LIBRARY  ieee;
USE ieee.std_logic_1164.all;


 --TODO implement video on/off to this controller--
entity GAME_VGA is
    port(
        in_clk_50 : in std_logic;      -- vga clock
        in_clk_28: in std_logic;    -- clock to be divided to 1hz
        out_xSync : out std_logic;  -- horizontal sync
        out_ySync : out std_logic;  -- vertical sync
        out_R :  out std_logic_vector(9 downto 0);
        out_G :  out std_logic_vector(9 downto 0);
        out_B :  out std_logic_vector(9 downto 0);
        out_blank : out std_logic;
        out_sync : out std_logic;
        out_clk : out std_logic;
        in_left: in std_logic;
        in_right: in std_logic
        );

end GAME_VGA;

    architecture DRAWING_LOGIC of GAME_VGA is
        signal last_left_state: std_logic;
        signal last_right_state: std_logic;
        signal half_clock: std_logic;
        signal one_hertz: std_logic;
        signal flip: std_logic;
        signal x: integer range 0 to 800 := 0;
        signal y: integer range 0 to 525 := 0;
        signal div: integer range 0 to 700000 := 0;
        signal offset: integer range 0 to 400 := 0;
        signal xSyncEnable: std_logic;
        signal ySyncEnable: std_logic;

        -- horizontal - x
        constant x_visibleArea : natural := 640; -- horizontal visible area
        constant x_frontPorch : natural := 16;  -- horizontal front porch
        constant x_syncPulse : natural := 96;  -- horizontal sync pulse
        constant x_backPorch : natural := 48;  -- horizontal back porch
        constant x_total : natural := 800;

        -- vertical - y
        constant y_visibleArea : natural := 480; -- vertical visible area
        constant y_frontPorch : natural := 10;  -- vertical front porch
        constant y_syncPulse : natural := 2;   -- vertical sync pulse
        constant y_backPorch : natural := 33;  -- vertical back porch
        constant y_total : natural := 525;

        signal color: std_logic_vector(2 downto 0) := "000";

        begin
            out_sync <= '0';
            out_blank <= '1';
            color <= "010";
            out_xSync <= xSyncEnable;
            out_ySync <= ySyncEnable;
            out_clk <= half_clock;

        -- HALFING THE CLOCK --
        clockScale: process(in_clk_50)
        begin
            if in_clk_50'event and in_clk_50 = '1' then
                half_clock <= not half_clock;
            end if;
        end process clockScale;

        -- ONE HERTZ CLOCK --
        divCounter: process(in_clk_28)
        begin
            if in_clk_28'event and in_clk_28 = '1' then
                if div = 70000 then
                    div <= 0;
                    one_hertz <= not one_hertz;
                else
                    div <= div + 1;
                end if;
            end if;
        end process divCounter;


        -- SIGNAL TIMING --

        sig_timing: process(half_clock)
        begin
            if half_clock'event and half_clock = '1' then
                if x = x_total then

                    x <= 0;
                    y <= y + 1;

                    if y = y_total then
                        y <= 0;
                    else
                        y <= y + 1;
                    end if;
                else
                    x <= x + 1;
                end if;
            end if;
        end process sig_timing;


        offset_maker: process(one_hertz)
        begin
            if rising_edge(one_hertz) then
                if in_left = '1' and last_left_state = '0' then
                    offset <= offset + 1;
                elsif in_right = '1' and last_right_state = '1'  then
                    offset <= offset - 1;
                end if;
                last_right_state <= in_right;
                last_left_state <= in_left;
            end if;
        end process offset_maker;

        vga_sync: process (half_clock)
        begin

            if half_clock'event and half_clock = '1' then
                if x >= (x_visibleArea + x_frontPorch) and x < (x_visibleArea + x_frontPorch + x_syncPulse)  then --96 points
                    xSyncEnable <= '0';
                else
                    xSyncEnable <= '1';
                end if;

                if y >= (y_visibleArea + y_frontPorch) and y < (y_visibleArea + y_frontPorch + y_syncPulse) then --2 points
                    ySyncEnable <= '0';
                else
                    ySyncEnable <= '1';
                end if;
            end if;
        end process vga_sync;

--
--        draw: process(half_clock)
--            begin
--                if half_clock'event and half_clock = '1' then
--                        out_R(9) <= '0';
--                        out_G(9) <= '0';
--                        out_B(9) <= '0';
--
--                end if;
--            end process draw;

        try_foreground: process(half_clock)
            begin
                if half_clock'event and half_clock = '1' then

                    if( x >=  (0 + offset) and x < (100 + offset) and y >= 200  and y < 300) and x < 640 and y < 480 then
                        out_R(8) <= '1';
                        out_G(8) <= '0';
                        out_B(8) <= '1';

                        out_R(6) <= '1';
                        out_G(6) <= '0';
                        out_B(6) <= '1';
                    else
                        out_R(8) <= '0';
                        out_B(8) <= '0';

                        out_R(6) <= '0';
                        out_B(6) <= '0';
                    end if;
                end if;
            end process try_foreground;

end DRAWING_LOGIC;