ode/src/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 #include "config.h"
  44
  45
  46 // this base class has no constructors or destructor, for your convenience.
  47
  48 class dArrayBase {
  49 protected:
  50   int _size;            // number of elements in `data'
  51   int _anum;            // allocated number of elements in `data'
  52   void *_data;          // array data
  53
  54   void _freeAll (int sizeofT);
  55   void _setSize (int newsize, int sizeofT);
  56   // set the array size to `newsize', allocating more memory if necessary.
  57   // if newsize>_anum and is a power of two then this is guaranteed to
  58   // set _size and _anum to newsize.
  59
  60 public:
  61   // not: dArrayBase () { _size=0; _anum=0; _data=0; }
  62
  63   int size() const { return _size; }
  64   int allocatedSize() const { return _anum; }
  65   void * operator new (size_t size);
  66   void operator delete (void *ptr, size_t size);
  67
  68   void constructor() { _size=0; _anum=0; _data=0; }
  69   // if this structure is allocated with malloc() instead of new, you can
  70   // call this to set it up.
  71
  72   void constructLocalArray (int __anum);
  73   // this helper function allows non-reallocating arrays to be constructed
  74   // on the stack (or in the heap if necessary). this is something of a
  75   // kludge and should be used with extreme care. this function acts like
  76   // a constructor - it is called on uninitialized memory that will hold the
  77   // Array structure and the data. __anum is the number of elements that
  78   // are allocated. the memory MUST be allocated with size:
  79   //   sizeof(ArrayBase) + __anum*sizeof(T)
  80   // arrays allocated this way will never try to reallocate or free the
  81   // memory - that's your job.
  82 };
  83
  84
  85 template <class T> class dArray : public dArrayBase {
  86 public:
  87   void equals (const dArray<T> &x) {
  88     setSize (x.size());
  89     memcpy (_data,x._data,x._size * sizeof(T));
  90   }
  91
  92   dArray () { constructor(); }
  93   dArray (const dArray<T> &x) { constructor(); equals (x); }
  94   ~dArray () { _freeAll(sizeof(T)); }
  95   void setSize (int newsize) { _setSize (newsize,sizeof(T)); }
  96   T *data() const { return (T*) _data; }
  97   T & operator[] (int i) const { return ((T*)_data)[i]; }
  98   void operator = (const dArray<T> &x) { equals (x); }
  99
 100   void push (const T item) {
 101     if (_size < _anum) _size++; else _setSize (_size+1,sizeof(T));
 102     memcpy (&(((T*)_data)[_size-1]), &item, sizeof(T));
 103   }
 104
 105   void swap (dArray<T> &x) {
 106     int tmp1;
 107     void *tmp2;
 108     tmp1=_size; _size=x._size; x._size=tmp1;
 109     tmp1=_anum; _anum=x._anum; x._anum=tmp1;
 110     tmp2=_data; _data=x._data; x._data=tmp2;
 111   }
 112
 113   // insert the item at the position `i'. if i<0 then add the item to the
 114   // start, if i >= size then add the item to the end of the array.
 115   void insert (int i, const T item) {
 116     if (_size < _anum) _size++; else _setSize (_size+1,sizeof(T));
 117     if (i >= (_size-1)) i = _size-1;    // add to end
 118     else {
 119       if (i < 0) i=0;                   // add to start
 120       int n = _size-1-i;
 121       if (n>0) memmove (((T*)_data) + i+1, ((T*)_data) + i, n*sizeof(T));
 122     }
 123     ((T*)_data)[i] = item;
 124   }
 125
 126   void remove (int i) {
 127     if (i >= 0 && i < _size) {  // passing this test guarantees size>0
 128       int n = _size-1-i;
 129       if (n>0) memmove (((T*)_data) + i, ((T*)_data) + i+1, n*sizeof(T));
 130       _size--;
 131     }
 132   }
 133 };
 134
 135
 136 #endif