godot/thirdparty/embree/kernels/builders/heuristic_binning.h
Jakub Mateusz Marcowski c43eab55a4
embree: Update to 4.3.1
2024-03-27 22:10:35 +01:00

553 lines
23 KiB
C++

// Copyright 2009-2021 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include "priminfo.h"
#include "priminfo_mb.h"
#include "../../common/algorithms/parallel_reduce.h"
#include "../../common/algorithms/parallel_partition.h"
namespace embree
{
namespace isa
{
/*! mapping into bins */
template<size_t BINS>
struct BinMapping
{
public:
__forceinline BinMapping() {}
/*! calculates the mapping */
__forceinline BinMapping(size_t N, const BBox3fa& centBounds)
{
num = min(BINS,size_t(4.0f + 0.05f*N));
assert(num >= 1);
const vfloat4 eps = 1E-34f;
const vfloat4 diag = max(eps, (vfloat4) centBounds.size());
scale = select(diag > eps,vfloat4(0.99f*num)/diag,vfloat4(0.0f));
ofs = (vfloat4) centBounds.lower;
}
/*! calculates the mapping */
__forceinline BinMapping(const BBox3fa& centBounds)
{
num = BINS;
const vfloat4 eps = 1E-34f;
const vfloat4 diag = max(eps, (vfloat4) centBounds.size());
scale = select(diag > eps,vfloat4(0.99f*num)/diag,vfloat4(0.0f));
ofs = (vfloat4) centBounds.lower;
}
/*! calculates the mapping */
template<typename PrimInfo>
__forceinline BinMapping(const PrimInfo& pinfo)
{
const vfloat4 eps = 1E-34f;
num = min(BINS,size_t(4.0f + 0.05f*pinfo.size()));
const vfloat4 diag = max(eps,(vfloat4) pinfo.centBounds.size());
scale = select(diag > eps,vfloat4(0.99f*num)/diag,vfloat4(0.0f));
ofs = (vfloat4) pinfo.centBounds.lower;
}
/*! returns number of bins */
__forceinline size_t size() const { return num; }
/*! slower but safe binning */
__forceinline Vec3ia bin(const Vec3fa& p) const
{
const vint4 i = floori((vfloat4(p)-ofs)*scale);
assert(i[0] >= 0 && (size_t)i[0] < num);
assert(i[1] >= 0 && (size_t)i[1] < num);
assert(i[2] >= 0 && (size_t)i[2] < num);
// we clamp to handle corner cases that could calculate out of bounds bin
return Vec3ia(clamp(i,vint4(0),vint4(num-1)));
}
/*! faster but unsafe binning */
__forceinline Vec3ia bin_unsafe(const Vec3fa& p) const {
return Vec3ia(floori((vfloat4(p)-ofs)*scale));
}
/*! faster but unsafe binning */
template<typename PrimRef>
__forceinline Vec3ia bin_unsafe(const PrimRef& p) const {
return bin_unsafe(p.binCenter());
}
/*! faster but unsafe binning */
template<typename PrimRef, typename BinBoundsAndCenter>
__forceinline Vec3ia bin_unsafe(const PrimRef& p, const BinBoundsAndCenter& binBoundsAndCenter) const {
return bin_unsafe(binBoundsAndCenter.binCenter(p));
}
template<typename PrimRef>
__forceinline bool bin_unsafe(const PrimRef& ref,
const vint4& vSplitPos,
const vbool4& splitDimMask) const // FIXME: rename to isLeft
{
return any(((vint4)bin_unsafe(center2(ref.bounds())) < vSplitPos) & splitDimMask);
}
/*! calculates left spatial position of bin */
__forceinline float pos(const size_t bin, const size_t dim) const {
return madd(float(bin),1.0f / scale[dim],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;
}
/*! stream output */
friend embree_ostream operator<<(embree_ostream cout, const BinMapping& mapping) {
return cout << "BinMapping { num = " << mapping.num << ", ofs = " << mapping.ofs << ", scale = " << mapping.scale << "}";
}
public:
size_t num;
vfloat4 ofs,scale; //!< linear function that maps to bin ID
};
/*! stores all information to perform some split */
template<size_t BINS>
struct BinSplit
{
enum
{
SPLIT_OBJECT = 0,
SPLIT_FALLBACK = 1,
SPLIT_ENFORCE = 2, // splits with larger ID are enforced in createLargeLeaf even if we could create a leaf already
SPLIT_TEMPORAL = 2,
SPLIT_GEOMID = 3,
};
/*! construct an invalid split by default */
__forceinline BinSplit()
: sah(inf), dim(-1), pos(0), data(0) {}
__forceinline BinSplit(float sah, unsigned data, int dim = 0, float fpos = 0)
: sah(sah), dim(dim), fpos(fpos), data(data) {}
