint8 lu = floori((vfloat8::loadu(&b)-ofs8)*scale8);
|
|
const vint8 c_lu = clamp(lu,vint8(zero),vint8(BINS-1));
|
|
return std::pair<vint4,vint4>(extract4<0>(c_lu),extract4<1>(c_lu));
|
|
#else
|
|
const vint4 lower = floori((vfloat4(b.lower)-ofs)*scale);
|
|
const vint4 upper = floori((vfloat4(b.upper)-ofs)*scale);
|
|
const vint4 c_lower = clamp(lower,vint4(0),vint4(BINS-1));
|
|
const vint4 c_upper = clamp(upper,vint4(0),vint4(BINS-1));
|
|
return std::pair<vint4,vint4>(c_lower,c_upper);
|
|
#endif
|
|
}
|
|
|
|
|
|
/*! calculates left spatial position of bin */
|
|
__forceinline float pos(const size_t bin, const size_t dim) const {
|
|
return madd(float(bin),inv_scale[dim],ofs[dim]);
|
|
}
|
|
|
|
/*! calculates left spatial position of bin */
|
|
template<size_t N>
|
|
__forceinline vfloat<N> posN(const vfloat<N> bin, const size_t dim) const {
|
|
return madd(bin,vfloat<N>(inv_scale[dim]),vfloat<N>(ofs[dim]));
|
|
}
|
|
|
|
/*! returns true if the mapping is invalid in some dimension */
|
|
__forceinline bool invalid(const size_t dim) const {
|
|
return scale[dim] == 0.0f;
|
|
}
|
|
|
|
public:
|
|
vfloat4 ofs,scale,inv_scale; //!< linear function that maps to bin ID
|
|
};
|
|
|
|
/*! stores all information required to perform some split */
|
|
template<size_t BINS>
|
|
struct SpatialBinSplit
|
|
{
|
|
/*! construct an invalid split by default */
|
|
__forceinline SpatialBinSplit()
|
|
: sah(inf), dim(-1), pos(0), left(-1), right(-1), factor(1.0f) {}
|
|
|
|
/*! constructs specified split */
|
|
__forceinline SpatialBinSplit(float sah, int dim, int pos, const SpatialBinMapping<BINS>& mapping)
|
|
: sah(sah), dim(dim), pos(pos), left(-1), right(-1), factor(1.0f), mapping(mapping) {}
|
|
|
|
/*! constructs specified split */
|
|
__forceinline SpatialBinSplit(float sah, int dim, int pos, int left, int right, float factor, const SpatialBinMapping<BINS>& mapping)
|
|
: sah(sah), dim(dim), pos(pos), left(left), right(right), factor(factor), mapping(mapping) {}
|
|
|
|
/*! tests if this split is valid */
|
|
__forceinline bool valid() const { return dim != -1; }
|
|
|
|
/*! calculates surface area heuristic for performing the split */
|
|
__forceinline float splitSAH() const { return sah; }
|
|
|
|
/*! stream output */
|
|
friend embree_ostream operator<<(embree_ostream cout, const SpatialBinSplit& split) {
|
|
return cout << "SpatialBinSplit { sah = " << split.sah << ", dim = " << split.dim << ", pos = " << split.pos << ", left = " << split.left << ", right = " << split.right << ", factor = " << split.factor << "}";
|
|
}
|
|
|
|
public:
|
|
float sah; //!< SAH cost of the split
|
|
int dim; //!< split dimension
|
|
int pos; //!< split position
|
|
int left; //!< number of elements on the left side
|
|
int right; //!< number of elements on the right side
|
|
float factor; //!< factor splitting the extended range
|
|
SpatialBinMapping<BINS> mapping; //!< mapping into bins
|
|
};
|
|
|
|
/*! stores all binning information */
|
|
