/*************************************************************************

 *                                                                       *

 * Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith.       *

 * All rights reserved.  Email: russ@q12.org   Web: www.q12.org          *

 *                                                                       *

 * This library is free software; you can redistribute it and/or         *

 * modify it under the terms of EITHER:                                  *

 *   (1) The GNU Lesser General Public License as published by the Free  *

 *       Software Foundation; either version 2.1 of the License, or (at  *

 *       your option) any later version. The text of the GNU Lesser      *

 *       General Public License is included with this library in the     *

 *       file LICENSE.TXT.                                               *

 *   (2) The BSD-style license that is included with this library in     *

 *       the file LICENSE-BSD.TXT.                                       *

 *                                                                       *

 * This library is distributed in the hope that it will be useful,       *

 * but WITHOUT ANY WARRANTY; without even the implied warranty of        *

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files    *

 * LICENSE.TXT and LICENSE-BSD.TXT for more details.                     *

 *                                                                       *

 *************************************************************************/

/* this comes from the `reuse' library. copy any changes back to the source.

 *

 * Variable sized array template. The array is always stored in a contiguous

 * chunk. The array can be resized. A size increase will cause more memory

 * to be allocated, and may result in relocation of the array memory.

 * A size decrease has no effect on the memory allocation.

 *

 * Array elements with constructors or destructors are not supported!

 * But if you must have such elements, here's what to know/do:

 *   - Bitwise copy is used when copying whole arrays.

 *   - When copying individual items (via push(), insert() etc) the `='

 *     (equals) operator is used. Thus you should define this operator to do

 *     a bitwise copy. You should probably also define the copy constructor.

 */

#ifndef _ODE_ARRAY_H_

#define _ODE_ARRAY_H_

#include <ode/config.h>

// this base class has no constructors or destructor, for your convenience.

class dArrayBase {

protected:

  int _size;		// number of elements in `data'

  int _anum;		// allocated number of elements in `data'

  void *_data;		// array data

  void _freeAll (int sizeofT);

  void _setSize (int newsize, int sizeofT);

  // set the array size to `newsize', allocating more memory if necessary.

  // if newsize>_anum and is a power of two then this is guaranteed to

  // set _size and _anum to newsize.

public:

  // not: dArrayBase () { _size=0; _anum=0; _data=0; }

  int size() const { return _size; }

  int allocatedSize() const { return _anum; }

  void * operator new (size_t size);

  void operator delete (void *ptr, size_t size);

  void constructor() { _size=0; _anum=0; _data=0; }

  // if this structure is allocated with malloc() instead of new, you can

  // call this to set it up.

  void constructLocalArray (int __anum);

  // this helper function allows non-reallocating arrays to be constructed

  // on the stack (or in the heap if necessary). this is something of a

  // kludge and should be used with extreme care. this function acts like

  // a constructor - it is called on uninitialized memory that will hold the

  // Array structure and the data. __anum is the number of elements that

  // are allocated. the memory MUST be allocated with size:

  //   sizeof(ArrayBase) + __anum*sizeof(T)

  // arrays allocated this way will never try to reallocate or free the

  // memory - that's your job.

};

template <class T> class dArray : public dArrayBase {

public:

  void equals (const dArray<T> &x) {

    setSize (x.size());

    memcpy (_data,x._data,x._size * sizeof(T));

  }

  dArray () { constructor(); }

  dArray (const dArray<T> &x) { constructor(); equals (x); }

  ~dArray () { _freeAll(sizeof(T)); }

  void setSize (int newsize) { _setSize (newsize,sizeof(T)); }

  T *data() const { return (T*) _data; }

  T & operator[] (int i) const { return ((T*)_data)[i]; }

  void operator = (const dArray<T> &x) { equals (x); }

  void push (const T item) {

    if (_size < _anum) _size++; else _setSize (_size+1,sizeof(T));

    memcpy (&(((T*)_data)[_size-1]), &item, sizeof(T));

  }

  void swap (dArray<T> &x) {

    int tmp1;

    void *tmp2;

    tmp1=_size; _size=x._size; x._size=tmp1;

    tmp1=_anum; _anum=x._anum; x._anum=tmp1;

    tmp2=_data; _data=x._data; x._data=tmp2;

  }

  // insert the item at the position `i'. if i<0 then add the item to the

  // start, if i >= size then add the item to the end of the array.

  void insert (int i, const T item) {

    if (_size < _anum) _size++; else _setSize (_size+1,sizeof(T));

    if (i >= (_size-1)) i = _size-1;	// add to end

    else {

      if (i < 0) i=0;			// add to start

      int n = _size-1-i;

      if (n>0) memmove (((T*)_data) + i+1, ((T*)_data) + i, n*sizeof(T));

    }

    ((T*)_data)[i] = item;

  }

  void remove (int i) {

    if (i >= 0 && i < _size) {	// passing this test guarantees size>0

      int n = _size-1-i;

      if (n>0) memmove (((T*)_data) + i, ((T*)_data) + i+1, n*sizeof(T));

      _size--;

    }

  }

};

#endif