/*! constructs specified split */
__forceinline BinSplit(float sah, int dim, int pos, const BinMapping<BINS>& mapping)
: sah(sah), dim(dim), pos(pos), data(0), 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 BinSplit& split) {
return cout << "BinSplit { sah = " << split.sah << ", dim = " << split.dim << ", pos = " << split.pos << "}";
}
public:
float sah; //!< SAH cost of the split
int dim; //!< split dimension
union { int pos; float fpos; }; //!< bin index for splitting
unsigned int data; //!< extra optional split data
BinMapping<BINS> mapping; //!< mapping into bins
};
/*! stores extended information about the split */
template<typename BBox>
struct SplitInfoT
{
__forceinline SplitInfoT () {}
__forceinline SplitInfoT (size_t leftCount, const BBox& leftBounds, size_t rightCount, const BBox& rightBounds)
: leftCount(leftCount), rightCount(rightCount), leftBounds(leftBounds), rightBounds(rightBounds) {}
public:
size_t leftCount,rightCount;
BBox leftBounds,rightBounds;
};
typedef SplitInfoT<BBox3fa> SplitInfo;
typedef SplitInfoT<LBBox3fa> SplitInfo2;
/*! stores all binning information */
template<size_t BINS, typename PrimRef, typename BBox>
struct __aligned(64) BinInfoT
{
typedef BinSplit<BINS> Split;
typedef vbool4 vbool;
typedef vint4 vint;
typedef vfloat4 vfloat;
__forceinline BinInfoT() {
}
__forceinline BinInfoT(EmptyTy) {
clear();
}
/*! bin access function */
__forceinline BBox &bounds(const size_t binID, const size_t dimID) { return _bounds[binID][dimID]; }
__forceinline const BBox &bounds(const size_t binID, const size_t dimID) const { return _bounds[binID][dimID]; }
__forceinline unsigned int &counts(const size_t binID, const size_t dimID) { return _counts[binID][dimID]; }
__forceinline const unsigned int &counts(const size_t binID, const size_t dimID) const { return _counts[binID][dimID]; }
__forceinline vuint4 &counts(const size_t binID) { return _counts[binID]; }
__forceinline const vuint4 &counts(const size_t binID) const { return _counts[binID]; }
/*! 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;
counts(i) = vuint4(zero);
}
}
/*! bins an array of primitives */
__forceinline void bin (const PrimRef* prims, size_t N, const BinMapping<BINS>& mapping)
{
if (unlikely(N == 0)) return;
size_t i;
for (i=0; i<N-1; i+=2)
{
/*! map even and odd primitive to bin */
BBox prim0; Vec3fa center0;
prims[i+0].binBoundsAndCenter(prim0,center0);
const vint4 bin0 = (vint4)mapping.bin(center0);
BBox prim1; Vec3fa center1;
prims[i+1].binBoundsAndCenter(prim1,center1);
const vint4 bin1 = (vint4)mapping.bin(center1);
/*! increase bounds for bins for even primitive */
const unsigned int b00 = extract<0>(bin0); bounds(b00,0).extend(prim0);
const unsigned int b01 = extract<1>(bin0); bounds(b01,1).extend(prim0);
const unsigned int b02 = extract<2>(bin0); bounds(b02,2).extend(prim0);
const unsigned int s0 = (unsigned int)prims[i+0].size();
counts(b00,0)+=s0;
counts(b01,1)+=s0;
counts(b02,2)+=s0;
/*! increase bounds of bins for odd primitive */
const unsigned int b10 = extract<0>(bin1); bounds(b10,0).extend(prim1);
const unsigned int b11 = extract<1>(bin1); bounds(b11,1).extend(prim1);
const unsigned int b12 = extract<2>(bin1); bounds(b12,2).extend(prim1);
const unsigned int s1 = (unsigned int)prims[i+1].size();
counts(b10,0)+=s1;
counts(b11,1)+=s1;
counts(b12,2)+=s1;
}
/*! for uneven number of primitives */
if (i < N)
{
/*! map primitive to bin */
BBox prim0; Vec3fa center0;
prims[i].binBoundsAndCenter(prim0,center0);
const vint4 bin0 = (vint4)mapping.bin(center0);
/*! increase bounds of bins */
const unsigned int s0 = (unsigned int)prims[i].size();
const int b00 = extract<0>(bin0); counts(b00,0)+=s0; bounds(b00,0).extend(prim0);
const int b01 = extract<1>(bin0); counts(b01,1)+=s0; bounds(b01,1).extend(prim0);
const int b02 = extract<2>(bin0); counts(b02,2)+=s0; bounds(b02,2).extend(prim0);
