/*
 * Copyright 2012, Haiku, Inc.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *              Aaron Hill <serac@hillvisions.com>
 */


#include "GLifeGrid.h"

#include <math.h>
#include <stdlib.h>
#include <SupportDefs.h>


// ------------------------------------------------------
//  GLifeGrid Class Neighbors Definition
inline int32
GLifeGrid::Neighbors(int32 iRow, int32 iColumn)
{
        return (Occupied(iRow - 1, iColumn - 1) ? 1 : 0)
                   + (Occupied(iRow - 1, iColumn) ? 1 : 0)
                   + (Occupied(iRow - 1, iColumn + 1) ? 1 : 0)
                   + (Occupied(iRow, iColumn - 1) ? 1 : 0)
                   + (Occupied(iRow, iColumn + 1) ? 1 : 0)
                   + (Occupied(iRow + 1, iColumn - 1) ? 1 : 0)
                   + (Occupied(iRow + 1, iColumn) ? 1 : 0)
                   + (Occupied(iRow + 1, iColumn + 1) ? 1 : 0);
}


// ------------------------------------------------------
//  GLifeGrid Class Constructor Definition
GLifeGrid::GLifeGrid(int32 iWidth, int32 iHeight)
        :
        m_iWidth(iWidth),
        m_iHeight(iHeight)
{
        m_pbGrid = new bool[iWidth * iHeight];  
        
        // Randomize new grid
        for(int32 iRow = 0; iRow < iHeight; ++iRow) {
                for(int32 iColumn = 0; iColumn < iWidth; ++iColumn) {
                        // TODO: Allow for customized randomization level
                        m_pbGrid[ (iRow * iWidth) + iColumn] = ((rand() % 6 ) == 0);
                }
        }
}


// ------------------------------------------------------
//  GLifeGrid Class Destructor Definition
GLifeGrid::~GLifeGrid(void)
{
        delete[] m_pbGrid;
}


// ------------------------------------------------------
//  GLifeGrid Class Generation Definition
void
GLifeGrid::Generation(void)
{
        bool* pbTemp = new bool[m_iWidth * m_iHeight];

        for(int32 iRow = 0; iRow < m_iHeight; ++iRow) {
                for(int32 iColumn = 0; iColumn < m_iWidth; ++iColumn) {

                        int32 iNum = Neighbors(iRow, iColumn);
                        pbTemp[(iRow * m_iWidth) + iColumn]
                                = ((iNum == 3) || (Occupied(iRow, iColumn)
                                && iNum >= 2 && iNum <= 3));
                }
        }
        
        // Swap grids
        delete[] m_pbGrid;
        m_pbGrid = pbTemp;
}


// ------------------------------------------------------
//  GLifeGrid Class Occupied Definition
bool
GLifeGrid::Occupied(int32 iRow, int32 iColumn)
{
        int32 iNewRow = (iRow % m_iHeight), iNewColumn = (iColumn % m_iWidth);
        while(iNewRow < 0)
                iNewRow += m_iHeight;
        while(iNewColumn < 0)
                iNewColumn += m_iWidth;
        return m_pbGrid[(iNewRow * m_iWidth) + iNewColumn];
}