template<size_t BINS, typename PrimRef>
|
|
struct __aligned(64) SpatialBinInfo
|
|
{
|
|
SpatialBinInfo() {
|
|
}
|
|
|
|
__forceinline SpatialBinInfo(EmptyTy) {
|
|
clear();
|
|
}
|
|
|
|
/*! clears the bin info */
|
|
__forceinline void clear()
|
|
{
|
|
for (size_t i=0; i<BINS; i++) {
|
|
bounds[i][0] = bounds[i][1] = bounds[i][2] = empty;
|
|
numBegin[i] = numEnd[i] = 0;
|
|
}
|
|
}
|
|
|
|
/*! adds binning data */
|
|
__forceinline void add(const size_t dim,
|
|
const size_t beginID,
|
|
const size_t endID,
|
|
const size_t binID,
|
|
const BBox3fa &b,
|
|
const size_t n = 1)
|
|
{
|
|
assert(beginID < BINS);
|
|
assert(endID < BINS);
|
|
assert(binID < BINS);
|
|
|
|
numBegin[beginID][dim]+=(unsigned int)n;
|
|
numEnd [endID][dim]+=(unsigned int)n;
|
|
bounds [binID][dim].extend(b);
|
|
}
|
|
|
|
/*! extends binning bounds */
|
|
__forceinline void extend(const size_t dim,
|
|
const size_t binID,
|
|
const BBox3fa &b)
|
|
{
|
|
assert(binID < BINS);
|
|
bounds [binID][dim].extend(b);
|
|
}
|
|
|
|
/*! bins an array of triangles */
|
|
template<typename SplitPrimitive>
|
|
__forceinline void bin(const SplitPrimitive& splitPrimitive, const PrimRef* prims, size_t N, const SpatialBinMapping<BINS>& mapping)
|
|
{
|
|
for (size_t i=0; i<N; i++)
|
|
{
|
|
const PrimRef prim = prims[i];
|
|
unsigned splits = prim.geomID() >> (32-RESERVED_NUM_SPATIAL_SPLITS_GEOMID_BITS);
|
|
|
|
if (unlikely(splits == 1))
|
|
{
|
|
const vint4 bin = mapping.bin(center(prim.bounds()));
|
|
for (size_t dim=0; dim<3; dim++)
|
|
{
|
|
assert(bin[dim] >= (int)0 && bin[dim] < (int)BINS);
|
|
numBegin[bin[dim]][dim]++;
|
|
numEnd [bin[dim]][dim]++;
|
|
bounds [bin[dim]][dim].extend(prim.bounds());
|
|
}
|
|
}
|
|
else
|
|
{
|
|
const vint4 bin0 = mapping.bin(prim.bounds().lower);
|
|
const vint4 bin1 = mapping.bin(prim.bounds().upper);
|
|
|
|
for (size_t dim=0; dim<3; dim++)
|
|
{
|
|
size_t bin;
|
|
PrimRef rest = prim;
|
|
size_t l = bin0[dim];
|
|
size_t r = bin1[dim];
|
|
|
|
// same bin optimization
|
|
if (likely(l == r))
|
|
{
|
|
numBegin[l][dim]++;
|
|
numEnd [l][dim]++;
|
|
bounds [l][dim].extend(prim.bounds());
|
|
continue;
|
|
}
|
|
|
|
for (bin=(size_t)bin0[dim]; bin<(size_t)bin1[dim]; bin++)
|
|
{
|
|
const float pos = mapping.pos(bin+1,dim);
|
|
|
|
PrimRef left,right;
|
|
splitPrimitive(rest,(int)dim,pos,left,right);
|
|
if (unlikely(left.bounds().empty())) l++;
|
|
bounds[bin][dim].extend(left.bounds());
|
|
rest = right;
|
|
}
|
|
if (unlikely(rest.bounds().empty())) r--;
|
|
numBegin[l][dim]++;
|
|
numEnd [r][dim]++;
|
|
bounds [bin][dim].extend(rest.bounds());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*! bins a range of primitives inside an array */
|
|
template<typename SplitPrimitive>
|
|
void bin(const SplitPrimitive& splitPrimitive, const PrimRef* prims, size_t begin, size_t end, const SpatialBinMapping<BINS>& mapping) {
|
|
bin(splitPrimitive,prims+begin,end-begin,mapping);
|
|
}
|
|
|
|
/*! bins an array of primitives */
|
|
