Lokasenna_Create bus before selected tracks and reroute them.lua

--[[
Description: Create bus before selected tracks and reroute them
Version: 1.0.0
Author: Lokasenna
Donation: https://paypal.me/Lokasenna
Changelog:
	Make sure sends are at unity gain, post-fader
Links:
	Lokasenna's Website http://forum.cockos.com/member.php?u=10417
About: 
	Inserts a new track before the selected tracks, labelled "Bus", then
	reroutes all selected tracks to it and disables their
  Master/Parent sends.
  
  This will only work properly for mono/stereo audio. Reaper makes
  multichannel support impractical. :(
	
--]]

-- Licensed under the GNU GPL v3

local function dMsg(str)
	if debug_mode then reaper.ShowConsoleMsg(tostring(str).."\n") end
end

local first_sel = reaper.GetSelectedTrack(0, 0)
if not first_sel then return end

reaper.Undo_BeginBlock()
reaper.PreventUIRefresh( 1 )


local idx = reaper.GetMediaTrackInfo_Value(first_sel, "IP_TRACKNUMBER") - 1
reaper.InsertTrackAtIndex(idx, true)
local bus = reaper.GetTrack(0, idx)
reaper.GetSetMediaTrackInfo_String( bus, "P_NAME", "Bus", true )


-- Loop through all tracks in the project
for i = 0, reaper.CountSelectedTracks(0) - 1 do
	
	dMsg("looking at track "..i)
	
	local tr = reaper.GetSelectedTrack(0, i)
	
	dMsg("\tdepth = "..reaper.GetTrackDepth(tr))
	dMsg("\tp_send = "..tostring( reaper.GetMediaTrackInfo_Value(tr, "B_MAINSEND") ) )
	
	dMsg("\trerouting")
	
	-- Disable Master Out
	reaper.SetMediaTrackInfo_Value(tr, "B_MAINSEND", 0)
		
    local send = reaper.CreateTrackSend(tr, bus)
    
    -- Make sure send is at unity, post-fader (overriding default send values)
    reaper.SetTrackSendInfo_Value(tr, 0, send, "D_VOL", 1)
    reaper.SetTrackSendInfo_Value(tr, 0, send, "I_SENDMODE", 0)    
	
end


reaper.PreventUIRefresh( -1 )

reaper.TrackList_AdjustWindows( false )
reaper.UpdateArrange()

reaper.Undo_EndBlock("Create bus before selected tracks and reroute them", 0)