Box2D  2.4.1
A 2D physics engine for games
b2_growable_stack.h
1 // MIT License
2 
3 // Copyright (c) 2019 Erin Catto
4 
5 // Permission is hereby granted, free of charge, to any person obtaining a copy
6 // of this software and associated documentation files (the "Software"), to deal
7 // in the Software without restriction, including without limitation the rights
8 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 // copies of the Software, and to permit persons to whom the Software is
10 // furnished to do so, subject to the following conditions:
11 
12 // The above copyright notice and this permission notice shall be included in all
13 // copies or substantial portions of the Software.
14 
15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 // SOFTWARE.
22 
23 #ifndef B2_GROWABLE_STACK_H
24 #define B2_GROWABLE_STACK_H
25 
26 #include <string.h>
27 
28 #include "b2_settings.h"
29 
33 template <typename T, int32 N>
35 {
36 public:
38  {
39  m_stack = m_array;
40  m_count = 0;
41  m_capacity = N;
42  }
43 
45  {
46  if (m_stack != m_array)
47  {
48  b2Free(m_stack);
49  m_stack = nullptr;
50  }
51  }
52 
53  void Push(const T& element)
54  {
55  if (m_count == m_capacity)
56  {
57  T* old = m_stack;
58  m_capacity *= 2;
59  m_stack = (T*)b2Alloc(m_capacity * sizeof(T));
60  memcpy(m_stack, old, m_count * sizeof(T));
61  if (old != m_array)
62  {
63  b2Free(old);
64  }
65  }
66 
67  m_stack[m_count] = element;
68  ++m_count;
69  }
70 
71  T Pop()
72  {
73  b2Assert(m_count > 0);
74  --m_count;
75  return m_stack[m_count];
76  }
77 
78  int32 GetCount()
79  {
80  return m_count;
81  }
82 
83 private:
84  T* m_stack;
85  T m_array[N];
86  int32 m_count;
87  int32 m_capacity;
88 };
89 
90 
91 #endif
b2_settings.h
b2Alloc
void * b2Alloc(int32 size)
Implement this function to use your own memory allocator.
Definition: b2_settings.h:100
b2GrowableStack
Definition: b2_growable_stack.h:34
b2Free
void b2Free(void *mem)
If you implement b2Alloc, you should also implement this function.
Definition: b2_settings.h:106