/*----------------------Stack routines------------------*/
/*
	Pushes cell p on top of stack t, and returns new top.
*/
tStack	Push( tStack t, tStack p )
{
	p->next = t;
	return	p;
}
/*
	Pops off top elment of stack p, frees up the cell, and
	returns new top.
*/
tStack	Pop( tStack p )
{
	tStack	top;

	top = p->next;
	free( (void *) p );
	return 	top;
}
/*
	Prints the stack, both point index and point coordinates.
*/
void	PrintStack( tStack t )
{
	if (t) { 
	/*	printf("i=%d:", t->i);*/ PrintPoint( P[t->i] ); putchar('\n');
		PrintStack( t->next );
	}
}
/* 
	GetCell returns a pointer to a newly allocated piece of storage
	of type tCell, or exits if no space is available.
*/
tStack	GetCell( void )
{
	tStack	p;

	p = (tStack) malloc( sizeof( struct tCell ) );

	if (p == NULL) {
		printf("Error in GetCell: Out of memory!\n");
		exit(1);
	}
	else	return p;
}