custom_column_pos_actor.lua

-- This actor belongs in ScreenGameplay.
-- Look for "BGAnimations/ScreenGameplay overlay.lua" 
-- or "BGAnimations/ScreenGameplay overlay/default.lua"
-- and add it to the list of actors returned by the file.
t[#t+1]= Def.Actor{
	OnCommand= function(self)
		-- This position table only works for dance single, because supporting
		-- all styles would make this example too big.
		local custom_column_positions= {
			-- Swap up and down for player 1.
			[PLAYER_1]= {-96, 32, -32, 96},
			-- Separate the two sides and swap up and down for player 2.
			[PLAYER_2]= {-128, 64, -64, 128},
		}
		local screen= SCREENMAN:GetTopScreen()
		for i, pn in ipairs(GAMESTATE:GetEnabledPlayers()) do
			local positions= custom_column_positions[pn]
			local player= screen:GetChild("Player" .. ToEnumShortString(pn))
			local notefield= player:GetChild("NoteField")
			-- Some modes like routine might have a player exist without a notefield.
			if notefield then
				-- Version checking.  5.0.12 and 5.1.-3 have different functions.
				if notefield.get_column_actors then
					-- 5.0.12 fights back with hardcoded positions.
					-- To end up in the position we want, we have to set a position
					-- relative to the engine position.
					local engine_positions= {-96, -32, 32, 96}
					local columns= notefield:get_column_actors()
					-- Only move columns if there is a position for each column.
					if #columns == #positions then
						for cid, col in ipairs(columns) do
							col:x(positions[cid] - engine_positions[cid])
						end
					end
					-- Side note: If the theme makes the background behind a column
					-- flash on misses or similar, moving columns this way in 5.0.12
					-- ensures that flash will *not* be lined up with the column it's
					-- meant for.  5.0.12 didn't have any support for putting something
					-- from the theme into the background for a column.
				elseif notefield.get_columns then
					-- 5.1.-3
					local columns= notefield:get_columns()
					-- Only move columns if there is a position for each column.
					if #columns == #positions then
						for cid, col in ipairs(columns) do
							col:get_column_pos_x():set_value(positions[cid])
						end
					end
					-- Colunn flashes side note continued:
					-- The notefield in 5.1.-3 has a specific place for themes to put
					-- stuff like column flashes, so the column flashes will show up in
					-- the right place in 5.1.-3.
				end
			end
		end
	end,
}