WIP foreground sprite + `std_logic_vector` -> `unsigned` mess

1 files changed, 12 insertions, 8 deletions

diff --git a/basys3/basys3.srcs/ppu_consts.vhd b/basys3/basys3.srcs/ppu_consts.vhd
index 89b7a7a..722954d 100644
--- a/basys3/basys3.srcs/ppu_consts.vhd
+++ b/basys3/basys3.srcs/ppu_consts.vhd
@@ -2,7 +2,7 @@
 package ppu_consts is
 	constant PPU_RAM_BUS_ADDR_WIDTH : natural := 16; -- RAM bus address width
 	constant PPU_RAM_BUS_DATA_WIDTH : natural := 16; -- RAM bus data width
-	constant PPU_FG_SPRITE_COUNT : natural := 128; -- amount of foreground sprites
+	constant PPU_FG_SPRITE_COUNT : natural := 128; -- foreground sprites
 	constant PPU_COLOR_OUTPUT_DEPTH : natural := 4; -- VGA output channel depth
 	constant PPU_PALETTE_COLOR_WIDTH : natural := 3; -- palette index width (within sprite)
 	constant PPU_PALETTE_INDEX_WIDTH : natural := 3; -- palette index width (palette table)
@@ -17,18 +17,22 @@ package ppu_consts is
 	constant PPU_PAL_DATA_WIDTH : natural := 12; -- palette memory ram bus data width
 	constant PPU_AUX_ADDR_WIDTH : natural := 1; -- auxiliary memory ram bus address width
 	constant PPU_AUX_DATA_WIDTH : natural := 16; -- auxiliary memory ram bus data width
-	constant PPU_POS_H_WIDTH : natural := 9; -- amount of bits for horizontal screen offset
-	constant PPU_POS_V_WIDTH : natural := 8; -- amount of bits for vertical screen offset
+	constant PPU_POS_H_WIDTH : natural := 9; -- bits for horizontal screen offset
+	constant PPU_POS_V_WIDTH : natural := 8; -- bits for vertical screen offset
 	constant PPU_SPRITE_WIDTH : natural := 16; -- sprite width (pixels)
 	constant PPU_SPRITE_HEIGHT : natural := 16; -- sprite height (pixels)
+	constant PPU_SPRITE_PIDX_WIDTH : natural := 8; -- bits needed to identify horizontal and vertical pixel within sprite
 	constant PPU_SPRITE_POS_H_WIDTH: natural := 4; -- bits needed to identify horizontal pixel within sprite
 	constant PPU_SPRITE_POS_V_WIDTH: natural := 4; -- bits needed to identify vertical pixel within sprite
 	constant PPU_SCREEN_WIDTH : natural := 320; -- absolute screen width (pixels)
 	constant PPU_SCREEN_HEIGHT : natural := 240; -- absolute screen height (pixels)
-	constant PPU_BG_CANVAS_TILES_H : natural := 40; -- amount of tiles (horizontally) on background canvas
-	constant PPU_BG_CANVAS_TILES_V : natural := 30; -- amount of tiles (vertically) on background canvas
-	constant PPU_TILE_INDEX_WIDTH : natural := 10; -- amount of bits needed to index a tile from TMM memory
-	constant PPU_PIXELS_PER_TILE_WORD : natural := 5; -- amount of pixels defined in one word in TMM memory
-	constant PPU_SPRITE_PIXELS_PER_WORD : natural := 52; -- amount of words needed for a single sprite
+	constant PPU_BG_CANVAS_TILES_H : natural := 40; -- tiles (horizontally) on background canvas
+	constant PPU_BG_CANVAS_TILES_V : natural := 30; -- tiles (vertically) on background canvas
+	constant PPU_BG_CANVAS_TILE_H_WIDTH : natural := 6; -- bits needed to describe horizontal bg tile index (grid coordinates)
+	constant PPU_BG_CANVAS_TILE_V_WIDTH : natural := 5; -- bits needed to describe vertical bg tile index (grid coordinates)
+	constant PPU_TILE_INDEX_WIDTH : natural := 10; -- bits needed to index a tile from TMM memory
+	constant PPU_PIXELS_PER_TILE_WORD : natural := 5; -- pixels defined in one word in TMM memory
+	constant PPU_SPRITE_PIXELS_PER_WORD : natural := 52; -- words needed for a single sprite
+	constant PPU_PIXEL_BIT_WIDTH : natural := 3; -- bits needed to identify pixel in TMM word
 end package ppu_consts;