assimp/contrib/irrXML/irrArray.h

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// Copyright (C) 2002-2005 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine" and the "irrXML" project.
// For conditions of distribution and use, see copyright notice in irrlicht.h and irrXML.h
#ifndef __IRR_ARRAY_H_INCLUDED__
#define __IRR_ARRAY_H_INCLUDED__
#include "irrTypes.h"
#include "heapsort.h"
namespace irr
{
namespace core
{
//! Self reallocating template array (like stl vector) with additional features.
/** Some features are: Heap sorting, binary search methods, easier debugging.
*/
template <class T>
class array
{
public:
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array()
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: data(0), allocated(0), used(0),
free_when_destroyed(true), is_sorted(true)
{
}
//! Constructs a array and allocates an initial chunk of memory.
//! \param start_count: Amount of elements to allocate.
array(u32 start_count)
: data(0), allocated(0), used(0),
free_when_destroyed(true), is_sorted(true)
{
reallocate(start_count);
}
//! Copy constructor
array(const array<T>& other)
: data(0)
{
*this = other;
}
//! Destructor. Frees allocated memory, if set_free_when_destroyed
//! was not set to false by the user before.
~array()
{
if (free_when_destroyed)
delete [] data;
}
//! Reallocates the array, make it bigger or smaller.
//! \param new_size: New size of array.
void reallocate(u32 new_size)
{
T* old_data = data;
data = new T[new_size];
allocated = new_size;
s32 end = used < new_size ? used : new_size;
for (s32 i=0; i<end; ++i)
data[i] = old_data[i];
if (allocated < used)
used = allocated;
delete [] old_data;
}
//! Adds an element at back of array. If the array is to small to
//! add this new element, the array is made bigger.
//! \param element: Element to add at the back of the array.
void push_back(const T& element)
{
if (used + 1 > allocated)
{
// reallocate(used * 2 +1);
// this doesn't work if the element is in the same array. So
// we'll copy the element first to be sure we'll get no data
// corruption
T e;
e = element; // copy element
reallocate(used * 2 +1); // increase data block
data[used++] = e; // push_back
is_sorted = false;
return;
}
data[used++] = element;
is_sorted = false;
}
//! Adds an element at the front of the array. If the array is to small to
//! add this new element, the array is made bigger. Please note that this
//! is slow, because the whole array needs to be copied for this.
//! \param element: Element to add at the back of the array.
void push_front(const T& element)
{
if (used + 1 > allocated)
reallocate(used * 2 +1);
for (int i=(int)used; i>0; --i)
data[i] = data[i-1];
data[0] = element;
is_sorted = false;
++used;
}
//! Insert item into array at specified position. Please use this
//! only if you know what you are doing (possible performance loss).
//! The preferred method of adding elements should be push_back().
//! \param element: Element to be inserted
//! \param index: Where position to insert the new element.
void insert(const T& element, u32 index=0)
{
_IRR_DEBUG_BREAK_IF(index>used) // access violation
if (used + 1 > allocated)
reallocate(used * 2 +1);
for (u32 i=used++; i>index; i--)
data[i] = data[i-1];
data[index] = element;
is_sorted = false;
}
//! Clears the array and deletes all allocated memory.
void clear()
{
delete [] data;
data = 0;
used = 0;
allocated = 0;
is_sorted = true;
}
//! Sets pointer to new array, using this as new workspace.
//! \param newPointer: Pointer to new array of elements.
//! \param size: Size of the new array.
void set_pointer(T* newPointer, u32 size)
{
delete [] data;
data = newPointer;
allocated = size;
used = size;
is_sorted = false;
}
//! Sets if the array should delete the memory it used.
//! \param f: If true, the array frees the allocated memory in its
//! destructor, otherwise not. The default is true.
void set_free_when_destroyed(bool f)
{
free_when_destroyed = f;
}
//! Sets the size of the array.
//! \param usedNow: Amount of elements now used.
void set_used(u32 usedNow)
{
if (allocated < usedNow)
reallocate(usedNow);
used = usedNow;
}
//! Assignement operator
void operator=(const array<T>& other)
{
if (data)
delete [] data;
//if (allocated < other.allocated)
if (other.allocated == 0)
data = 0;
else
data = new T[other.allocated];
used = other.used;
free_when_destroyed = other.free_when_destroyed;
is_sorted = other.is_sorted;
allocated = other.allocated;
for (u32 i=0; i<other.used; ++i)
data[i] = other.data[i];
}
//! Direct access operator
T& operator [](u32 index)
{
_IRR_DEBUG_BREAK_IF(index>=used) // access violation
return data[index];
}
//! Direct access operator
const T& operator [](u32 index) const
{
_IRR_DEBUG_BREAK_IF(index>=used) // access violation
return data[index];
}
//! Gets last frame
const T& getLast() const
{
_IRR_DEBUG_BREAK_IF(!used) // access violation
return data[used-1];
}
//! Gets last frame
T& getLast()
{
_IRR_DEBUG_BREAK_IF(!used) // access violation
return data[used-1];
}
//! Returns a pointer to the array.
