/* bounce1d.c *	purpose	animation with user controlled speed and direction *	note	the handler does the animation *		the main program reads keyboard input *	compile	cc bounce1d.c set_ticker.c -lcurses -o bounce1d */#include	<stdio.h>#include	<curses.h>#include	<signal.h>/* some global settings main and the handler use */#define	MESSAGE	"hello"#define BLANK   "     "int	row;	/* current row		*/int	col;	/* current column	*/int	dir;	/* where we are going	*/int main(){	int	delay;		/* bigger => slower	*/	int	ndelay;		/* new delay		*/	int	c;		/* user input		*/	void	move_msg(int);	/* handler for timer	*/	initscr();	crmode();	noecho();	clear();	row   = 10;		/* start here		*/	col   = 0;	dir   = 1;		/* add 1 to row number	*/	delay = 200;		/* 200ms = 0.2 seconds  */	move(row,col);		/* get into position	*/	addstr(MESSAGE);	/* draw message		*/	signal(SIGALRM, move_msg );	set_ticker( delay );	while(1)	{		ndelay = 0;		c = getch();		if ( c == 'Q' ) break;		if ( c == ' ' ) dir = -dir;		if ( c == 'f' && delay > 2 ) ndelay = delay/2;		if ( c == 's' ) ndelay = delay * 2 ;		if ( ndelay > 0 )			set_ticker( delay = ndelay );	}	endwin();	return 0;}void move_msg(int signum){	signal(SIGALRM, move_msg);	/* reset, just in case	*/	move( row, col );	addstr( BLANK );	col += dir;			/* move to new column	*/	move( row, col );		/* then set cursor	*/	addstr( MESSAGE );		/* redo message		*/	refresh();			/* and show it		*/	/*	 * now handle borders	 */	if ( dir == -1 && col <= 0 )		dir = 1;	else if ( dir == 1 && col+strlen(MESSAGE) >= COLS )		dir = -1;}