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-- Company: 
-- Engineer: 
-- 
-- Create Date: 28.06.2021 09:20:00
-- Design Name: 
-- Module Name: VGAControler - Behavioral
-- Project Name: 
-- Target Devices: 
-- Tool Versions: 
-- Description: 
-- 
-- Dependencies: 
-- 
-- Revision:
-- Revision 0.01 - File Created
-- Additional Comments:
-- 
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library IEEE;
use IEEE.STD_LOGIC_1164.ALL;

-- Uncomment the following library declaration if using
-- arithmetic functions with Signed or Unsigned values
--use IEEE.NUMERIC_STD.ALL;

-- Uncomment the following library declaration if instantiating
-- any Xilinx leaf cells in this code.
--library UNISIM;
--use UNISIM.VComponents.all;

entity VGAControler is
    Generic (  HEIGHT    : Natural;
               WIDTH     : Natural;
               X_PulseWidth : Natural;
               X_FrontPorch : Natural;
               X_BackPorch  : Natural;
               Y_PulseWidth : Natural;
               Y_FrontPorch : Natural;
               Y_BackPorch  : Natural              
    );
    Port (     VGA_RED   : out STD_LOGIC_VECTOR (3 downto 0);
               VGA_BLUE  : out STD_LOGIC_VECTOR (3 downto 0);
               VGA_GREEN : out STD_LOGIC_VECTOR (3 downto 0);
               VGA_HS    : out STD_LOGIC;
               VGA_VS    : out STD_LOGIC;
               
               X         : out Natural;
               Y         : out Natural;
               PIXEL_ON  : in STD_LOGIC;
               
               CLK       : in STD_LOGIC;
               RST       : in STD_LOGIC);
end VGAControler;

architecture Behavioral of VGAControler is

    component Compteur is
    Generic (Min : Natural;
             Max : Natural
            );
    Port    (CLK : in STD_LOGIC;
             RST : in STD_LOGIC;
             Value : out Natural;
             Carry : out STD_LOGIC);
    end component;
    
    signal X_pos : Natural := 0;
    signal Y_pos : Natural := 0;
    signal Y_CLK : STD_LOGIC := '0';
    signal Screen_CLK : STD_LOGIC := '0';
    signal active : BOOLEAN := false;

begin

    X_Compteur : Compteur 
    generic map (Min => 0,
                 Max => WIDTH + X_PulseWidth + X_FrontPorch + X_BackPorch - 1)
    port map    (CLK => CLK,
                 RST => RST,
                 Value => X_pos,
                 Carry => Y_CLK);
                 
    Y_Compteur : Compteur 
    generic map (Min => 0,
                 Max => HEIGHT + Y_PulseWidth + Y_FrontPorch + Y_BackPorch - 1)
    port map    (CLK => Y_CLK,
                 RST => RST,
                 Value => Y_pos,
                 Carry => Screen_CLK);
                 
    active <= ((X_pos < WIDTH) and (Y_pos < HEIGHT));
                 
    VGA_RED   <= "0000" when (RST = '0') else 
                 "1000" when ((PIXEL_ON = '0') or (not active)) else 
                 "1111";
    VGA_BLUE  <= "0000" when (RST = '0') else 
                 "1000" when ((PIXEL_ON = '0') or (not active)) else 
                 "1111";
    VGA_GREEN <= "0000" when (RST = '0') else 
                 "1000" when ((PIXEL_ON = '0') or (not active)) else 
                 "1111";
        
    VGA_HS    <= '0' when ((RST = '0') or (X_pos < WIDTH  + X_FrontPorch) or (X_pos >= WIDTH  + X_FrontPorch + X_PulseWidth)) else 
                 '1';
    VGA_VS    <= '0' when ((RST = '0') or (Y_pos < HEIGHT + Y_FrontPorch) or (Y_pos >= HEIGHT + Y_FrontPorch + Y_PulseWidth)) else 
                 '1';

    X <= X_pos;
    Y <= Y_pos;

end Behavioral;