1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
|
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of NVIDIA CORPORATION nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Copyright (c) 2018 NVIDIA Corporation. All rights reserved.
#ifndef APEX_MERGE_H
#define APEX_MERGE_H
namespace nvidia
{
namespace apex
{
// merge 2 increasingly sorted arrays
// it's ok if one of the input buffers is also the results array
template<class Sortable>
bool ApexMerge(Sortable* bufferA, uint32_t numEntriesA, Sortable* bufferB, uint32_t numEntriesB, Sortable* resultBuffer, uint32_t numEntriesResult, int (*compare)(const void*, const void*))
{
if (numEntriesResult != numEntriesA + numEntriesB)
return false;
#if PX_CHECKED
if (numEntriesA > 0)
{
for (uint32_t i = 1; i < numEntriesA; ++i)
{
PX_ASSERT(compare(bufferA + i - 1, bufferA + i) <= 0);
}
}
if (numEntriesB > 0)
{
for (uint32_t i = 1; i < numEntriesB; ++i)
{
PX_ASSERT(compare(bufferB + i - 1, bufferB + i) <= 0);
}
}
#endif
int32_t iA = (int32_t)numEntriesA-1;
int32_t iB = (int32_t)numEntriesB-1;
uint32_t iResult = numEntriesA + numEntriesB - 1;
while (iA >= 0 && iB >= 0)
{
if (compare(&bufferA[iA], &bufferB[iB]) > 0)
{
resultBuffer[iResult] = bufferA[iA--];
}
else
{
resultBuffer[iResult] = bufferB[iB--];
}
--iResult;
}
if (iA < 0)
{
if (resultBuffer != bufferB)
{
memcpy(resultBuffer, bufferB, (iB + 1) * sizeof(Sortable));
}
}
else
{
if (resultBuffer != bufferA)
{
memcpy(resultBuffer, bufferA, (iA + 1) * sizeof(Sortable));
}
}
return true;
}
} // namespace apex
} // namespace nvidia
#endif // APEX_MERGE_H
|