terminal/image_generator.vhd

83 lines
2.3 KiB
VHDL

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
use ieee.numeric_std.all;
entity image_generator is
generic (
input_clk: integer
);
port (
clk: in std_logic;
x, y: in std_logic_vector(9 downto 0);
ctrl_up: in std_logic;
ctrl_down: in std_logic;
rgb: out std_logic_vector(23 downto 0)
);
end image_generator;
architecture logic of image_generator is
type glyph is array(0 to 7) of std_logic_vector(7 downto 0);
constant emoji_grin: glyph := (
"00111100",
"01000010",
"10101001",
"10101001",
"10000101",
"10111001",
"01000010",
"00111100"
);
signal glyph_x: integer range 0 to 7;
signal glyph_y: integer range 0 to 7;
signal color: std_logic_vector(23 downto 0);
signal color_index: integer range 0 to 2;
begin
glyph_x <= to_integer(unsigned(x(4 downto 1)));
glyph_y <= to_integer(unsigned(y(4 downto 1)));
process(clk) is
variable last_up: std_logic;
variable last_down: std_logic;
constant debounce_max: integer := input_clk / 50; -- 20ms
variable debounce: integer range 0 to debounce_max := 0;
begin
if rising_edge(clk) then
if debounce = 0 then
if ctrl_up = '1' and last_up = '0' then
if color_index /= 2 then
color_index <= color_index + 1;
end if;
debounce := debounce_max;
end if;
last_up := ctrl_up;
if ctrl_down = '1' and last_down = '0' then
if color_index /= 0 then
color_index <= color_index - 1;
end if;
debounce := debounce_max;
end if;
last_down := ctrl_down;
else
debounce := debounce - 1;
end if;
end if;
end process;
with color_index select color <=
"111111111111111111111111" when 0,
"000000000000000011111111" when 1,
"000101001111111110110100" when 2;
-- actually currently BRG
rgb <=
color when x(4) = y(4) and emoji_grin(glyph_y)(glyph_x) = '1' else
"000000000000000000000000";
end logic;