//! \return Pointer to the array.
T* pointer()
{
return data;
}
//! Returns a const pointer to the array.
//! \return Pointer to the array.
const T* const_pointer() const
{
return data;
}
//! Returns size of used array.
//! \return Size of elements in the array.
u32 size() const
{
return used;
}
//! Returns amount memory allocated.
//! \return Returns amount of memory allocated. The amount of bytes
//! allocated would be allocated_size() * sizeof(ElementsUsed);
u32 allocated_size() const
{
return allocated;
}
//! Returns true if array is empty
//! \return True if the array is empty, false if not.
bool empty() const
{
return used == 0;
}
//! Sorts the array using heapsort. There is no additional memory waste and
//! the algorithm performs (O) n log n in worst case.
void sort()
{
if (is_sorted || used<2)
return;
heapsort(data, used);
is_sorted = true;
}
//! Performs a binary search for an element, returns -1 if not found.
//! The array will be sorted before the binary search if it is not
//! already sorted.
//! \param element: Element to search for.
//! \return Returns position of the searched element if it was found,
//! otherwise -1 is returned.
s32 binary_search(const T& element)
{
return binary_search(element, 0, used-1);
}
//! Performs a binary search for an element, returns -1 if not found.
//! The array will be sorted before the binary search if it is not
//! already sorted.
//! \param element: Element to search for.
//! \param left: First left index
//! \param right: Last right index.
//! \return Returns position of the searched element if it was found,
//! otherwise -1 is returned.
s32 binary_search(const T& element, s32 left, s32 right)
{
if (!used)
return -1;
sort();
s32 m;
do
{
m = (left+right)>>1;
if (element < data[m])
right = m - 1;
else
left = m + 1;
} while((element < data[m] || data[m] < element) && left<=right);
// this last line equals to:
// " while((element != array[m]) && left<=right);"
// but we only want to use the '<' operator.
// the same in next line, it is "(element == array[m])"
if (!(element < data[m]) && !(data[m] < element))
return m;
return -1;
}
//! Finds an element in linear time, which is very slow. Use
//! binary_search for faster finding. Only works if =operator is implemented.
//! \param element: Element to search for.
//! \return Returns position of the searched element if it was found,
//! otherwise -1 is returned.
s32 linear_search(T& element)
{
for (u32 i=0; i<used; ++i)
if (!(element < data[i]) && !(data[i] < element))
return (s32)i;
return -1;
}
//! Finds an element in linear time, which is very slow. Use
//! binary_search for faster finding. Only works if =operator is implemented.
//! \param element: Element to search for.
//! \return Returns position of the searched element if it was found,
//! otherwise -1 is returned.
s32 linear_reverse_search(T& element)
{
for (s32 i=used-1; i>=0; --i)
if (data[i] == element)
return (s32)i;
return -1;
}
//! Erases an element from the array. May be slow, because all elements
//! following after the erased element have to be copied.
//! \param index: Index of element to be erased.
void erase(u32 index)
{
_IRR_DEBUG_BREAK_IF(index>=used || index<0) // access violation
for (u32 i=index+1; i<used; ++i)
data[i-1] = data[i];
--used;
}
//! Erases some elements from the array. may be slow, because all elements
//! following after the erased element have to be copied.
//! \param index: Index of the first element to be erased.
//! \param count: Amount of elements to be erased.
void erase(u32 index, s32 count)
{
_IRR_DEBUG_BREAK_IF(index>=used || index<0 || count<1 || index+count>used) // access violation
for (u32 i=index+count; i<used; ++i)
data[i-count] = data[i];
used-= count;
}
//! Sets if the array is sorted
void set_sorted(bool _is_sorted)
{
is_sorted = _is_sorted;
}
private:
T* data;
u32 allocated;
u32 used;
bool free_when_destroyed;
bool is_sorted;
};
} // end namespace core
} // end namespace irr
#endif