Diff: irrArray.h

Revision:

0:41a49a73580c

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/irrArray.h	Wed Nov 17 20:19:41 2010 +0000
@@ -0,0 +1,443 @@
+// 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:
+
+	array()
+		: data(0), used(0), allocated(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), used(0), allocated(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