}
}
/*! bins an array of primitives */
template<typename BinBoundsAndCenter>
__forceinline void bin (const PrimRef* prims, size_t N, const BinMapping<BINS>& mapping, const BinBoundsAndCenter& binBoundsAndCenter)
{
if (N == 0) return;
size_t i;
for (i=0; i<N-1; i+=2)
{
/*! map even and odd primitive to bin */
BBox prim0; Vec3fa center0; binBoundsAndCenter.binBoundsAndCenter(prims[i+0],prim0,center0);
const vint4 bin0 = (vint4)mapping.bin(center0);
BBox prim1; Vec3fa center1; binBoundsAndCenter.binBoundsAndCenter(prims[i+1],prim1,center1);
const vint4 bin1 = (vint4)mapping.bin(center1);
/*! increase bounds for bins for even primitive */
const unsigned int s0 = prims[i+0].size();
const int b00 = extract<0>(bin0); counts(b00,0)+=s0; bounds(b00,0).extend(prim0);
const int b01 = extract<1>(bin0); counts(b01,1)+=s0; bounds(b01,1).extend(prim0);
const int b02 = extract<2>(bin0); counts(b02,2)+=s0; bounds(b02,2).extend(prim0);
/*! increase bounds of bins for odd primitive */
const unsigned int s1 = prims[i+1].size();
const int b10 = extract<0>(bin1); counts(b10,0)+=s1; bounds(b10,0).extend(prim1);
const int b11 = extract<1>(bin1); counts(b11,1)+=s1; bounds(b11,1).extend(prim1);
const int b12 = extract<2>(bin1); counts(b12,2)+=s1; bounds(b12,2).extend(prim1);
}
/*! for uneven number of primitives */
if (i < N)
{
/*! map primitive to bin */
BBox prim0; Vec3fa center0; binBoundsAndCenter.binBoundsAndCenter(prims[i+0],prim0,center0);
const vint4 bin0 = (vint4)mapping.bin(center0);
/*! increase bounds of bins */
const unsigned int s0 = prims[i+0].size();
const int b00 = extract<0>(bin0); counts(b00,0)+=s0; bounds(b00,0).extend(prim0);
const int b01 = extract<1>(bin0); counts(b01,1)+=s0; bounds(b01,1).extend(prim0);
const int b02 = extract<2>(bin0); counts(b02,2)+=s0; bounds(b02,2).extend(prim0);
}
}
__forceinline void bin(const PrimRef* prims, size_t begin, size_t end, const BinMapping<BINS>& mapping) {
bin(prims+begin,end-begin,mapping);
}
template<typename BinBoundsAndCenter>
__forceinline void bin(const PrimRef* prims, size_t begin, size_t end, const BinMapping<BINS>& mapping, const BinBoundsAndCenter& binBoundsAndCenter) {
bin<BinBoundsAndCenter>(prims+begin,end-begin,mapping,binBoundsAndCenter);
}
/*! merges in other binning information */
__forceinline void merge (const BinInfoT& other, size_t numBins)
{
for (size_t i=0; i<numBins; i++)
{
counts(i) += other.counts(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));
}
}
/*! reduces binning information */
static __forceinline const BinInfoT reduce (const BinInfoT& a, const BinInfoT& b, const size_t numBins = BINS)
{
BinInfoT c;
for (size_t i=0; i<numBins; i++)
{
c.counts(i) = a.counts(i)+b.counts(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 */
__forceinline Split best(const BinMapping<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; BBox bx = empty; BBox by = empty; BBox bz = empty;
for (size_t i=mapping.size()-1; i>0; i--)
{
count += counts(i);
rCounts[i] = count;
bx.extend(bounds(i,0)); rAreas[i][0] = expectedApproxHalfArea(bx);
by.extend(bounds(i,1)); rAreas[i][1] = expectedApproxHalfArea(by);
bz.extend(bounds(i,2)); rAreas[i][2] = expectedApproxHalfArea(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;
count = 0; bx = empty; by = empty; bz = empty;
for (size_t i=1; i<mapping.size(); i++, ii+=1)
{
count += counts(i-1);
bx.extend(bounds(i-1,0)); float Ax = expectedApproxHalfArea(bx);
by.extend(bounds(i-1,1)); float Ay = expectedApproxHalfArea(by);
bz.extend(bounds(i-1,2)); float Az = expectedApproxHalfArea(bz);
const vfloat4 lArea = vfloat4(Ax,Ay,Az,Az);
const vfloat4 rArea = rAreas[i];
const vuint4 lCount = (count +blocks_add) >> (unsigned int)(blocks_shift); // if blocks_shift >=1 then lCount < 4B and could be represented with an vint4, which would allow for faster vfloat4 conversions.
