-------------------------------------------------------------------------------
-- Title       : palet
-- Project     : 
-------------------------------------------------------------------------------
-- File        : palet.vhd
-- Author      : Frederic Lochon
-- Company     : 
-- Last update : 2002/12/10
-- Platform    : 
-------------------------------------------------------------------------------
-- Description :
-- detection approximative de zones de couleur (a choisir au moment de la
-- synthese)
-------------------------------------------------------------------------------
-- Modification history :
-- 2002/11/28 : created
-------------------------------------------------------------------------------

LIBRARY ieee, work;
USE ieee.std_logic_1164.ALL;
USE ieee.numeric_std.ALL;
USE ieee.std_logic_unsigned.all;

ENTITY palet IS
  
  GENERIC (
    code_red	: integer range 0 to 1 := 1;
    code_gre	: integer range 0 to 1 := 0;
    code_blu	: integer range 0 to 1 := 0;

    seuilpixel  : integer := 10;
    seuilligne  : integer :=  3;

	 hauteur_min : integer := 2;
	 largeur_min : integer := 7
    );

  PORT (
    cpt_line	: IN  integer range 0 to 511;
    cpt_row	: IN  integer range 0 to 1023;

    cpt_row_out : OUT integer range 0 to 1023;
    cpt_line_out: OUT integer range 0 to 511;

    red_out     : OUT std_logic;
    gre_out     : OUT std_logic;
    blu_out     : OUT std_logic;

    red_in      : IN  std_logic;
    gre_in      : IN  std_logic;
    blu_in      : IN  std_logic;

--     droite      : OUT integer range 0 to 1023;
--     gauche      : OUT integer range 0 to 1023;
--     haut        : OUT integer range 0 to 511;
--     bas         : OUT integer range 0 to 511;
    choix       : IN  std_logic_vector(1 downto 0);
    donnee      : OUT std_logic_vector(11 downto 0);
    
    en_win      : IN  std_logic;
    so_win      : OUT std_logic;
    
    reset_n     : IN  std_logic;
    clock       : IN  std_logic
    );
  
END palet ;

ARCHITECTURE deux_d OF palet IS 
  
  signal s_droite, s_gauche: integer range 0 to 1023;
  signal s_haut, s_bas : integer range 0 to 511;
  signal row_start : integer range 0 to 1023;  -- pixel
  signal line_start : integer range 0 to 511;  -- hs
  signal last1 : std_logic;
  signal match : std_logic;

  function itol(i: integer range 0 to 1) return std_logic is
  variable l: std_logic := '0';
  begin
    if i=1 then
      l:='1';
    end if;
    return l;
  end;

  BEGIN

  colormatch : process (red_in, gre_in, blu_in)
  begin
    if red_in=itol(code_red) and gre_in=itol(code_gre) and blu_in=itol(code_blu) then
      match <= '1';
    else
      match <= '0';
    end if;
  end process;
  
-------------------------------------------------------------------------------
  
  choix_donnee : process (choix, s_gauche, s_droite, s_haut, s_bas)
  begin
    case choix is
      when "00" => donnee <= std_logic_vector(to_unsigned(s_gauche,12));
      when "01" => donnee <= std_logic_vector(to_unsigned(s_droite,12));
      when "10" => donnee <= std_logic_vector(to_unsigned(s_haut,12));
      when others => donnee <= std_logic_vector(to_unsigned(s_bas,12));
--       when others => NULL;
    end case;
  end process;
  
