/*** GENERAL.C ***/

#include "header.h"

void InitSeed(void)
{
	int	seed;
	time_t	nowtime;
	struct	tm *preztime;

	time(&nowtime);
	preztime = localtime(&nowtime);
	seed = (int)((preztime->tm_sec+1)*(preztime->tm_min+1)*
		(preztime->tm_hour+1)*(preztime->tm_year)*(preztime->tm_year));
	if(seed%2==0) seed++;

	srand48(seed);
}

/*  NEAREST NEIGHBOR MAP:

If the array looks like:
				(00) (01) (02) ....
				(10) (11) (12) ....
				(20) (21) (22) ....
				  .    .    .  .
				  .    .    .   .
				  .    .    .    .

Then the neighbors are:
				Top
			   Left      Right
			   	Bot

All sites have:
	Left:	nabes[0]
	Top:	nabes[1]
	Bot:	nabes[2]
	Right:	nabes[3]

Sites that share a bond can be indexed as follows:
	[ site->nabes[i]->nabes[3-i] = site ]
*/

void Initialize_Arena(Site *arena)
{
	int i, j;
	Site	*origin;

	origin = arena;
	for(i=0;i<NROWS;i++)
	{
		for(j=0;j<NCOLS;j++)
		{
			if(j>0)         arena->nabes[0] = arena - 1;
		  	   else         arena->nabes[0] = arena + NCOLS - 1;

			if(i>0)         arena->nabes[1] = arena - NCOLS;
			   else         arena->nabes[1] = arena + NSITES - NCOLS;

			if(i<(NROWS-1)) arena->nabes[2] = arena + NCOLS;
			   else         arena->nabes[2] = origin + j;

			if(j<(NCOLS-1)) arena->nabes[3] = arena + 1;
			   else         arena->nabes[3] = arena - (NCOLS-1);

			arena++;
		}
	}
}


void Initial_Conditions(Site arena[NROWS][NCOLS])
{
	int	i, j, k=0;
	int	mask[NCOLS];

	for(i=0;i<NCOLS;i++) mask[i] = 0;
	TwoBands(mask,&k,10);
	TwoBands(mask,&k,20);
	TwoBands(mask,&k,40);
	TwoBands(mask,&k,80);

	for(i=0;i<NROWS;i++)
	{
		for(j=0;j<NCOLS;j++)
		{
			arena[i][j].prey = 0;
			if(mask[j])
			{
			 	if(drand48()<0.5)
					arena[i][j].prey = 1;
			}
			arena[i][j].flag = 0;
		}
	}
}

void TwoBands(int *array, int *spot, int size)		/* starting at *spot, setup two bands of */
                        		/* width 'size' */
{
	int i;

	for(i=0;i<size;i++,(*spot)++) array[*spot] = 0;
	for(i=0;i<size;i++,(*spot)++) array[*spot] = 1;
	for(i=0;i<size;i++,(*spot)++) array[*spot] = 0;
	for(i=0;i<size;i++,(*spot)++) array[*spot] = 1;
}