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-- Company:
-- Engineer:
--
-- Create Date:    14:06:57 01/27/2020
-- Design Name:
-- Module Name:    bitmap - Behavioral
-- Project Name:
-- Target Devices:
-- Tool versions:
-- Description:
--
-- Dependencies:
--
-- Revision:
-- Revision 0.01 - File Created
-- Additional Comments:
--
----------------------------------------------------------------------------------
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

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

entity bitmap is
    Port ( SYS_CLK : in  STD_LOGIC;   --Horloge du gestionnaire de la souris
           DATA : in  STD_LOGIC;  --Données de la souris
           X : out  STD_LOGIC_VECTOR (7 downto 0);  --Déplacement de la souris
           Y : out  STD_LOGIC_VECTOR (7 downto 0);  --Déplacement de la souris
           CLK : in  STD_LOGIC; --Horloge de la souris
           COLOR : out  STD_LOGIC_VECTOR (1 downto 0);  --Définie si on est en écriture/suppression ou rien du tout
           W : out  STD_LOGIC);  --Verifier que tout est valide
end bitmap;

architecture Behavioral of bitmap is

	--Signaux intérmédiaires que l'on va utiliser:
	signal XX : STD_LOGIC_VECTOR (7 downto 0);
	signal YY : STD_LOGIC_VECTOR (7 downto 0);
	signal CCOLOR : STD_LOGIC_VECTOR (1 downto 0);
	signal dirX, dirY : STD_LOGIC;
	signal prevState : STD_LOGIC :='0';
	signal WW : STD_LOGIC :='0';
	signal Err : STD_LOGIC :='0';

	--Déclaration des états
	type sysState is (waitingControl, control, waitingMovX, movX, waitingMovY, movY, endState);
	signal actualState : sysState := waitingControl;
	signal positionCounter : integer range 0 to 9;

	begin


		process(SYS_CLK)

		variable i : integer := 0;
		variable Xcomp : STD_LOGIC_VECTOR (7 downto 0) := "00000000";
		variable Ycomp : STD_LOGIC_VECTOR (7 downto 0) := "00000000";

		begin
			if(rising_edge(SYS_CLK)) then
				if(WW = '1' and Err = '0') then

					--Ecriture de la couleur
					COLOR <= CCOLOR;

					--Calcul de X
					Xcomp := XX;
					if(Xcomp(7)='1')then
							Xcomp(6 downto 0) := "1111111";
					end if;
					Xcomp(7) := '0';

					if(dirX = '0') then
						Xcomp := not Xcomp;
						Xcomp := Xcomp + "00000001";
					end if;

					--Calcul de Y
					Ycomp := YY;
					if(Ycomp(7)='1')then
							Ycomp(6 downto 0) := "1111111";
					end if;
					Ycomp(7) := '0';

					if(dirY = '0') then
						Ycomp := not Ycomp;
						Ycomp := Ycomp + "00000001";
					end if;

					--Ecriture de X et de Y et indication de W
					Y<=Ycomp;
					X<=Xcomp;
					W<='1';

				else
					--Reinitialisation de W
					W<='0';
				end if;
			end if;
		end process;

		--Conversion des datas lignes en data colonnes pour les variables temporaires

		process(CLK)

		variable parity : STD_LOGIC;

		begin

		--Detection du front montant de l'horloge
			if(rising_edge(CLK)) then

				--Détection du bit de start et changement d'état
				if(prevState = '1' and DATA='0') then
					if(actualState=waitingControl) then
						CCOLOR<="00";
						actualState<=control;
						positionCounter <= 1;

					elsif(actualState=waitingMovX) then
						actualState<=movX;
						positionCounter <= 1;

					elsif(actualState=waitingMovY) then
						actualState<=movY;
						positionCounter <= 1;
					end if;

				elsif(DATA = '1') then
					prevState<='1';
				end if;

				--Raz
				if(actualState=endState) then
						actualState<=waitingControl;
						Err<='0';
						WW <= '0';
				end if;

				--Cas de la lecture des boutons de la souris
				if(actualState = control) then
					case(positionCounter) is
						when 0 =>
						when 1 =>
							if(DATA='1') then
								CCOLOR <="11";
							end if;
							parity:=DATA;
						when 2 =>
							if(CCOLOR = "11") then
							else
								if(DATA = '1') then
									CCOLOR <= "10";
								else
									CCOLOR <= "00";
								end if;
							end if;
							parity:=parity xor DATA;
						when 3 => parity:=parity xor DATA;
						when 4 => parity:=parity xor DATA;
						when 5 =>
							if(DATA = '1') then
								dirX<='1';
							else
								dirX<='0';
							end if;
							parity:=parity xor DATA;
						when 6 =>
							if(DATA = '1') then
								dirY<='1';
							else
								dirY<='0';
							end if;
							parity:=parity xor DATA;
						when 7 => parity:=parity xor DATA;
						when 8 => parity:=parity xor DATA;
						when 9 =>
							parity :=parity xor DATA;
							if(parity = '0') then
								Err<='1';
							end if;
							actualState<=waitingMovX;
							prevState<='0';
					end case;

						--Cas du déplacement de la souris dans l'axe X
						elsif(actualState = movX) then

						if(positionCounter >= 1 and positionCounter <=8) then
							XX(positionCounter-1)<=DATA;
							if(positionCounter = 1) then
								parity:= DATA;
							else
								parity := parity xor DATA;
							end if;
						elsif(positionCounter = 9) then
							parity:= parity xor DATA;
								if(parity = '0') then
									Err<='1';
								end if;
								actualState<=waitingMovY;
								prevState<='0';
						end if;

						--Cas du déplacement de la souris dans l'axe Y
					elsif(actualState = movY) then

						if(positionCounter >= 1 and positionCounter <=8) then
							YY(positionCounter-1)<=DATA;
							if(positionCounter = 1) then
								parity:= DATA;
							else
								parity := parity xor DATA;
							end if;
						elsif(positionCounter = 9) then
							parity:= parity xor DATA;
								if(parity = '0') then
									Err<='1';
								end if;
								actualState<=endState;
								prevState<='0';
								WW <= '1';
						end if;

						end if;

				--Incrémentation du compteur
				if(actualState = control or actualState = movX or actualState = movY) then
					if(positionCounter<9) then
							positionCounter <= positionCounter+1;
						else
							positionCounter<=0;
						end if;
				end if;

			end if;

		end process;

end Behavioral;