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)));
vbestPos = select(sah < vbestSAH,ii ,vbestPos);
vbestSAH = select(sah < vbestSAH,sah,vbestSAH);
}
/* find best dimension */
float bestSAH = inf;
int bestDim = -1;
int bestPos = 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];
}
}
return Split(bestSAH,bestDim,bestPos,mapping);
}
/*! finds the best split by scanning binning information */
__forceinline Split best_block_size(const BinMapping<BINS>& mapping, const size_t blockSize) const
{
/* sweep from right to left and compute parallel prefix of merged bounds */
vfloat4 rAreas[BINS];
vuint4 rCounts[BINS];
vuint4 count = 0; BBox bx = empty; BBox by = empty; BBox bz = empty;
for (size_t i=mapping.size()-1; i>0; i--)
{
count += counts(i);
rCounts[i] = count;
bx.extend(bounds(i,0)); rAreas[i][0] = expectedApproxHalfArea(bx);
by.extend(bounds(i,1)); rAreas[i][1] = expectedApproxHalfArea(by);
bz.extend(bounds(i,2)); rAreas[i][2] = expectedApproxHalfArea(bz);
rAreas[i][3] = 0.0f;
}
/* sweep from left to right and compute SAH */
vuint4 blocks_add = blockSize-1;
vfloat4 blocks_factor = 1.0f/float(blockSize);
vuint4 ii = 1; vfloat4 vbestSAH = pos_inf; vuint4 vbestPos = 0;
count = 0; bx = empty; by = empty; bz = empty;
for (size_t i=1; i<mapping.size(); i++, ii+=1)
{
count += counts(i-1);
bx.extend(bounds(i-1,0)); float Ax = expectedApproxHalfArea(bx);
by.extend(bounds(i-1,1)); float Ay = expectedApproxHalfArea(by);
bz.extend(bounds(i-1,2)); float Az = expectedApproxHalfArea(bz);
const vfloat4 lArea = vfloat4(Ax,Ay,Az,Az);
const vfloat4 rArea = rAreas[i];
const vfloat4 lCount = floor(vfloat4(count +blocks_add)*blocks_factor);
const vfloat4 rCount = floor(vfloat4(rCounts[i]+blocks_add)*blocks_factor);
const vfloat4 sah = madd(lArea,lCount,rArea*rCount);
vbestPos = select(sah < vbestSAH,ii ,vbestPos);
vbestSAH = select(sah < vbestSAH,sah,vbestSAH);
}
/* find best dimension */
float bestSAH = inf;
int bestDim = -1;
int bestPos = 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];
}
}
return Split(bestSAH,bestDim,bestPos,mapping);
}
/*! calculates extended split information */
__forceinline void getSplitInfo(const BinMapping<BINS>& mapping, const Split& split, SplitInfoT<BBox>& info) const
{
if (split.dim == -1) {
new (&info) SplitInfoT<BBox>(0,empty,0,empty);
return;
}
size_t leftCount = 0;
BBox leftBounds = empty;
for (size_t i=0; i<(size_t)split.pos; i++) {
leftCount += counts(i,split.dim);
leftBounds.extend(bounds(i,split.dim));
}
size_t rightCount = 0;
BBox rightBounds = empty;
for (size_t i=split.pos; i<mapping.size(); i++) {
rightCount += counts(i,split.dim);
rightBounds.extend(bounds(i,split.dim));
}
new (&info) SplitInfoT<BBox>(leftCount,leftBounds,rightCount,rightBounds);
}
/*! gets the number of primitives left of the split */
__forceinline size_t getLeftCount(const BinMapping<BINS>& mapping, const Split& split) const
{
if (unlikely(split.dim == -1)) return -1;
size_t leftCount = 0;
for (size_t i = 0; i < (size_t)split.pos; i++) {
leftCount += counts(i, split.dim);
}
return leftCount;
}
/*! gets the number of primitives right of the split */
