background.vhd

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

entity background is
    Port (
		switch : in std_logic;
		X : in integer range 0 to 640;
		Y : in integer range 0 to 480;
		rgb_out : out STD_LOGIC_VECTOR (2 downto 0);
		clk25 : in bit);
end background;

architecture Behavioral of background is

	component farbwechsel
		Port (
			rgb_out : out STD_LOGIC_VECTOR (2 downto 0);
			clk25 : in bit);
	end component;
  
	signal chosen_background : STD_LOGIC_VECTOR (1 downto 0);
	signal rgb_farbw : STD_LOGIC_VECTOR (2 downto 0);
	signal deltaX : integer range 0 to 320;
	signal deltaY : integer range 0 to 240;
	signal wobble_clock : integer range 0 to 400000 := 0;
	signal wobble : integer range 0 to 64 := 32; 
	signal wobble_growing : bit := '1';
begin

	farbw : farbwechsel port map (
		rgb_out => rgb_farbw,
		clk25 => clk25);
	
	deltaX <= X - 320 when X > 320 else 320 - X; 	
	deltaY <= Y - 240 when Y > 240 else 240 - Y;

	process (clk25)
	begin
	
		if clk25'event and clk25 = '1' then
			chosen_background <= chosen_background + ( '0' & switch);
			
			case chosen_background is
			  
			  -- fussball feld
			  when "00" =>
			    if X = 320 or X = 321 -- mittellinie
			    or ((deltaY * deltaY) + (deltaX * deltaX)) = 10000 -- grosser mittelkreis
			    or ((deltaY * deltaY) + (deltaX * deltaX)) < 82 -- kleiner mittelkreis
			    or X < 3 or X > 637 or Y < 3 or Y > 477 -- aussenrahmen
			    or (((320 - deltaX) * (320 - deltaX)) + (deltaY * deltaY)) = 10000 -- spielerkreise
			    then
			      rgb_out <= "111";
			    else
			      rgb_out <= "000";
			    end if;
			  
			  -- kreise
			  when "01" =>
			    wobble_clock <= wobble_clock + 1;
			    if wobble_clock = 0 then
			      if wobble_growing = '1' then
			        wobble <= wobble + 1;
			      else
			        wobble <= wobble - 1;
			      end if;
			      if wobble > 60 then
			        wobble_growing <= '0';
			      end if;
			      if wobble < 10 then
			        wobble_growing <= '1';
			      end if;
			    end if;
			    if deltaX > 5 and deltaY > 5 and ((((deltaY * deltaY) + (deltaX * deltaX)) MOD 64) > wobble)
			    then
			      if (X < 320 and Y > 240) or (X > 320 and Y < 240) then
			        rgb_out <= "011";
			      else
			        rgb_out <= "101";
			      end if;
			    elsif ((deltaY * deltaY) + (deltaX * deltaX)) < ((61*512) - (wobble * 512))
				 or ((Y * Y) + (deltaX * deltaX)) < (wobble * 512)
				 or (((480 - Y) * (480 - Y)) + (deltaX * deltaX)) < (wobble * 512)
				 or ((deltaY * deltaY) + (X * X)) < (wobble * 512)
				 or ((deltaY * deltaY) + ((640 - X) * (640 - X))) < (wobble * 512)
				 or (((240 - deltaY) * (240 - deltaY)) + ((320 - deltaX) * (320 - deltaX))) < ((61*512) - (wobble * 512))
				 then
			      if (X < 320 and Y > 240) or (X > 320 and Y < 240) then
  			        rgb_out <= "101";
  			      else
  			        rgb_out <= "011";
  			      end if;
  			    else
			      rgb_out <= "000";
			    end if;
			    
			  -- karos
			  when "10" =>
			    if (deltaX MOD 64) < 32 and (deltaY MOD 64) > 32 then
			      rgb_out <= "001";
			    else
			      rgb_out <= "110";
			    end if;
			    
			  -- farbwechsel
			  when others => rgb_out <= rgb_farbw;			
			  
			end case; 		
		end if;
	end process;

end Behavioral;