-- check if players are playing steps with different timingdata.
local numPlayers = GAMESTATE:GetNumPlayersEnabled()

local displaySingle = Def.SongBPMDisplay {
	File=THEME:GetPathF("BPMDisplay", "bpm");
	Name="BPMDisplay";
	InitCommand=cmd(zoom,0.675;shadowlength,1);
	SetCommand=function(self) self:SetFromGameState() end;
	CurrentSongChangedMessageCommand=cmd(playcommand,"Set");
	CurrentCourseChangedMessageCommand=cmd(playcommand,"Set");
};

if numPlayers == 1 then
	return displaySingle
else
	-- check if both players are playing the same steps
	local stepsP1 = GAMESTATE:GetCurrentSteps(PLAYER_1)
	local stepsP2 = GAMESTATE:GetCurrentSteps(PLAYER_2)

	local stP1 = stepsP1:GetStepsType()
	local stP2 = stepsP2:GetStepsType()

	local diffP1 = stepsP1:GetDifficulty()
	local diffP2 = stepsP2:GetDifficulty()

	if stP1 == stP2 and diffP1 == diffP2 then
		-- both players are using the same steps; only need one.
		return displaySingle
	end

	-- otherwise, we have some more work to do.
	local timingP1 = stepsP1:GetTimingData()
	local timingP2 = stepsP2:GetTimingData()

	local function UpdateBPM(self)
		local dispP1 = self:GetChild("DisplayP1")
		local dispP2 = self:GetChild("DisplayP2")

		-- needs current bpm for p1 and p2
		for pn in ivalues(PlayerNumber) do
			local bpmDisplay = (pn == PLAYER_1) and dispP1 or dispP2
			local pState = GAMESTATE:GetPlayerState(pn);
			local songPosition = pState:GetSongPosition()
			local bpm = songPosition:GetCurBPS() * 60
			bpmDisplay:SetText( string.format(%.2f,bpm) )
		end
	end

	local displayTwoPlayers = Def.ActorFrame{
		-- manual bpm displays
		LoadFont("BPMDisplay", "bpm")..{
			Name="DisplayP1";
			InitCommand=cmd(zoom,0.675;shadowlength,1);
		};
		LoadFont("BPMDisplay", "bpm")..{
			Name="DisplayP2";
			InitCommand=cmd(zoom,0.675;shadowlength,1);
		};
	};

	displayTwoPlayers.InitCommand=cmd(SetUpdateFunction,UpdateBPM);
end