Merge branch 'dev' into ppu-interface

1 files changed, 24 insertions, 0 deletions

diff --git a/basys3/basys3.srcs/ppu_sprite_transform.vhd b/basys3/basys3.srcs/ppu_sprite_transform.vhd
new file mode 100644
index 0000000..f94616c
--- /dev/null
+++ b/basys3/basys3.srcs/ppu_sprite_transform.vhd
@@ -0,0 +1,24 @@
+library ieee;
+library work;
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+use work.ppu_consts.all;
+
+entity ppu_sprite_transform is port( -- flip sprites
+	XI : in unsigned(PPU_SPRITE_POS_H_WIDTH-1 downto 0); -- pixel position relative to tile
+	YI : in unsigned(PPU_SPRITE_POS_V_WIDTH-1 downto 0); -- pixel position relative to tile
+	FLIP_H, FLIP_V : in std_logic; -- flip sprite
+	XO : out unsigned(PPU_SPRITE_POS_H_WIDTH-1 downto 0); -- new pixel position relative to tile
+	YO : out unsigned(PPU_SPRITE_POS_V_WIDTH-1 downto 0)); -- new pixel position relative to tile
+end ppu_sprite_transform;
+
+architecture Behavioral of ppu_sprite_transform is
+	signal FLIPPED_X : unsigned(PPU_SPRITE_POS_H_WIDTH-1 downto 0);
+	signal FLIPPED_Y : unsigned(PPU_SPRITE_POS_V_WIDTH-1 downto 0);
+begin
+	FLIPPED_X <= to_unsigned(PPU_SPRITE_WIDTH-1, PPU_SPRITE_POS_H_WIDTH) - XI;
+	FLIPPED_Y <= to_unsigned(PPU_SPRITE_HEIGHT-1, PPU_SPRITE_POS_V_WIDTH) - YI;
+
+	XO <= FLIPPED_X when FLIP_V = '1' else XI;
+	YO <= FLIPPED_Y when FLIP_H = '1' else YI;
+end Behavioral;