#include <stdlib.h>
#include <grass/gis.h>
#include "flag.h"


void FlagClearAll(FLAG *flags)
{
	register int r, c;

	for(r=0; r<flags->nrows; r++)
	{
		for (c=0; c<flags->leng; c++)
		{
			flags->array[r][c] = 0;
		}
	}
}


FLAG *FlagCreate(int nrows, int ncols)
{
	unsigned char *temp;
	FLAG *new_flag;
	register int i;

	new_flag  = (FLAG *)G_malloc(sizeof(FLAG));

	new_flag->nrows = nrows;
	new_flag->ncols = ncols;
	new_flag->leng = (ncols + 7) / 8;
	new_flag->array = (unsigned char **)G_malloc(nrows * sizeof(unsigned char *));

	temp = (unsigned char *)G_calloc(nrows * new_flag->leng, sizeof(unsigned char));

	for (i=0; i<nrows; i++)
	{
		new_flag->array[i] = temp;
		temp += new_flag->leng;
	}

	return(new_flag);
}


void FlagDestroy(FLAG *flags)
{
	G_free (flags->array[0]);
	G_free (flags->array);
	G_free (flags);
}


int FlagGet(FLAG *flags, int row, int col)
{
	return(flags->array[row][col>>3] & (1 << (col & 7)));
}


void FlagSet(FLAG *flags, int row, int col)
{
	flags->array[row][col>>3] |= (1 << (col & 7));
}


void FlagUnset(FLAG *flags, int row, int col)
{
	flags->array[row][col>>3] &= ~(1 << (col & 7));
}