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[/] [graphicsaccelerator/] [trunk/] [Bresenhamer.vhd] - Blame information for rev 2

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1 2 OmarMokhta 
library IEEE;
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use IEEE.STD_LOGIC_1164.ALL;
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use IEEE.numeric_std.all;
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use IEEE.std_logic_unsigned.all;
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entity Bresenhamer is
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    Port ( WriteEnable : out  STD_LOGIC;
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           X : out  STD_LOGIC_VECTOR (9 downto 0);
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           Y : out  STD_LOGIC_VECTOR (8 downto 0);
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           X1 : in  STD_LOGIC_VECTOR (9 downto 0);
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           Y1 : in  STD_LOGIC_VECTOR (8 downto 0);
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           X2 : in  STD_LOGIC_VECTOR (9 downto 0);
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           Y2 : in  STD_LOGIC_VECTOR (8 downto 0);
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                          SS : out  STD_LOGIC_VECTOR (3 downto 0);
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                          Clk : in STD_LOGIC;
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           StartDraw : in  STD_LOGIC;
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                          dbg : out  STD_LOGIC_VECTOR (11 downto 0);
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                          Reset : in  STD_LOGIC);
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end Bresenhamer;
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architecture Behavioral of Bresenhamer is
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signal myX1,myX2 : STD_LOGIC_VECTOR (11 downto 0);
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signal myY1,myY2 : STD_LOGIC_VECTOR (11 downto 0);
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signal p,p0_1,p0_2,p0_3,p0_4,p0_5,p0_6,p0_7,p0_8 : STD_LOGIC_VECTOR (11 downto 0);
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signal p_1,p_2,p_3,p_4,p_5,p_6,p_7,p_8 : STD_LOGIC_VECTOR (11 downto 0);
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signal ndx,ndy : STD_LOGIC_VECTOR (11 downto 0);
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signal dx,dy,t_2dx,t_2dy,neg_dx,neg_dy,t_2neg_dx,t_2neg_dy : STD_LOGIC_VECTOR (11 downto 0);
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signal dx_minus_dy : STD_LOGIC_VECTOR (11 downto 0);
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signal minus_dx_minus_dy : STD_LOGIC_VECTOR (11 downto 0);
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signal minus_dx_plus_dy : STD_LOGIC_VECTOR (11 downto 0);
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signal dx_plus_dy : STD_LOGIC_VECTOR (11 downto 0);
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signal State : STD_LOGIC_VECTOR(3 downto 0) := "0000";
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signal condX1X2,condY1Y2 : STD_LOGIC;
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constant IDLE : STD_LOGIC_VECTOR(3 downto 0) := "0000";
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constant INIT : STD_LOGIC_VECTOR(3 downto 0) := "0001";
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constant CASE1 : STD_LOGIC_VECTOR(3 downto 0) := "0010";
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constant CASE2 : STD_LOGIC_VECTOR(3 downto 0) := "0011";
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constant CASE3 : STD_LOGIC_VECTOR(3 downto 0) := "0100";
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constant CASE4 : STD_LOGIC_VECTOR(3 downto 0) := "0101";
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constant CASE5 : STD_LOGIC_VECTOR(3 downto 0) := "0110";
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constant CASE6 : STD_LOGIC_VECTOR(3 downto 0) := "0111";
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constant CASE7 : STD_LOGIC_VECTOR(3 downto 0) := "1000";
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constant CASE8 : STD_LOGIC_VECTOR(3 downto 0) := "1001";
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constant CLEAR : STD_LOGIC_VECTOR(3 downto 0) := "1010";
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signal ccounter : STD_LOGIC_VECTOR (18 downto 0) := "0000000000000000000";
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begin
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ndx <= ("00" & X2)-("00" & X1);
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ndy <= ("000" & Y2)-("000" & Y1);
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neg_dx <= 0-dx;
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neg_dy <= 0-dy;
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dbg <= p;
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dx_minus_dy <= dx+neg_dy;
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minus_dx_minus_dy <= neg_dx+neg_dy;
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minus_dx_plus_dy <= neg_dx+dy;
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dx_plus_dy <= dx+dy;
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t_2dy <= dy(10 downto 0) & '0';
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t_2dx <= dx(10 downto 0) & '0';
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t_2neg_dy <= neg_dy(10 downto 0) & '0';
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t_2neg_dx <= neg_dx(10 downto 0) & '0';
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p0_1 <= t_2dy+neg_dx;
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p0_2 <= t_2dx+neg_dy;
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p0_3 <= t_2neg_dx+dy;
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p0_4 <= t_2dy+neg_dx;
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p0_5 <= t_2neg_dy+dx;
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p0_6 <= t_2neg_dx+dy;
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p0_7 <= t_2dx+neg_dy;
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p0_8 <= t_2neg_dy+dx;
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p_1 <= p+t_2dy when p(11)='1' else p+t_2dy+t_2neg_dx;
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p_2 <= p+t_2dx when p(11)='1' else p+t_2dx+t_2neg_dy;
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p_3 <= p+t_2neg_dx when p(11)='1' else p+t_2neg_dx+t_2neg_dy;
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p_4 <= p+t_2dy when p(11)='1' else p+t_2dy+t_2dx;
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p_5 <= p+t_2neg_dy when p(11)='1' else p+t_2neg_dy+t_2dx;
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p_6 <= p+t_2neg_dx when p(11)='1' else p+t_2neg_dx+t_2dy;
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p_7 <= p+t_2dx when p(11)='1' else p+t_2dx+t_2dy;
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p_8 <= p+t_2neg_dy when p(11)='1' else p+t_2neg_dy+t_2neg_dx;
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X <= ccounter(9 downto 0) when State = CLEAR else myX1(9 downto 0);
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Y <= ccounter(18 downto 10) when State = CLEAR else myY1(8 downto 0);
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SS <= State;
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WriteEnable <= '0' when State = IDLE or State = INIT else '1';
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process (Clk) begin
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        if (rising_edge(Clk)) then
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                if (State = IDLE) then
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                        if (Reset = '1') then
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                                State <= CLEAR;
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                                ccounter <= (others=>'0');
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                        elsif (StartDraw = '1') then
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                                myX1(9 downto 0) <= X1;
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                                myX1(11 downto 10) <= "00";
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                                myY1(8 downto 0) <= Y1;
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                                myY1(11 downto 9) <= "000";
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                                myX2(9 downto 0) <= X2;
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                                myX2(11 downto 10) <= "00";
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                                myY2(8 downto 0) <= Y2;
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                                myY2(11 downto 9) <= "000";
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                                dx <= ndx;
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                                dy <= ndy;
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                                State <= INIT;
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                        end if;
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                elsif (State = INIT) then
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                        if (dx(11) = '0' and dy(11) = '0' and dx_minus_dy(11) = '0') then
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                                State <= CASE1;
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                                p <= p0_1;
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                        elsif (dx(11) = '0' and dy(11) = '0' and dx_minus_dy(11) = '1') then
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                                State <= CASE2;
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                                p <= p0_2;
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                        elsif (dx(11) = '1' and dy(11) = '0' and minus_dx_minus_dy(11) = '1') then
