Open3D (C++ API)  0.19.0
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ParallelScan.h
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1// ----------------------------------------------------------------------------
2// - Open3D: www.open3d.org -
3// ----------------------------------------------------------------------------
4// Copyright (c) 2018-2024 www.open3d.org
5// SPDX-License-Identifier: MIT
6// ----------------------------------------------------------------------------
7
8#pragma once
9
10#include <tbb/parallel_for.h>
11#include <tbb/parallel_scan.h>
12
13namespace open3d {
14namespace utility {
15
16namespace {
17template <class Tin, class Tout>
18class ScanSumBody {
19 Tout sum;
20 const Tin* in;
21 Tout* const out;
22
23public:
24 ScanSumBody(Tout* out_, const Tin* in_) : sum(0), in(in_), out(out_) {}
25 Tout get_sum() const { return sum; }
26
27 template <class Tag>
28 void operator()(const tbb::blocked_range<size_t>& r, Tag) {
29 Tout temp = sum;
30 for (size_t i = r.begin(); i < r.end(); ++i) {
31 temp = temp + in[i];
32 if (Tag::is_final_scan()) out[i] = temp;
33 }
34 sum = temp;
35 }
36 ScanSumBody(ScanSumBody& b, tbb::split) : sum(0), in(b.in), out(b.out) {}
37 void reverse_join(ScanSumBody& a) { sum = a.sum + sum; }
38 void assign(ScanSumBody& b) { sum = b.sum; }
39};
40} // namespace
41
42template <class Tin, class Tout>
43void InclusivePrefixSum(const Tin* first, const Tin* last, Tout* out) {
44 ScanSumBody<Tin, Tout> body(out, first);
45 size_t n = std::distance(first, last);
46 tbb::parallel_scan(tbb::blocked_range<size_t>(0, n), body);
47}
48
49} // namespace utility
50} // namespace open3d
void InclusivePrefixSum(const Tin *first, const Tin *last, Tout *out)
Definition ParallelScan.h:43
Definition PinholeCameraIntrinsic.cpp:16