library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity ball is
    Port ( clk : in std_logic;
			  hcnt : in std_logic_vector(9 downto 0);
			  vcnt : in std_logic_vector(9 downto 0);
           reset : in std_logic;
			  hit_target : in std_logic;
           xsign : in std_logic;  --mouse motion directoin of x
			  dataflag : in std_logic; --the flag of whether data output from mouse
           board_loc : in std_logic_vector(9 downto 0);
           --ball_loc : out std_logic_vector(9 downto 0);
			  ballx : out std_logic_vector(9 downto 0);
			  bally : out std_logic_vector(9 downto 0);
           ballrgb : out std_logic_vector(7 downto 0));
end ball;

architecture Behavioral of ball is


CONSTANT FRAME_WIDTH : INTEGER :=20;
CONSTANT BOARD_WIDTH : INTEGER :=20;
CONSTANT BOARD_LEN : INTEGER :=40;
CONSTANT BALL_R : INTEGER :=5;

signal movclk : std_logic;
signal hcount : std_logic_vector(9 downto 0);
signal vcount : std_logic_vector(9 downto 0);

signal ball_x,ball_y : std_logic_vector(9 downto 0);
signal move_y : std_logic_vector(9 downto 0);
signal move_x,increase,ball_xx : std_logic_vector(10 downto 0);
signal lose : std_logic;--when '1' the ball is losen
signal bang : std_logic; --when '1' the ball hit the board

begin

movclk <= vcount(6);
hcount <= hcnt;
vcount <= vcnt;

ball_x <= ball_xx(10 downto 1);
ballx <= ball_x;
bally <= ball_y;

drawball: process (clk)
begin
  if (clk'event and clk='1') then
    if ((hcount>=(ball_x-5)) and (hcount<=(ball_x+5)) and (vcount>=(ball_y-2)) and (vcount<=(ball_y+2))) or
	   ((hcount>=(ball_x-2)) and (hcount<=(ball_x+2)) and (vcount>=(ball_y-5)) and (vcount<=(ball_y+5))) or
		((hcount>=(ball_x-3)) and (hcount<=(ball_x+3)) and (vcount>=(ball_y-4)) and (vcount<=(ball_y+4))) or
		((hcount>=(ball_x-4)) and (hcount<=(ball_x+4)) and (vcount>=(ball_y-3)) and (vcount<=(ball_y+3))) then
		ballrgb <= "00111111";
	 else
	   ballrgb <= "00000000";
	 end if;
  end if;
end process;

ballmove: process (movclk,reset)
begin
  if reset='0' then
    ball_xx <= "01100100000";
	 ball_y <= "0100101100";
  elsif (movclk'event and movclk='1') then
    if (lose='1' or hit_target='1') then
	   ball_xx <= "01100100000";
	   ball_y <= "0100101100";
	 else
      ball_xx <=ball_xx + move_x;
	   ball_y <=ball_y + move_y;
	 end if;
  end if;
end process;

--select increasment of x direction
process( reset,movclk)
begin
  if reset='0' then
    increase <= "00000000010";
  elsif (movclk'event and movclk='1') then
    increase <= "00000000010";
    if bang='1' then
	   if dataflag='1' then
		  if xsign='1' then
		    increase <= "00000000001";
		  else
		    increase <= "00000000011";
		  end if;
		end if;
	 end if;
  end if;
end process;

movablex: process (movclk,reset)
begin
  if reset='0' then
    move_x <= "00000000010";
  elsif (movclk'event and movclk='1') then
    if (ball_x=(FRAME_WIDTH + BALL_R)) then
	   move_x <= increase;
	 elsif (ball_x=(639-FRAME_WIDTH - BALL_R)) then
	   move_x <= not increase + "1";
	 end if;
  end if;
end process;

movabley: process (movclk,reset)
begin
  if reset='0' then
    move_y <= "0000000001";
	 lose <= '0';
	 bang <= '0';
  elsif (movclk'event and movclk='1') then
    if (ball_y=(FRAME_WIDTH + BALL_R)) then
	   move_y <= "0000000001";
	 elsif (ball_y=(479-FRAME_WIDTH - BOARD_WIDTH - BALL_R)) then
	   if (ball_x>=(board_loc - BOARD_LEN+1)) and (ball_x<=(board_loc + BOARD_LEN-1)) then
	     move_y <= "1111111111";
		  lose <= '0';
		  bang <= '1';
		else
		  lose <= '1';
		  bang <= '0';
		end if;
	 else 
	   lose <= '0';
		bang <= '0';
	 end if;
  end if;
end process;

end Behavioral;