Open Dynamics Engine
array.h
1 /*************************************************************************
2  * *
3  * Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith. *
4  * All rights reserved. Email: russ@q12.org Web: www.q12.org *
5  * *
6  * This library is free software; you can redistribute it and/or *
7  * modify it under the terms of EITHER: *
8  * (1) The GNU Lesser General Public License as published by the Free *
9  * Software Foundation; either version 2.1 of the License, or (at *
10  * your option) any later version. The text of the GNU Lesser *
11  * General Public License is included with this library in the *
12  * file LICENSE.TXT. *
13  * (2) The BSD-style license that is included with this library in *
14  * the file LICENSE-BSD.TXT. *
15  * *
16  * This library is distributed in the hope that it will be useful, *
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of *
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files *
19  * LICENSE.TXT and LICENSE-BSD.TXT for more details. *
20  * *
21  *************************************************************************/
22 
23 /* this comes from the `reuse' library. copy any changes back to the source.
24  *
25  * Variable sized array template. The array is always stored in a contiguous
26  * chunk. The array can be resized. A size increase will cause more memory
27  * to be allocated, and may result in relocation of the array memory.
28  * A size decrease has no effect on the memory allocation.
29  *
30  * Array elements with constructors or destructors are not supported!
31  * But if you must have such elements, here's what to know/do:
32  * - Bitwise copy is used when copying whole arrays.
33  * - When copying individual items (via push(), insert() etc) the `='
34  * (equals) operator is used. Thus you should define this operator to do
35  * a bitwise copy. You should probably also define the copy constructor.
36  */
37 
38 
39 #ifndef _ODE_ARRAY_H_
40 #define _ODE_ARRAY_H_
41 
42 #include <ode/odeconfig.h>
43 
44 
45 // this base class has no constructors or destructor, for your convenience.
46 
47 class dArrayBase {
48 protected:
49  int _size; // number of elements in `data'
50  int _anum; // allocated number of elements in `data'
51  void *_data; // array data
52 
53  void _freeAll (int sizeofT);
54  void _setSize (int newsize, int sizeofT);
55  // set the array size to `newsize', allocating more memory if necessary.
56  // if newsize>_anum and is a power of two then this is guaranteed to
57  // set _size and _anum to newsize.
58 
59 public:
60  // not: dArrayBase () { _size=0; _anum=0; _data=0; }
61 
62  int size() const { return _size; }
63  int allocatedSize() const { return _anum; }
64  void * operator new (size_t size);
65  void operator delete (void *ptr, size_t size);
66 
67  void constructor() { _size=0; _anum=0; _data=0; }
68  // if this structure is allocated with malloc() instead of new, you can
69  // call this to set it up.
70 
71  void constructLocalArray (int __anum);
72  // this helper function allows non-reallocating arrays to be constructed
73  // on the stack (or in the heap if necessary). this is something of a
74  // kludge and should be used with extreme care. this function acts like
75  // a constructor - it is called on uninitialized memory that will hold the
76  // Array structure and the data. __anum is the number of elements that
77  // are allocated. the memory MUST be allocated with size:
78  // sizeof(ArrayBase) + __anum*sizeof(T)
79  // arrays allocated this way will never try to reallocate or free the
80  // memory - that's your job.
81 };
82 
83 
84 template <class T> class dArray : public dArrayBase {
85 public:
86  void equals (const dArray<T> &x) {
87  setSize (x.size());
88  memcpy (_data,x._data,x._size * sizeof(T));
89  }
90 
91  dArray () { constructor(); }
92  dArray (const dArray<T> &x) { constructor(); equals (x); }
93  ~dArray () { _freeAll(sizeof(T)); }
94  void setSize (int newsize) { _setSize (newsize,sizeof(T)); }
95  T *data() const { return (T*) _data; }
96  T & operator[] (int i) const { return ((T*)_data)[i]; }
97  void operator = (const dArray<T> &x) { equals (x); }
98 
99  void push (const T item) {
100  if (_size < _anum) _size++; else _setSize (_size+1,sizeof(T));
101  memcpy (&(((T*)_data)[_size-1]), &item, sizeof(T));
102  }
103 
104  void swap (dArray<T> &x) {
105  int tmp1;
106  void *tmp2;
107  tmp1=_size; _size=x._size; x._size=tmp1;
108  tmp1=_anum; _anum=x._anum; x._anum=tmp1;
109  tmp2=_data; _data=x._data; x._data=tmp2;
110  }
111 
112  // insert the item at the position `i'. if i<0 then add the item to the
113  // start, if i >= size then add the item to the end of the array.
114  void insert (int i, const T item) {
115  if (_size < _anum) _size++; else _setSize (_size+1,sizeof(T));
116  if (i >= (_size-1)) i = _size-1; // add to end
117  else {
118  if (i < 0) i=0; // add to start
119  int n = _size-1-i;
120  if (n>0) memmove (((T*)_data) + i+1, ((T*)_data) + i, n*sizeof(T));
121  }
122  ((T*)_data)[i] = item;
123  }
124 
125  void remove (int i) {
126  if (i >= 0 && i < _size) { // passing this test guarantees size>0
127  int n = _size-1-i;
128  if (n>0) memmove (((T*)_data) + i, ((T*)_data) + i+1, n*sizeof(T));
129  _size--;
130  }
131  }
132 };
133 
134 
135 #endif
Definition: array.h:84
Definition: array.h:47