-------------------------------------------------------------------------------
  findball : process (clock, reset_n)
  begin
    if (reset_n='0') then
      s_droite     <= 0;
      s_gauche     <= 0;
      red_out      <= '0';
      blu_out      <= '0';
      gre_out      <= '0';
      last1        <= '0';
      s_bas        <= 0;
      s_haut       <= 0;
      line_start   <= 0;
      row_start    <= 0;
      
      so_win       <= '0';
      cpt_row_out  <= 0;
      cpt_line_out <= 0;

    elsif (rising_edge(clock)) then
      
-- fenetrage
      if en_win = '1' and row_start=0 and match = '1' then
        s_gauche   <= cpt_row;
        s_droite   <= cpt_row;
        red_out    <= '0';              -- pixel bleu: demarrage du palet
        gre_out    <= '0';
        blu_out    <= '1';
        last1      <= '1';
        s_bas      <= cpt_line;
        s_haut     <= cpt_line;
        line_start <= cpt_line;
        row_start  <= cpt_row;
      elsif en_win = '1' and row_start=0 then
        s_gauche   <= s_gauche;
        s_droite   <= s_droite;
        red_out    <= red_in;           -- rien de special
        gre_out    <= gre_in;
        blu_out    <= blu_in;
        last1      <= last1;
        s_bas      <= s_bas;
        s_haut     <= s_haut;
        line_start <= line_start;
        row_start  <= row_start;
      elsif en_win = '1' and match = '1' and last1 = '1' and line_start = cpt_line then 
        if cpt_row > s_droite then
          s_droite <= cpt_row;
        else
          s_droite <= s_droite;
        end if;
        s_gauche   <= s_gauche;
        red_out    <= itol(code_red);          -- pixel bleu-ciel / violet : suite de pixel dans
        gre_out    <= itol(code_gre);          -- une meme ligne
        blu_out    <= '1';
        last1      <= last1;
        s_bas      <= s_bas;
        s_haut     <= s_haut;
        line_start <= line_start;
        row_start  <= row_start;
        
      elsif en_win = '1' and match = '1' and abs(cpt_row-row_start)<seuilpixel and ( cpt_line-line_start < seuilligne ) then
        if cpt_row < s_gauche then
          s_gauche <= cpt_row;
        else
          s_gauche <= s_gauche;
        end if;
        if cpt_row > s_droite then
          s_droite <= cpt_row;
        else
          s_droite <= s_droite;
        end if;
        red_out    <= '1';              -- pixel jaune: nouvelle ligne pas
        gre_out    <= '1';              -- loin (meme palet)
        blu_out    <= '0';
        last1      <= '1';
        s_haut     <= s_haut;
        s_bas      <= cpt_line;
        line_start <= cpt_line;
        row_start  <= cpt_row;
        
      elsif en_win = '1' then
        s_gauche   <= s_gauche;
        s_droite   <= s_droite;
        red_out    <= red_in;           -- c'est meme pas la bonne couleur
        gre_out    <= gre_in;
        blu_out    <= blu_in;
        last1      <= '0';
        s_bas      <= s_bas;
        s_haut     <= s_haut;
        line_start <= line_start;
        row_start  <= row_start;
      
		elsif en_win = '1' and ( cpt_line - line_start > seuilligne) and
		      ( ((s_bas-s_haut) < hauteur_min) ) then
		  s_gauche   <= 0;
		  s_droite   <= 0;
		  s_haut     <= 0;
        s_bas      <= 0;
		  line_start <= 0;
		  row_start  <= 0;
		  last1      <= '0';
		  red_out    <= red_in;
		  gre_out    <= gre_in;
		  blu_out    <= blu_in;
		  
-- hors fenetrage
      else
        s_gauche   <= s_gauche;
        s_droite   <= s_droite;
        red_out    <= '0';              -- hors fenetre, on fait du noir
        gre_out    <= '0';
        blu_out    <= '0';
        last1      <= '0';              -- hum... faudra verifier ca... 
        s_bas      <= s_bas;
        s_haut     <= s_haut;
        line_start <= line_start;
        row_start  <= row_start;        
      end if;

      cpt_row_out  <= cpt_row;          -- on fait suivre les valeurs au palet
      cpt_line_out <= cpt_line;         -- suivant
      so_win       <= en_win;
    end if;

  end process;

end deux_d;