Somewhat proper working script :)

documentation/lua/smb2.lua

@@ -1,12 +1,15 @@
 -- unfinished mario bros 2 script
--- shows (proper!) grid for horizontal levels (b0rks in vertical levels for now)
+-- shows (proper!) grid and contents. disable grid by setting variable to false
 -- shows any non-air grid's tile-id
--- is sloooow :p
+-- can be heavy on light systems
 
 -- Super Mario Bros. 2 (U) (PRG0) [!].rom
 -- qFox
 -- 31 july 2008
 
+local angrybirdo = false; -- makes birdo freak, but can skew other creatures with timing :)
+local drawgrid = true; -- draws a green grid
+
 local function box(x1,y1,x2,y2,color)
 	-- gui.text(50,50,x1..","..y1.." "..x2..","..y2);
 	if (x1 > 0 and x1 < 0xFF and x2 > 0 and x2 < 0xFF and y1 > 0 and y1 < 239 and y2 > 0 and y2 < 239) then
@@ -24,7 +27,7 @@ local function toHexStr(n)
 end;
 
 while (true) do
-	if (memory.readbyte(0x0010) > 0x81) then memory.writebyte(0x0010, 0x6D); end; -- birdo fires eggs constantly :p
+	if (angrybirdo and memory.readbyte(0x0010) > 0x81) then memory.writebyte(0x0010, 0x6D); end; -- birdo fires eggs constantly :p
 	
 	-- px = horzizontal page of current level
 	-- x = page x (relative to current page)
@@ -50,12 +53,84 @@ while (true) do
 		box(playersx, playersy, playersx+16, playersy+16, "green");
 	end;
 
-	text(2,10,"x:"..screenoffsetx);
+	if (memory.readbyte(0x00D8) == 0) then -- not scrolling vertically
-	text(2,25,"y: "..screenoffsety);
+		-- show environment
+		-- i have playerrx, which is my real position in this level
+		-- i have the level, which is located at 0x6000 (the SRAM)
+		-- each tile (denoted by one byte) is 16x16 pixels
+		-- each screen is 15 tiles high and about 16 tiles wide
+		-- to get the right column, we add our playerrx/16 to 0x6000
+		-- to be exact:
+		-- 0x6000 + (math.floor(playerrx/16) * 0xF0) + math.mod(playerx,0x0F)
+		
+		local levelstart = 0x6000; -- start of level layout in RAM
+	
+	  -- ok, here we have two choices. either this is a horizontal level or
+	  -- it is a vertical level. We have no real way of checking this, but
+	  -- luckily levels are either horizontal or vertical :)
+	  -- so there are three possibilities
+	  -- 1: you're in 0:0, no worries
+	  -- 2: you're in x:0, you're in a horizontal level
+	  -- 3: you're in 0:y, you're in a vertical level
+	  
+	
+		local addleftcrap = math.mod(screenoffsetx,16)*-1; -- works as padding to keep the grid aligned
+		local leftsplitrx = (memory.readbyte(0x04BE)*0x100) + (screenoffsetx + addleftcrap); -- column start left. add addleftcrap to iterative stuff to build up
+		local addtopcrap = math.mod(screenoffsety,15); -- works as padding to keep the grid aligned
+		local columns = math.floor(leftsplitrx/16); -- column x of the level is on the left side of the screen
+		
+		if (drawgrid) then -- print grid?
+			for i=0,15 do
+				-- text(addleftcrap+(i*16)-1, 37, toHexStr(columns+i)); -- print colnumber in each column
+				for j=0,17 do
+					box(addleftcrap+(i*16), addtopcrap+(j*16), addleftcrap+(i*16)+16, addtopcrap+(j*16)+16, "green"); -- draw green box for each cell
+				end;
+			end;
+		end;
+	
+	-- 42=mushroom if you go sub
+	-- 45=small
+	-- 44=big
+	-- 49=subspace
+	-- 6c=pow
+	-- 4e=cherry
+		
+		local topsplitry = (screenoffsety);
+	
+		-- starting page (might flow into next page). if the number of columns 
+		-- is > 16, its a horizontal level, else its a vertical level. in either 
+		-- case, the other will not up this value.
+		local levelpage = 
+				levelstart + 
+				((math.floor(columns/16))*0xF0) + 
+				(memory.readbyte(0x00CA)*0x100) +
+				topsplitry;
+		local levelcol = math.mod(columns,16); -- this is our starting column
+	
+		--text(10,150,toHexStr(topsplitry).." "..toHexStr(levelcol).." "..toHexStr(levelpage+levelcol).." "..toHexStr(leftsplitrx));
+	
+		for j=0,15 do -- 16 columns
+			if (levelcol + j > 15) then -- go to next page
+				levelpage = levelpage + 0xF0;
+				levelcol = -j;
+			end;
+			for i=0,14 do -- 15 rows
+				local tile = memory.readbyte(levelpage+(levelcol+j)+(i*0x10));
+				if (tile ~= 0x40) then
+					text(-2+addleftcrap+(j*16),5+(i*16),toHexStr(tile));
+				end;
+			end;
+		end;
+	end; -- not scrolling if
+
+	-- print some generic stats
+	text(2,10,"x:"..toHexStr(screenoffsetx));
+	text(2,25,"y: "..toHexStr(screenoffsety));
 	text(230,10,memory.readbyte(0x04C1));
 	text(100,10,"Page: "..playerpx..","..playerpy);
 	text(playersx,playersy,playerrx.."\n"..playery);
 	
+	-- draw enemy info
 	local startpx = 0x0015;
 	local startpy = 0x001F;
 	local startx = 0x0029;
@@ -89,40 +164,8 @@ while (true) do
 					box(esx, esy, esx+16, esy+16, "blue");
 				end;
 			end;
-		end; -- enemy info
+		end;
+	end; -- enemy info
 
-		-- show environment
-		-- i have playerrx, which is my real position in this level
-		-- i have the level, which is located at 0x6000 (the SRAM)
-		-- each tile (denoted by one byte) is 16x16 pixels
-		-- each screen is 15 tiles high and about 16 tiles wide
-		-- to get the right column, we add our playerrx/16 to 0x6000
-		-- to be exact:
-		-- 0x6000 + (math.floor(playerrx/16) * 0xF0) + math.mod(playerx,0x0F)
-		
-		local levelstart = 0x6000; -- start of level layout in RAM
-		local addleftcrap = math.mod(screenoffsetx,16)*-1;
-		local leftsplitrx = (memory.readbyte(0x04BE)*0xFF) + (screenoffsetx + addleftcrap); -- column start left. add addleftcrap to iterative stuff to build up
-		local columns = leftsplitrx/16; -- column x of the level is on the left side of the screen
-		
-		for i=0,15 do
-			text(addleftcrap+(i*16)-1, 37, toHexStr(columns+i));
-			for j=0,17 do
-				box(addleftcrap+(i*16), 1+(j*16), addleftcrap+(i*16)+16, 1+(j*16)+16, "green");
-			end;
-		end;
-		
-		local columntop = levelstart + ((math.floor(columns/16))*0xF0) + math.mod(columns,16);
-		text(10,80,toHexStr(columns).." "..toHexStr(columntop));
-		for i=0,14 do
-			for j=0,15 do
-				local tile = memory.readbyte(columntop+(i*0x10)+j);
-				if (tile ~= 0x40) then
-					text(-2+addleftcrap+(j*16),21+(i*16),toHexStr(tile));
-				end;
-			end;
-		end;
-		
-	end;
 	FCEU.frameadvance();
 end;