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                                State <= CASE3;
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                                p <= p0_3;
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                        elsif (dx(11) = '1' and dy(11) = '0' and minus_dx_minus_dy(11) = '0') then
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                                State <= CASE4;
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                                p <= p0_4;
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                        elsif (dx(11) = '1' and dy(11) = '1' and minus_dx_plus_dy(11) = '0') then
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                                State <= CASE5;
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                                p <= p0_5;
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                        elsif (dx(11) = '1' and dy(11) = '1' and minus_dx_plus_dy(11) = '1') then
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                                State <= CASE6;
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                                p <= p0_6;
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                        elsif (dx(11) = '0' and dy(11) = '1' and dx_plus_dy(11) = '1') then
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                                State <= CASE7;
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                                p <= p0_7;
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                        else
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                                State <= CASE8;
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                                p <= p0_8;
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                        end if;
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                elsif (State = CASE1) then
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                        if (myX1 = myX2) then
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                                State <= IDLE;
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                        else
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                                myX1 <= myX1 + 1;
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                                p <= p_1;
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                                if (P(11) = '0') then
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                                        myY1 <= myY1 + 1;
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                                end if;
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                        end if;
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                elsif (State = CASE2) then
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                        if (myY1 = myY2) then
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                                State <= IDLE;
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                        else
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                                myY1 <= myY1 + 1;
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                                p <= p_2;
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                                if (P(11) = '0') then
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                                        myX1 <= myX1 + 1;
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                                end if;
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                        end if;
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                elsif (State = CASE3) then
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                        if (myY1 = myY2) then
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                                State <= IDLE;
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                        else
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                                myY1 <= myY1 + 1;
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                                p <= p_3;
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                                if (P(11) = '0') then
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                                        myX1 <= myX1 - 1;
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                                end if;
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                        end if;
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                elsif (State = CASE4) then
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                        if (myX1 = myX2) then
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                                State <= IDLE;
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                        else
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                                myX1 <= myX1 - 1;
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                                p <= p_4;
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                                if (P(11) = '0') then
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                                        myY1 <= myY1 + 1;
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                                end if;
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                        end if;
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                elsif (State = CASE5) then
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                        if (myX1 = myX2) then
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                                State <= IDLE;
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                        else
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                                myX1 <= myX1 - 1;
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                                p <= p_5;
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                                if (P(11) = '0') then
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                                        myY1 <= myY1 - 1;
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                                end if;
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                        end if;
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                elsif (State = CASE6) then
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                        if (myY1 = myY2) then
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                                State <= IDLE;
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                        else
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                                myY1 <= myY1 - 1;
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                                p <= p_6;
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                                if (P(11) = '0') then
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                                        myX1 <= myX1 - 1;
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                                end if;
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                        end if;
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                elsif (State = CASE7) then
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                        if (myY1 = myY2) then
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                                State <= IDLE;
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                        else
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                                myY1 <= myY1 - 1;
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                                p <= p_7;
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                                if (P(11) = '0') then
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                                        myX1 <= myX1 + 1;
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                                end if;
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                        end if;
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                elsif (State = CASE8) then
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                        if (myX1 = myX2) then
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                                State <= IDLE;
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                        else
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                                myX1 <= myX1 + 1;
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                                p <= p_8;
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                                if (P(11) = '0') then
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                                        myY1 <= myY1 - 1;
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                                end if;
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                        end if;
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                elsif (State = CLEAR) then
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                        ccounter <= ccounter + 1;
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                        if (ccounter = "1111111111111111111") then
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                                State <= IDLE;
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                        end if;
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                end if;
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        end if;
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end process;
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end Behavioral;

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