array3d.h

游戏开发数据结构Data Structures for Game Programmers

// ============================================================================
// Data Structures For Game Programmers
// Ron Penton
// Array3D
// This is the 3D Array Class.
// ============================================================================
#ifndef ARRAY3D_H
#define ARRAY3D_H


template <class Datatype>
class Array3D
{
public:

// -------------------------------------------------------
// Name:        Array3D::Array3D
// Description: This creates the 2d array using a sinle
//              linear array.
// -------------------------------------------------------
    Array3D( int p_width, int p_height, int p_depth )
    {
        // create a new array
        m_array = new Datatype[ p_width * p_height * p_depth ];

        // set the size variables
        m_width = p_width;
        m_height = p_height;
        m_depth = p_depth;
    }


// -------------------------------------------------------
// Name:        Array3D::~Array3D
// Description: This destructs the array.
// -------------------------------------------------------
    ~Array3D()
    {
        // if the array exists, delete it.
        if( m_array != 0 )
            delete[] m_array;
        m_array = 0;
    }

 
// -------------------------------------------------------
// Name:        Array3D::Get
// Description: This retrieves the item at the given
//              index.
// -------------------------------------------------------
    Datatype& Get( int p_x, int p_y, int p_z )
    {
        return m_array[ (p_z * m_width * m_height) + 
                        (p_y * m_width) + 
                        p_x ];
    }



// -------------------------------------------------------
// Name:        Array3D::Resize
// Description: This resizes the array.
// -------------------------------------------------------
    void Resize( int p_width, int p_height, int p_depth )
    {
        // create a new array.
        Datatype* newarray = new Datatype[ p_width * p_height * p_depth ];

        if( newarray == 0 )
            return;

        // create the three coordinate variables and the four temp 
        // variables.
        int x, y, z, t1, t2, t3, t4;

        // determine the minimum of all dimensions.
        int minx = (p_width < m_width ? p_width : m_width);
        int miny = (p_height < m_height ? p_height : m_height);
        int minz = (p_depth < m_depth ? p_depth : m_depth);

        // loop through each cell and copy everything over.
        for( z = 0; z < minz; z++ )
        {
            // precalculate the outter term (z) of the 
            // access algorithm
            t1 = z * p_width * p_height;
            t2 = z * m_width * m_height;
            for( y = 0; y < miny; y++ )
            {
                // precalculate the middle term (y) of the
                // access algorithm
                t3 = y * p_width;
                t4 = y * m_width;
                for( x = 0; x < minx; x++ )
                {
                    // move the data to the new array.
                    newarray[ t1 + t3 + x ] = m_array[ t2 + t4 + x ];
                }
            }
        }

        // delete the old array.        
        if( m_array != 0 )
            delete[] m_array;

        // set the new array, and the width and height.
        m_array = newarray;
        m_width = p_width;
        m_height = p_height;
        m_depth = p_depth;
    }



// -------------------------------------------------------
//  Name:         Array3D::Size
//  Description:  gets the size of the array.
//  Return Value: the size of the array.
// -------------------------------------------------------
    int Size()
    {
        return m_width * m_height * m_depth;
    }


// -------------------------------------------------------
//  Name:         Array3D::Width
//  Description:  gets the width of the array.
//  Return Value: the width of the array.
// -------------------------------------------------------
    int Width()
    {
        return m_width;
    }


// -------------------------------------------------------
//  Name:         Array3D::Height
//  Description:  gets the height of the array.
//  Return Value: the height of the array.
// -------------------------------------------------------
    int Height()
    {
        return m_height;
    }


// -------------------------------------------------------
//  Name:         Array3D::Depth
//  Description:  gets the depth of the array.
//  Return Value: the depth of the array.
// -------------------------------------------------------
    int Depth()
    {
        return m_depth;
    }

// -------------------------------------------------------
// Name:        Array3D::m_array
// Description: This is a pointer to the array.
// -------------------------------------------------------
    Datatype* m_array;

// -------------------------------------------------------
// Name:        Array3D::m_width
// Description: the current width of the array.
// -------------------------------------------------------
    int m_width;

// -------------------------------------------------------
// Name:        Array3D::m_height
// Description: the current height of the array.
// -------------------------------------------------------
    int m_height;

// -------------------------------------------------------
// Name:        Array3D::m_depth
// Description: the current depth of the array.
// -------------------------------------------------------
    int m_depth;
};




#endif