template<typename PrimitiveSplitterFactory>
|
|
__forceinline void bin2(const PrimitiveSplitterFactory& splitterFactory, const PrimRef* source, size_t begin, size_t end, const SpatialBinMapping<BINS>& mapping)
|
|
{
|
|
for (size_t i=begin; i<end; i++)
|
|
{
|
|
const PrimRef &prim = source[i];
|
|
const vint4 bin0 = mapping.bin(prim.bounds().lower);
|
|
const vint4 bin1 = mapping.bin(prim.bounds().upper);
|
|
|
|
for (size_t dim=0; dim<3; dim++)
|
|
{
|
|
if (unlikely(mapping.invalid(dim)))
|
|
continue;
|
|
|
|
size_t bin;
|
|
size_t l = bin0[dim];
|
|
size_t r = bin1[dim];
|
|
|
|
// same bin optimization
|
|
if (likely(l == r))
|
|
{
|
|
add(dim,l,l,l,prim.bounds());
|
|
continue;
|
|
}
|
|
const size_t bin_start = bin0[dim];
|
|
const size_t bin_end = bin1[dim];
|
|
BBox3fa rest = prim.bounds();
|
|
const auto splitter = splitterFactory(prim);
|
|
for (bin=bin_start; bin<bin_end; bin++)
|
|
{
|
|
const float pos = mapping.pos(bin+1,dim);
|
|
BBox3fa left,right;
|
|
splitter(rest,dim,pos,left,right);
|
|
if (unlikely(left.empty())) l++;
|
|
extend(dim,bin,left);
|
|
rest = right;
|
|
}
|
|
if (unlikely(rest.empty())) r--;
|
|
add(dim,l,r,bin,rest);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/*! bins an array of primitives */
|
|
__forceinline void binSubTreeRefs(const PrimRef* source, size_t begin, size_t end, const SpatialBinMapping<BINS>& mapping)
|
|
{
|
|
for (size_t i=begin; i<end; i++)
|
|
{
|
|
const PrimRef &prim = source[i];
|
|
const vint4 bin0 = mapping.bin(prim.bounds().lower);
|
|
const vint4 bin1 = mapping.bin(prim.bounds().upper);
|
|
|
|
for (size_t dim=0; dim<3; dim++)
|
|
{
|
|
if (unlikely(mapping.invalid(dim)))
|
|
continue;
|
|
|
|
const size_t l = bin0[dim];
|
|
const size_t r = bin1[dim];
|
|
|
|
const unsigned int n = prim.primID();
|
|
|
|
// same bin optimization
|
|
if (likely(l == r))
|
|
{
|
|
add(dim,l,l,l,prim.bounds(),n);
|
|
continue;
|
|
}
|
|
const size_t bin_start = bin0[dim];
|
|
const size_t bin_end = bin1[dim];
|
|
for (size_t bin=bin_start; bin<bin_end; bin++)
|
|
add(dim,l,r,bin,prim.bounds(),n);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*! merges in other binning information */
|
|
void merge (const SpatialBinInfo& other)
|
|
{
|
|
for (size_t i=0; i<BINS; i++)
|
|
{
|
|
numBegin[i] += other.numBegin[i];
|
|
numEnd [i] += other.numEnd [i];
|
|
bounds[i][0].extend(other.bounds[i][0]);
|
|
bounds[i][1].extend(other.bounds[i][1]);
|
|
bounds[i][2].extend(other.bounds[i][2]);
|
|
}
|
|
}
|
|
|
|
/*! merges in other binning information */
|
|
static __forceinline const SpatialBinInfo reduce (const SpatialBinInfo& a, const SpatialBinInfo& b)
|
|
{
|
|
SpatialBinInfo c(empty);
|
|
for (size_t i=0; i<BINS; i++)
|
|
{
|
|
c.numBegin[i] += a.numBegin[i]+b.numBegin[i];
|
|
c.numEnd [i] += a.numEnd [i]+b.numEnd [i];
|
|
c.bounds[i][0] = embree::merge(a.bounds[i][0],b.bounds[i][0]);
|
|
c.bounds[i][1] = embree::merge(a.bounds[i][1],b.bounds[i][1]);
|
|
c.bounds[i][2] = embree::merge(a.bounds[i][2],b.bounds[i][2]);
