VTK  9.1.0
vtkStateStorage.h
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1/*=========================================================================
2
3 Program: Visualization Toolkit
4
5 Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
6 All rights reserved.
7 See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
8
9 This software is distributed WITHOUT ANY WARRANTY; without even
10 the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
11 PURPOSE. See the above copyright notice for more information.
12
13=========================================================================*/
47#ifndef vtkStateStorage_h
48#define vtkStateStorage_h
49
50#include <algorithm>
51#include <string>
52#include <vector>
53
54// uncomment the following line to add in state debugging information
55//#define USE_STATE_DEBUGGING 1
56#ifdef USE_STATE_DEBUGGING
57
59{
60public:
62
63 // clear the storage
64 void Clear()
65 {
66 this->Storage.clear();
67 this->StorageOffsets.clear();
68 this->StorageNames.clear();
69 }
70
71 // append a data item to the state
72 template <class T>
73 void Append(const T& value, const char* name);
74
75 bool operator!=(const vtkStateStorage& b) const
76 {
77 // for debug we also lookup the name of what was different
78 this->WhatWasDifferent = "";
79 if (this->Storage.size() != b.Storage.size())
80 {
81 this->WhatWasDifferent = "Different state sizes";
82 return true;
83 }
84 for (size_t i = 0; i < this->Storage.size(); ++i)
85 {
86 if (this->Storage[i] != b.Storage[i])
87 {
88 size_t block = 0;
89 while (this->StorageOffsets.size() > block + 1 && this->StorageOffsets[block + 1] >= i)
90 {
91 block++;
92 }
93 this->WhatWasDifferent = this->StorageNames[block] + " was different";
94 return true;
95 }
96 }
97 return false;
98 }
99
101 {
102 this->Storage = b.Storage;
103 this->StorageNames = b.StorageNames;
104 this->StorageOffsets = b.StorageOffsets;
105 return *this;
106 }
107
108protected:
109 std::vector<unsigned char> Storage;
110 std::vector<std::string> StorageNames;
111 std::vector<size_t> StorageOffsets;
112 mutable std::string WhatWasDifferent;
113
114private:
115 vtkStateStorage(const vtkStateStorage&) = delete;
116};
117
118template <class T>
119inline void vtkStateStorage::Append(const T& value, const char* name)
120{
121 this->StorageOffsets.push_back(this->Storage.size());
122 this->StorageNames.push_back(name);
123 const char* start = reinterpret_cast<const char*>(&value);
124 this->Storage.insert(this->Storage.end(), start, start + sizeof(T));
125}
126
127#else // normal implementation
128
130{
131public:
132 vtkStateStorage() = default;
133
134 // clear the storage
135 void Clear() { this->Storage.clear(); }
136
137 // append a data item to the state
138 template <class T>
139 void Append(const T& value, const char* name);
140
141 bool operator!=(const vtkStateStorage& b) const { return this->Storage != b.Storage; }
142
144
145protected:
146 std::vector<unsigned char> Storage;
147
148private:
149 vtkStateStorage(const vtkStateStorage&) = delete;
150};
151
152template <class T>
153inline void vtkStateStorage::Append(const T& value, const char*)
154{
155 const char* start = reinterpret_cast<const char*>(&value);
156 this->Storage.insert(this->Storage.end(), start, start + sizeof(T));
157}
158
159#endif // normal implementation
160
161#endif // vtkStateStorage_h
162
163// VTK-HeaderTest-Exclude: vtkStateStorage.h
Class to make storing and comparing state quick and easy.
std::vector< unsigned char > Storage
void Append(const T &value, const char *name)
vtkStateStorage()=default
bool operator!=(const vtkStateStorage &b) const
vtkStateStorage & operator=(const vtkStateStorage &b)=default
@ value
Definition: vtkX3D.h:226