__forceinline size_t getRightCount(const BinMapping<BINS>& mapping, const Split& split) const
{
if (unlikely(split.dim == -1)) return -1;
size_t rightCount = 0;
for (size_t i = (size_t)split.pos; i<mapping.size(); i++) {
rightCount += counts(i, split.dim);
}
return rightCount;
}
private:
BBox _bounds[BINS][3]; //!< geometry bounds for each bin in each dimension
vuint4 _counts[BINS]; //!< counts number of primitives that map into the bins
};
}
template<typename BinInfoT, typename BinMapping, typename PrimRef>
__forceinline void bin_parallel(BinInfoT& binner, const PrimRef* prims, size_t begin, size_t end, size_t blockSize, size_t parallelThreshold, const BinMapping& mapping)
{
if (likely(end-begin < parallelThreshold)) {
binner.bin(prims,begin,end,mapping);
} else {
binner = parallel_reduce(begin,end,blockSize,binner,
[&](const range<size_t>& r) -> BinInfoT { BinInfoT binner(empty); binner.bin(prims + r.begin(), r.size(), mapping); return binner; },
[&](const BinInfoT& b0, const BinInfoT& b1) -> BinInfoT { BinInfoT r = b0; r.merge(b1, mapping.size()); return r; });
}
}
template<typename BinBoundsAndCenter, typename BinInfoT, typename BinMapping, typename PrimRef>
__forceinline void bin_parallel(BinInfoT& binner, const PrimRef* prims, size_t begin, size_t end, size_t blockSize, size_t parallelThreshold, const BinMapping& mapping, const BinBoundsAndCenter& binBoundsAndCenter)
{
if (likely(end-begin < parallelThreshold)) {
binner.bin(prims,begin,end,mapping,binBoundsAndCenter);
} else {
binner = parallel_reduce(begin,end,blockSize,binner,
[&](const range<size_t>& r) -> BinInfoT { BinInfoT binner(empty); binner.bin(prims + r.begin(), r.size(), mapping, binBoundsAndCenter); return binner; },
[&](const BinInfoT& b0, const BinInfoT& b1) -> BinInfoT { BinInfoT r = b0; r.merge(b1, mapping.size()); return r; });
}
}
template<bool parallel, typename BinInfoT, typename BinMapping, typename PrimRef>
__forceinline void bin_serial_or_parallel(BinInfoT& binner, const PrimRef* prims, size_t begin, size_t end, size_t blockSize, const BinMapping& mapping)
{
if (!parallel) {
binner.bin(prims,begin,end,mapping);
} else {
binner = parallel_reduce(begin,end,blockSize,binner,
[&](const range<size_t>& r) -> BinInfoT { BinInfoT binner(empty); binner.bin(prims + r.begin(), r.size(), mapping); return binner; },
[&](const BinInfoT& b0, const BinInfoT& b1) -> BinInfoT { BinInfoT r = b0; r.merge(b1, mapping.size()); return r; });
}
}
template<bool parallel, typename BinBoundsAndCenter, typename BinInfoT, typename BinMapping, typename PrimRef>
__forceinline void bin_serial_or_parallel(BinInfoT& binner, const PrimRef* prims, size_t begin, size_t end, size_t blockSize, const BinMapping& mapping, const BinBoundsAndCenter& binBoundsAndCenter)
{
if (!parallel) {
binner.bin(prims,begin,end,mapping,binBoundsAndCenter);
} else {
binner = parallel_reduce(begin,end,blockSize,binner,
[&](const range<size_t>& r) -> BinInfoT { BinInfoT binner(empty); binner.bin(prims + r.begin(), r.size(), mapping, binBoundsAndCenter); return binner; },
[&](const BinInfoT& b0, const BinInfoT& b1) -> BinInfoT { BinInfoT r = b0; r.merge(b1, mapping.size()); return r; });
}
}
}