|
|
}
|
|
return c;
|
|
}
|
|
|
|
/*! finds the best split by scanning binning information */
|
|
SpatialBinSplit<BINS> best(const SpatialBinMapping<BINS>& mapping, const size_t blocks_shift) const
|
|
{
|
|
/* sweep from right to left and compute parallel prefix of merged bounds */
|
|
vfloat4 rAreas[BINS];
|
|
vuint4 rCounts[BINS];
|
|
vuint4 count = 0; BBox3fa bx = empty; BBox3fa by = empty; BBox3fa bz = empty;
|
|
for (size_t i=BINS-1; i>0; i--)
|
|
{
|
|
count += numEnd[i];
|
|
rCounts[i] = count;
|
|
bx.extend(bounds[i][0]); rAreas[i][0] = halfArea(bx);
|
|
by.extend(bounds[i][1]); rAreas[i][1] = halfArea(by);
|
|
bz.extend(bounds[i][2]); rAreas[i][2] = halfArea(bz);
|
|
rAreas[i][3] = 0.0f;
|
|
}
|
|
|
|
/* sweep from left to right and compute SAH */
|
|
vuint4 blocks_add = (1 << blocks_shift)-1;
|
|
vuint4 ii = 1; vfloat4 vbestSAH = pos_inf; vuint4 vbestPos = 0; vuint4 vbestlCount = 0; vuint4 vbestrCount = 0;
|
|
count = 0; bx = empty; by = empty; bz = empty;
|
|
for (size_t i=1; i<BINS; i++, ii+=1)
|
|
{
|
|
count += numBegin[i-1];
|
|
bx.extend(bounds[i-1][0]); float Ax = halfArea(bx);
|
|
by.extend(bounds[i-1][1]); float Ay = halfArea(by);
|
|
bz.extend(bounds[i-1][2]); float Az = halfArea(bz);
|
|
const vfloat4 lArea = vfloat4(Ax,Ay,Az,Az);
|
|
const vfloat4 rArea = rAreas[i];
|
|
const vuint4 lCount = (count +blocks_add) >> (unsigned int)(blocks_shift);
|
|
const vuint4 rCount = (rCounts[i]+blocks_add) >> (unsigned int)(blocks_shift);
|
|
const vfloat4 sah = madd(lArea,vfloat4(lCount),rArea*vfloat4(rCount));
|
|
// const vfloat4 sah = madd(lArea,vfloat4(vint4(lCount)),rArea*vfloat4(vint4(rCount)));
|
|
const vbool4 mask = sah < vbestSAH;
|
|
vbestPos = select(mask,ii ,vbestPos);
|
|
vbestSAH = select(mask,sah,vbestSAH);
|
|
vbestlCount = select(mask,count,vbestlCount);
|
|
vbestrCount = select(mask,rCounts[i],vbestrCount);
|
|
}
|
|
|
|
/* find best dimension */
|
|
float bestSAH = inf;
|
|
int bestDim = -1;
|
|
int bestPos = 0;
|
|
unsigned int bestlCount = 0;
|
|
unsigned int bestrCount = 0;
|
|
for (int dim=0; dim<3; dim++)
|
|
{
|
|
/* ignore zero sized dimensions */
|
|
if (unlikely(mapping.invalid(dim)))
|
|
continue;
|
|
|
|
/* test if this is a better dimension */
|
|
if (vbestSAH[dim] < bestSAH && vbestPos[dim] != 0) {
|
|
bestDim = dim;
|
|
bestPos = vbestPos[dim];
|
|
bestSAH = vbestSAH[dim];
|
|
bestlCount = vbestlCount[dim];
|
|
bestrCount = vbestrCount[dim];
|
|
}
|
|
}
|
|
assert(bestSAH >= 0.0f);
|
|
|
|
/* return invalid split if no split found */
|
|
if (bestDim == -1)
|
|
return SpatialBinSplit<BINS>(inf,-1,0,mapping);
|
|
|
|
/* return best found split */
|
|
return SpatialBinSplit<BINS>(bestSAH,bestDim,bestPos,bestlCount,bestrCount,1.0f,mapping);
|
|
}
|
|
|
|
private:
|
|
BBox3fa bounds[BINS][3]; //!< geometry bounds for each bin in each dimension
|
|
vuint4 numBegin[BINS]; //!< number of primitives starting in bin
|
|
vuint4 numEnd[BINS]; //!< number of primitives ending in bin
|
|
};
|
|
}
|
|
}
|
|
|